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acrac_70548_0 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | Multiple studies have shown significantly decreased length of hospital stay and decreased perioperative morbidity with EVAR [8-11] compared to open repair [12-14]. Despite this, open repair is still performed in patients with unsuitable aneurysm morphology for EVAR and in those with failed EVAR [15]. For patients who present de novo for treatment of AAA without any prior imaging available, the entire aorta (including the thoracic portion) should be assessed to fully characterize the aneurysm and exclude a concomitant thoracic aortic aneurysm. Preoperative imaging for open repair of AAA has one primary focus: to determine the need for surgery based on aneurysm size, extent, and rate of growth. Additional information regarding potential variant anatomy can also be helpful in guiding appropriate treatment and preventing unexpected complications at the time of repair. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] AAA: Interventional Planning & Follow-Up In recent years, new devices have become available to mitigate unfavorable aortic neck anatomy. Several designs feature an uncovered proximal portion that allows for placement of the stent directly at the origin of aortic branches, whereas others possess ready-made vessel origins for placement within the renal and mesenteric arteries [18]. FEVAR is an alternative approach for those with aortic necks of inadequate length. In FEVAR, fenestrations within the graft material allow for perfusion of major visceral arteries while securing an adequate proximal seal [7]. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. Multiple studies have shown significantly decreased length of hospital stay and decreased perioperative morbidity with EVAR [8-11] compared to open repair [12-14]. Despite this, open repair is still performed in patients with unsuitable aneurysm morphology for EVAR and in those with failed EVAR [15]. For patients who present de novo for treatment of AAA without any prior imaging available, the entire aorta (including the thoracic portion) should be assessed to fully characterize the aneurysm and exclude a concomitant thoracic aortic aneurysm. Preoperative imaging for open repair of AAA has one primary focus: to determine the need for surgery based on aneurysm size, extent, and rate of growth. Additional information regarding potential variant anatomy can also be helpful in guiding appropriate treatment and preventing unexpected complications at the time of repair. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] AAA: Interventional Planning & Follow-Up In recent years, new devices have become available to mitigate unfavorable aortic neck anatomy. Several designs feature an uncovered proximal portion that allows for placement of the stent directly at the origin of aortic branches, whereas others possess ready-made vessel origins for placement within the renal and mesenteric arteries [18]. FEVAR is an alternative approach for those with aortic necks of inadequate length. In FEVAR, fenestrations within the graft material allow for perfusion of major visceral arteries while securing an adequate proximal seal [7]. | 70548 |
acrac_70548_1 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | A variant of the FEVAR technique describes the placement of bridging stents through these fenestrations [23]. Such devices may be especially favorable in women, as these patients are less likely to have aneurysm neck and iliac diameters sufficient for traditional EVAR [16]. FEVAR obviates the need for open femoral exposure and offers the benefit of shorter procedure times, lower complication rates, and shorter hospital stays [5]. FEVAR requires common femoral artery anatomy that is suitable for percutaneous access and free of significant calcification. Candidates for FEVAR should be carefully selected, as the presence and degree of vessel calcification is a major determinant of technical failure [24]. The advantages of EVAR come at a cost of lifelong imaging surveillance. This is due to a higher rate of complications that require reintervention when compared to open repair [11,25]. Complications of EVAR include stent graft migration, kinking, infection, thrombosis, and renal dysfunction. The most important complication to detect is continued aneurysm expansion leading to eventual rupture, which can occur even after successful EVAR [26]. The most common complication of EVAR is endoleak formation, which may contribute to aneurysm sac enlargement and rupture [27]. Endoleaks are classified by their etiology, with Types I and III most commonly leading to rupture [15,28]. Appropriate classification is therefore crucial for subsequent management and should be clarified whenever possible. Although EVAR is safe and has a low mortality rate [29], the possibility of complications and need for reintervention remains high [12-14], thereby requiring life-long monitoring. The ultimate goal of endovascular therapy is to prevent aneurysm rupture. Follow-up imaging is the most useful tool for evaluating post-therapeutic outcomes and monitoring potential complications. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. A variant of the FEVAR technique describes the placement of bridging stents through these fenestrations [23]. Such devices may be especially favorable in women, as these patients are less likely to have aneurysm neck and iliac diameters sufficient for traditional EVAR [16]. FEVAR obviates the need for open femoral exposure and offers the benefit of shorter procedure times, lower complication rates, and shorter hospital stays [5]. FEVAR requires common femoral artery anatomy that is suitable for percutaneous access and free of significant calcification. Candidates for FEVAR should be carefully selected, as the presence and degree of vessel calcification is a major determinant of technical failure [24]. The advantages of EVAR come at a cost of lifelong imaging surveillance. This is due to a higher rate of complications that require reintervention when compared to open repair [11,25]. Complications of EVAR include stent graft migration, kinking, infection, thrombosis, and renal dysfunction. The most important complication to detect is continued aneurysm expansion leading to eventual rupture, which can occur even after successful EVAR [26]. The most common complication of EVAR is endoleak formation, which may contribute to aneurysm sac enlargement and rupture [27]. Endoleaks are classified by their etiology, with Types I and III most commonly leading to rupture [15,28]. Appropriate classification is therefore crucial for subsequent management and should be clarified whenever possible. Although EVAR is safe and has a low mortality rate [29], the possibility of complications and need for reintervention remains high [12-14], thereby requiring life-long monitoring. The ultimate goal of endovascular therapy is to prevent aneurysm rupture. Follow-up imaging is the most useful tool for evaluating post-therapeutic outcomes and monitoring potential complications. | 70548 |
acrac_70548_2 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | Successful therapy results in an aneurysm that remains stable or decreases in size over serial follow-up imaging examinations, with decreasing size of the aneurysm sac believed to indicate a low risk of future rupture [30,31]. All available imaging modalities have been investigated over time for their efficacy in post-EVAR follow-up. According to Society of Interventional Radiology guidelines, the imaging modality of choice should allow at least (1) measurement of aortic aneurysm diameter, (2) detection and classification of endoleaks, and (3) detection of morphologic details of the stent grafts [32]. Imaging modalities should be assessed by their effectiveness in satisfying these three requirements, as well as their respective safety profiles and use of potentially nephrotoxic contrast material. Overview of Imaging Modalities CT and CTA Computed tomography (CT) is a cross-sectional imaging modality that offers excellent spatial resolution, fast image acquisition times, and widespread availability. However, without contrast material administration, its ability to assess vascular structures is limited. Evaluation of the vessel lumen is accomplished through CT angiography (CTA), a technique that utilizes the administration of iodinated contrast material. The addition of 3- D volumetric postprocessing techniques allow the abdominal aorta and associated vasculature to be viewed in any obliquity and affords quantification of luminal diameter, cross-sectional area, and sac volume. A disadvantage of CTA includes potential nephrotoxicity from administered contrast material [33-35]. For the purposes of distinguishing between CT and CTA, the ACR Appropriateness Criteria topics use the definition in the Practice Parameter for the Performance and Interpretation of Body Computed Tomography Angiography (CTA) [36]: All procedure elements are essential: (1) timing, (2) recons/reformats, and (3) 3-D renderings. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. Successful therapy results in an aneurysm that remains stable or decreases in size over serial follow-up imaging examinations, with decreasing size of the aneurysm sac believed to indicate a low risk of future rupture [30,31]. All available imaging modalities have been investigated over time for their efficacy in post-EVAR follow-up. According to Society of Interventional Radiology guidelines, the imaging modality of choice should allow at least (1) measurement of aortic aneurysm diameter, (2) detection and classification of endoleaks, and (3) detection of morphologic details of the stent grafts [32]. Imaging modalities should be assessed by their effectiveness in satisfying these three requirements, as well as their respective safety profiles and use of potentially nephrotoxic contrast material. Overview of Imaging Modalities CT and CTA Computed tomography (CT) is a cross-sectional imaging modality that offers excellent spatial resolution, fast image acquisition times, and widespread availability. However, without contrast material administration, its ability to assess vascular structures is limited. Evaluation of the vessel lumen is accomplished through CT angiography (CTA), a technique that utilizes the administration of iodinated contrast material. The addition of 3- D volumetric postprocessing techniques allow the abdominal aorta and associated vasculature to be viewed in any obliquity and affords quantification of luminal diameter, cross-sectional area, and sac volume. A disadvantage of CTA includes potential nephrotoxicity from administered contrast material [33-35]. For the purposes of distinguishing between CT and CTA, the ACR Appropriateness Criteria topics use the definition in the Practice Parameter for the Performance and Interpretation of Body Computed Tomography Angiography (CTA) [36]: All procedure elements are essential: (1) timing, (2) recons/reformats, and (3) 3-D renderings. | 70548 |
acrac_70548_3 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | Standard CTs with contrast also include timing issues and recons/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that CMS has applied to the CPT codes. CTA imaging may be performed as a single arterial phase, biphasic study (noncontrast and arterial or arterial and delayed phases), or as a triphasic study (noncontrast, arterial, and delayed phases). To reduce the cumulative lifetime radiation dose of patients undergoing CTA surveillance, several authors have proposed eliminating either AAA: Interventional Planning & Follow-Up the arterial phase [37] or delayed phase [38,39], although one author has suggested eliminating noncontrast scans from all surveillance examinations with the exception of an initial 1-month follow-up [40]. Several studies have reported significant dose reduction using dual-energy CT with acquisition of delayed-phase images only [41,42]. Accompanying software allows for the isolation of iodine from a selected region and enables reconstruction of virtual noncontrast images. A colored overlay can be applied to voxels containing iodine, rendering detection of contrast material within the aneurysm sac external to the stent-graft more visible [41]. Dual-phase dual-energy CT can potentially reduce the radiation dose by 19.5% when compared to a standard triphasic CT examination [34]. Additional dose reduction techniques include the use of automatic exposure control and iterative reconstruction algorithms [34]. Determining the optimal dose-efficient CT technique is a work in progress that will continue to evolve with increased experience and technological advancement. Aortography Aortography is an invasive imaging modality that can accurately assess aortic side branch patency, knowledge of which is crucial for deployment of conventional and fenestrated endografts with or without bridging stents. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. Standard CTs with contrast also include timing issues and recons/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that CMS has applied to the CPT codes. CTA imaging may be performed as a single arterial phase, biphasic study (noncontrast and arterial or arterial and delayed phases), or as a triphasic study (noncontrast, arterial, and delayed phases). To reduce the cumulative lifetime radiation dose of patients undergoing CTA surveillance, several authors have proposed eliminating either AAA: Interventional Planning & Follow-Up the arterial phase [37] or delayed phase [38,39], although one author has suggested eliminating noncontrast scans from all surveillance examinations with the exception of an initial 1-month follow-up [40]. Several studies have reported significant dose reduction using dual-energy CT with acquisition of delayed-phase images only [41,42]. Accompanying software allows for the isolation of iodine from a selected region and enables reconstruction of virtual noncontrast images. A colored overlay can be applied to voxels containing iodine, rendering detection of contrast material within the aneurysm sac external to the stent-graft more visible [41]. Dual-phase dual-energy CT can potentially reduce the radiation dose by 19.5% when compared to a standard triphasic CT examination [34]. Additional dose reduction techniques include the use of automatic exposure control and iterative reconstruction algorithms [34]. Determining the optimal dose-efficient CT technique is a work in progress that will continue to evolve with increased experience and technological advancement. Aortography Aortography is an invasive imaging modality that can accurately assess aortic side branch patency, knowledge of which is crucial for deployment of conventional and fenestrated endografts with or without bridging stents. | 70548 |
acrac_70548_4 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | However, it fails to demonstrate mural thrombus, thereby limiting diameter measurements and landing zone assessment. Though less sensitive than CTA in detecting endoleaks, aortography is able to demonstrate the direction of blood flow in or out of the aneurysm sac, rendering it more accurate than CTA in classifying endoleaks [43]. Although traditional aortography relies on iodinated contrast material, recent studies suggest that carbon dioxide may be an acceptable alternative for evaluating endoleaks in patients at risk for contrast-related nephropathy [44,45]. MRA The major advantage of MR angiography (MRA) relative to CTA is improved soft tissue characterization. Despite relatively low nephrotoxicity, gadolinium-based contrast media (GBCM) have been linked to nephrogenic systemic fibrosis (NSF) [46]. As such, evaluation of renal function in high-risk patients before administering a GBCM long scanning duration, patient claustrophobia, decreased spatial resolution, and contraindication in patients with certain implantable devices. MRA is also limited in its ability to detect intimal calcification [33]. Additionally, susceptibility artifact from the metal interstices of the stent graft presents a diagnostic challenge for assessing device integrity and may mimic graft stenosis. Although the presence of an implanted cardiac pacemaker was previously an absolute contraindication to MRI, several new models are FDA-approved for conditional use. Superior soft-tissue characterization inherent to MRA may assist clinicians in differentiating slow-growing aneurysms from fast-growing aneurysms. A recent study demonstrated that AAAs containing intraluminal thrombus that have high T1-weighted signal intensity are associated with higher growth rates [47]. US Color duplex ultrasound (CDUS) is a noninvasive imaging modality that is portable and safe, sparing patients from nephrotoxic contrast material administration. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. However, it fails to demonstrate mural thrombus, thereby limiting diameter measurements and landing zone assessment. Though less sensitive than CTA in detecting endoleaks, aortography is able to demonstrate the direction of blood flow in or out of the aneurysm sac, rendering it more accurate than CTA in classifying endoleaks [43]. Although traditional aortography relies on iodinated contrast material, recent studies suggest that carbon dioxide may be an acceptable alternative for evaluating endoleaks in patients at risk for contrast-related nephropathy [44,45]. MRA The major advantage of MR angiography (MRA) relative to CTA is improved soft tissue characterization. Despite relatively low nephrotoxicity, gadolinium-based contrast media (GBCM) have been linked to nephrogenic systemic fibrosis (NSF) [46]. As such, evaluation of renal function in high-risk patients before administering a GBCM long scanning duration, patient claustrophobia, decreased spatial resolution, and contraindication in patients with certain implantable devices. MRA is also limited in its ability to detect intimal calcification [33]. Additionally, susceptibility artifact from the metal interstices of the stent graft presents a diagnostic challenge for assessing device integrity and may mimic graft stenosis. Although the presence of an implanted cardiac pacemaker was previously an absolute contraindication to MRI, several new models are FDA-approved for conditional use. Superior soft-tissue characterization inherent to MRA may assist clinicians in differentiating slow-growing aneurysms from fast-growing aneurysms. A recent study demonstrated that AAAs containing intraluminal thrombus that have high T1-weighted signal intensity are associated with higher growth rates [47]. US Color duplex ultrasound (CDUS) is a noninvasive imaging modality that is portable and safe, sparing patients from nephrotoxic contrast material administration. | 70548 |
acrac_70548_5 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | CDUS is able to assess blood flow dynamics in real-time and allows for quantification of luminal diameter and cross-sectional area. Image quality in CDUS is highly dependent on operator experience, patient cooperation, and patient body habitus [48,49]. Although excellent correlation between AAA diameter measurements made by CT and CDUS is well documented, there is general agreement that conventional ultrasound (US) techniques systematically underestimate aneurysm diameter by ~2 mm [35,50-52]. Contrast-enhanced ultrasound (CEUS) utilizes the infusion of stabilized sodium hexafluoride gas to visualize the vessel lumen. Unlike iodinated contrast materials used in CTA, this gas is not nephrotoxic and is safely eliminated via the respiratory system. The advent of 3-D CEUS utilizes positional information for magnetic field emitters to assemble collected US reflections into a high-resolution 3-D image, which results in improved image quality relative to CDUS [53]. 3-D CEUS is reported to be more accurate than 2-D methods in quantifying maximum vessel diameter, as the former allows measurements to be made orthogonal to vessel centerline [50]. For patients with absolute contraindications to iodinated contrast material, whether due to severe renal impairment or life-threatening contrast allergy, US is an important adjunct to nonenhanced CT. AAA: Interventional Planning & Follow-Up Discussion of Procedures by Variant Variant 1: Planning for pre-endovascular repair (EVAR) or open repair of AAA. Radiography Radiographs are unable to adequately visualize the abdominal aorta, thereby prohibiting proximal landing zone assessment and luminal diameter quantification. As such, there is no role for radiography in the preoperative evaluation of AAA. However, given the high spatial resolution of radiography, this modality affords optimal visualization of stent graft geometry. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. CDUS is able to assess blood flow dynamics in real-time and allows for quantification of luminal diameter and cross-sectional area. Image quality in CDUS is highly dependent on operator experience, patient cooperation, and patient body habitus [48,49]. Although excellent correlation between AAA diameter measurements made by CT and CDUS is well documented, there is general agreement that conventional ultrasound (US) techniques systematically underestimate aneurysm diameter by ~2 mm [35,50-52]. Contrast-enhanced ultrasound (CEUS) utilizes the infusion of stabilized sodium hexafluoride gas to visualize the vessel lumen. Unlike iodinated contrast materials used in CTA, this gas is not nephrotoxic and is safely eliminated via the respiratory system. The advent of 3-D CEUS utilizes positional information for magnetic field emitters to assemble collected US reflections into a high-resolution 3-D image, which results in improved image quality relative to CDUS [53]. 3-D CEUS is reported to be more accurate than 2-D methods in quantifying maximum vessel diameter, as the former allows measurements to be made orthogonal to vessel centerline [50]. For patients with absolute contraindications to iodinated contrast material, whether due to severe renal impairment or life-threatening contrast allergy, US is an important adjunct to nonenhanced CT. AAA: Interventional Planning & Follow-Up Discussion of Procedures by Variant Variant 1: Planning for pre-endovascular repair (EVAR) or open repair of AAA. Radiography Radiographs are unable to adequately visualize the abdominal aorta, thereby prohibiting proximal landing zone assessment and luminal diameter quantification. As such, there is no role for radiography in the preoperative evaluation of AAA. However, given the high spatial resolution of radiography, this modality affords optimal visualization of stent graft geometry. | 70548 |
acrac_70548_6 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | When utilizing consistent centering protocols, this allows for reliable detection of kinks and stent graft migration to within 2 mm [54]. CT and CTA Due to its superior spatial resolution and rapid image acquisition, CTA with 3-D volumetric reconstruction and vessel analysis has gained wide acceptance as the gold standard for pre-EVAR evaluation. The utilization of 3-D reconstruction software has become paramount in EVAR planning, as it diminishes the impact of vessel tortuosity on diameter and length measurements, in addition to reducing intraobserver variability [55]. One author found that routine 3-D analysis of pre-EVAR images led to a significant reduction in Type I endoleaks [56]. Reformatted CTA images in the coronal and sagittal planes should be utilized for increased diagnostic accuracy. In most cases, a CTA of the abdomen and pelvis is appropriate to ensure coverage of the entire aneurysm and vascular access. The CTA should include the chest in patients with thoracoabdominal aortic aneurysms (TAAA). Aortography As aortography and radiography are unable to accurately provide aneurysm sac diameter measurements and landing zone assessment, these modalities are inadequate for pre-EVAR or open repair evaluation. However, aortography may be of value in assessing branch vessel patency and is usually part of branch vessel occlusion procedures before aneurysm repair. MRA For the purpose of pre-EVAR planning, T1-weighted spin-echo images and flow-based methods such as time of flight or phase contrast provide adequate details regarding aneurysm morphology and relevant vascular anatomy. However, these techniques are limited by low spatial resolution and signal-to-noise ratio and are therefore suboptimal for evaluating small-vessel lesions or diminutive side branches [33]. Furthermore, flow-based sequences are susceptible to flow artifacts that may overestimate the degree of stenosis or falsely demonstrate an occlusion [57]. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. When utilizing consistent centering protocols, this allows for reliable detection of kinks and stent graft migration to within 2 mm [54]. CT and CTA Due to its superior spatial resolution and rapid image acquisition, CTA with 3-D volumetric reconstruction and vessel analysis has gained wide acceptance as the gold standard for pre-EVAR evaluation. The utilization of 3-D reconstruction software has become paramount in EVAR planning, as it diminishes the impact of vessel tortuosity on diameter and length measurements, in addition to reducing intraobserver variability [55]. One author found that routine 3-D analysis of pre-EVAR images led to a significant reduction in Type I endoleaks [56]. Reformatted CTA images in the coronal and sagittal planes should be utilized for increased diagnostic accuracy. In most cases, a CTA of the abdomen and pelvis is appropriate to ensure coverage of the entire aneurysm and vascular access. The CTA should include the chest in patients with thoracoabdominal aortic aneurysms (TAAA). Aortography As aortography and radiography are unable to accurately provide aneurysm sac diameter measurements and landing zone assessment, these modalities are inadequate for pre-EVAR or open repair evaluation. However, aortography may be of value in assessing branch vessel patency and is usually part of branch vessel occlusion procedures before aneurysm repair. MRA For the purpose of pre-EVAR planning, T1-weighted spin-echo images and flow-based methods such as time of flight or phase contrast provide adequate details regarding aneurysm morphology and relevant vascular anatomy. However, these techniques are limited by low spatial resolution and signal-to-noise ratio and are therefore suboptimal for evaluating small-vessel lesions or diminutive side branches [33]. Furthermore, flow-based sequences are susceptible to flow artifacts that may overestimate the degree of stenosis or falsely demonstrate an occlusion [57]. | 70548 |
acrac_70548_7 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | To overcome these limitations, contrast-enhanced MRA (CE-MRA) should be added to conventional T1- and T2-weighted spin-echo sequences. CE-MRA is much less susceptible to flow and susceptibility artifacts and has a high signal-to-noise ratio for evaluating small vessels and fine structural details. The effectiveness of CE-MRA has been found to be comparable to that of CTA in assessing the suitability of aneurysms for EVAR [58]. In most cases, an MRA of the abdomen and pelvis is appropriate to ensure coverage of the entire aneurysm and vascular access. The MRA should include the chest in patients with TAAA. Acquisition of noncontrast balanced steady state free precession (bSSFP) images may be useful in the preoperative evaluation of patients who poorly tolerate GBCM or are at risk for NSF. One study found that AAA measurements obtained by noncontrast MRA were not significantly different from those measured by CTA [59]. US Although the United States Preventative Services Task Force currently recommends one-time US screening for AAA in men ages 65 to 75 years who have ever smoked [60], no evidence is present within the medical literature to support the use of either CDUS or CEUS in the formal preoperative evaluation of AAA. Variant 2: Follow-up for post-endovascular repair (EVAR) or open repair of AAA. CT and CTA The exceptional spatial resolution and fast imaging speeds of CTA has made it the de facto gold standard for post- EVAR and post-open repair imaging surveillance. After EVAR, the most widely used surveillance regimen utilizes multiphasic contrast-enhanced CT at 1 month, 12 months, and yearly thereafter. If an abnormality is detected 1 month post-EVAR, a follow-up scan at 6 months is performed. In the absence of adverse outcomes at the 1-month follow-up imaging, the intensity and frequency of the surveillance program may be modulated accordingly [61-64]. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. To overcome these limitations, contrast-enhanced MRA (CE-MRA) should be added to conventional T1- and T2-weighted spin-echo sequences. CE-MRA is much less susceptible to flow and susceptibility artifacts and has a high signal-to-noise ratio for evaluating small vessels and fine structural details. The effectiveness of CE-MRA has been found to be comparable to that of CTA in assessing the suitability of aneurysms for EVAR [58]. In most cases, an MRA of the abdomen and pelvis is appropriate to ensure coverage of the entire aneurysm and vascular access. The MRA should include the chest in patients with TAAA. Acquisition of noncontrast balanced steady state free precession (bSSFP) images may be useful in the preoperative evaluation of patients who poorly tolerate GBCM or are at risk for NSF. One study found that AAA measurements obtained by noncontrast MRA were not significantly different from those measured by CTA [59]. US Although the United States Preventative Services Task Force currently recommends one-time US screening for AAA in men ages 65 to 75 years who have ever smoked [60], no evidence is present within the medical literature to support the use of either CDUS or CEUS in the formal preoperative evaluation of AAA. Variant 2: Follow-up for post-endovascular repair (EVAR) or open repair of AAA. CT and CTA The exceptional spatial resolution and fast imaging speeds of CTA has made it the de facto gold standard for post- EVAR and post-open repair imaging surveillance. After EVAR, the most widely used surveillance regimen utilizes multiphasic contrast-enhanced CT at 1 month, 12 months, and yearly thereafter. If an abnormality is detected 1 month post-EVAR, a follow-up scan at 6 months is performed. In the absence of adverse outcomes at the 1-month follow-up imaging, the intensity and frequency of the surveillance program may be modulated accordingly [61-64]. | 70548 |
acrac_70548_8 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | Compared to aortography, CTA has higher sensitivity in detecting endoleaks after EVAR. Compared to US, CTA is better able to visualize kinking and migration of the stent-graft and is equivalent in quantifying aneurysm sac size [34] . AAA: Interventional Planning & Follow-Up Initial post-EVAR surveillance studies monitored the maximum diameter of the aneurysm sac as a marker for response to therapy [65]. This method has been shown to be unreliable due to substantial interobserver variability [66]. Volume analysis of the aneurysm sac has since proven to be the most reliable indicator for aneurysm rupture and/or need for reintervention [67-69]. In an effort to reduce radiation dose and contrast material exposure, several authors have proposed using serial volumetric analysis of AAAs with noncontrast CT as the sole screening test for post-EVAR follow-up [70-73]. Volume discrepancy due to interoperator variability has been demonstrated to be less than 2% when the procedure is performed by experienced personnel [72,74]. In patients in whom contrast materials are contraindicated, serial volume measurements of the nonenhanced aneurysm sac provides valuable information in guiding management [75]. In most cases, a CTA of the abdomen and pelvis is appropriate to ensure coverage of the treated aneurysm and stent graft. The CTA should include the chest in patients with TAAA. Aortography Due to the relatively invasive nature of aortography, it is not practical for routine post-EVAR surveillance. However, in the setting of a known endoleak, aortography may be more accurate than CTA in classifying endoleaks. One study revealed only 86% agreement in endoleak classification between aortography and CTA, in which subsequent correct classification by aortography significantly improved patient management [43]. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. Compared to aortography, CTA has higher sensitivity in detecting endoleaks after EVAR. Compared to US, CTA is better able to visualize kinking and migration of the stent-graft and is equivalent in quantifying aneurysm sac size [34] . AAA: Interventional Planning & Follow-Up Initial post-EVAR surveillance studies monitored the maximum diameter of the aneurysm sac as a marker for response to therapy [65]. This method has been shown to be unreliable due to substantial interobserver variability [66]. Volume analysis of the aneurysm sac has since proven to be the most reliable indicator for aneurysm rupture and/or need for reintervention [67-69]. In an effort to reduce radiation dose and contrast material exposure, several authors have proposed using serial volumetric analysis of AAAs with noncontrast CT as the sole screening test for post-EVAR follow-up [70-73]. Volume discrepancy due to interoperator variability has been demonstrated to be less than 2% when the procedure is performed by experienced personnel [72,74]. In patients in whom contrast materials are contraindicated, serial volume measurements of the nonenhanced aneurysm sac provides valuable information in guiding management [75]. In most cases, a CTA of the abdomen and pelvis is appropriate to ensure coverage of the treated aneurysm and stent graft. The CTA should include the chest in patients with TAAA. Aortography Due to the relatively invasive nature of aortography, it is not practical for routine post-EVAR surveillance. However, in the setting of a known endoleak, aortography may be more accurate than CTA in classifying endoleaks. One study revealed only 86% agreement in endoleak classification between aortography and CTA, in which subsequent correct classification by aortography significantly improved patient management [43]. | 70548 |
acrac_70548_9 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | It therefore stands to reason that aortography may be best utilized as a second-line imaging modality in post-EVAR patients, playing a vital role in endoleak classification and reintervention [35]. MRA When considering using MRA for post-EVAR surveillance, stent material and orientation are important considerations. Typical stent construction employs nitinol, elgiloy, or stainless steel. Nitinol is a nickel-titanium alloy that causes relatively few artifacts on MRA, while allowing adequate visualization of the stent lumen and adjacent structures. Elgiloy is an alloy of cobalt, chromium, and nickel that may obscure the stent lumen but still allows for visualization of adjacent structures. Patients with nitinol stents are the optimal candidates for MRA, while those with elgiloy or stainless steel stents may experience significant artifacts that compromise visualization of the stent lumen and limit morphological resolution of the stent wall [76]. However, artifacts may arise even with nitinol stents secondary to stent geometry [77]. Due to severe susceptibility artifact associated with stainless steel embolization coils, MRA is poor in the follow-up of patients who have undergone coil embolization of the internal iliac artery before EVAR [35]. MRA of the post-EVAR aorta shares multiple features with CTA. Like CTA, isotropic 3-D MRA images may be reformatted in any plane for volume analysis or orthogonal diameter measurements. In patients with nitinol stents, aortic diameter measurements for MRA have been shown to be as reliable as those obtained with CTA [78]. MRA has been shown to be more sensitive than CTA for the detection of endoleaks [35,79]. Consequently, the higher rate of endoleak detection seen by MRA in cases with a negative CTA may shed light on the phenomenon of endotension [80]. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. It therefore stands to reason that aortography may be best utilized as a second-line imaging modality in post-EVAR patients, playing a vital role in endoleak classification and reintervention [35]. MRA When considering using MRA for post-EVAR surveillance, stent material and orientation are important considerations. Typical stent construction employs nitinol, elgiloy, or stainless steel. Nitinol is a nickel-titanium alloy that causes relatively few artifacts on MRA, while allowing adequate visualization of the stent lumen and adjacent structures. Elgiloy is an alloy of cobalt, chromium, and nickel that may obscure the stent lumen but still allows for visualization of adjacent structures. Patients with nitinol stents are the optimal candidates for MRA, while those with elgiloy or stainless steel stents may experience significant artifacts that compromise visualization of the stent lumen and limit morphological resolution of the stent wall [76]. However, artifacts may arise even with nitinol stents secondary to stent geometry [77]. Due to severe susceptibility artifact associated with stainless steel embolization coils, MRA is poor in the follow-up of patients who have undergone coil embolization of the internal iliac artery before EVAR [35]. MRA of the post-EVAR aorta shares multiple features with CTA. Like CTA, isotropic 3-D MRA images may be reformatted in any plane for volume analysis or orthogonal diameter measurements. In patients with nitinol stents, aortic diameter measurements for MRA have been shown to be as reliable as those obtained with CTA [78]. MRA has been shown to be more sensitive than CTA for the detection of endoleaks [35,79]. Consequently, the higher rate of endoleak detection seen by MRA in cases with a negative CTA may shed light on the phenomenon of endotension [80]. | 70548 |
acrac_70548_10 | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up | More recently, time-resolved MRA has been used in the characterization of endoleaks and may provide relevant information regarding contrast and flow dynamics within endoleaks [35]. As such, replacing aortography as an effective and noninvasive method for endoleak characterization shows promise [81]. In most cases, MRA of the abdomen and pelvis is appropriate to ensure coverage of the treated aneurysm and stent graft. The MRA should include the chest in patients with TAAA. Blood pool contrast materials such as ferumoxytol [82,83] remain intravascular for a prolonged duration, thereby allowing for generation of high-resolution 3-D multiplanar images [82,83]. Use of these contrast materials may improve detection of slow-flow endoleaks [82,83]. Patients intolerant of GBCM or those at risk for NSF may benefit from the acquisition of noncontrast bSSFP images in post-EVAR surveillance. One small retrospective study found that noncontrast bSSFP images can be used to exclude endoleak after EVAR, with postcontrast imaging reserved for verification and further characterization of a suspected endoleak [84]. US CDUS and CEUS are being increasingly recommended for post-EVAR follow-up. These are convenient, noninvasive, and have a favorable safety profile. In the evaluation of endoleak, CDUS has high specificity but limited sensitivity, reported in two large meta-analyses to be 91% to 93% and 66% to 69%, respectively [85,86]. The major limitations of US are the inability to detect stent-graft kinking, fracture, migration, or component AAA: Interventional Planning & Follow-Up separation [87-89]. For this reason, adjunct four-view radiographs are recommended to be obtained with all post- EVAR US examinations [49,53,84,87,89,90]. For FEVARs that involve the celiac trunk, US is unable to adequately visualize the proximal sealing zone [89]. Not unexpectedly, published results regarding the accuracy of CDUS in post-EVAR follow-up are varied [51,85,91-93]. | Abdominal Aortic Aneurysm or Dissection Interventional Planning and Follow up. More recently, time-resolved MRA has been used in the characterization of endoleaks and may provide relevant information regarding contrast and flow dynamics within endoleaks [35]. As such, replacing aortography as an effective and noninvasive method for endoleak characterization shows promise [81]. In most cases, MRA of the abdomen and pelvis is appropriate to ensure coverage of the treated aneurysm and stent graft. The MRA should include the chest in patients with TAAA. Blood pool contrast materials such as ferumoxytol [82,83] remain intravascular for a prolonged duration, thereby allowing for generation of high-resolution 3-D multiplanar images [82,83]. Use of these contrast materials may improve detection of slow-flow endoleaks [82,83]. Patients intolerant of GBCM or those at risk for NSF may benefit from the acquisition of noncontrast bSSFP images in post-EVAR surveillance. One small retrospective study found that noncontrast bSSFP images can be used to exclude endoleak after EVAR, with postcontrast imaging reserved for verification and further characterization of a suspected endoleak [84]. US CDUS and CEUS are being increasingly recommended for post-EVAR follow-up. These are convenient, noninvasive, and have a favorable safety profile. In the evaluation of endoleak, CDUS has high specificity but limited sensitivity, reported in two large meta-analyses to be 91% to 93% and 66% to 69%, respectively [85,86]. The major limitations of US are the inability to detect stent-graft kinking, fracture, migration, or component AAA: Interventional Planning & Follow-Up separation [87-89]. For this reason, adjunct four-view radiographs are recommended to be obtained with all post- EVAR US examinations [49,53,84,87,89,90]. For FEVARs that involve the celiac trunk, US is unable to adequately visualize the proximal sealing zone [89]. Not unexpectedly, published results regarding the accuracy of CDUS in post-EVAR follow-up are varied [51,85,91-93]. | 70548 |
acrac_3195152_0 | Penetrating Torso Trauma | Introduction/Background Penetrating torso trauma occurs when a foreign body disrupts the skin and enters the patient. The anatomical boundaries of the torso begin cranially at the thoracic inlet and caudally at the inferior margins of the greater trochanters, excluding the appendicular skeletal structures. Penetrating trauma most commonly occurs from gunshots and stabbings, although any object can impale the patient. High rates of mortality and morbidity are associated with gunshot wounds, with approximately 42,222 deaths in 2020 or 13.7 deaths per 100,000 people [1]. Stab wounds are much more common, estimated at 434,259 injuries annually; however, these wounds rarely result in death. According to the Centers for Disease Control and Prevention, between 2003 and 2019, a total number of 6,015 deaths were reported in the United States from stab injuries [1]. Special Imaging Considerations Imaging, in particular multidetector CT, plays a central role in guiding management in patients with penetrating trauma. Contrast-enhanced CT with multiplanar reformations is the standard imaging tool in the evaluation of patients with penetrating trauma due to its fast acquisition and excellent resolution [2,3]. Single versus multiphasic protocols vary depending upon both institutional protocols and clinical presentation. Multiphasic protocols that include an arterial phase may improve the identification and characterization of vascular injuries, whereas the assessment of solid organs in the abdomen and pelvis is best performed during the portal venous phase [6]. Furthermore, the American Association for the Surgery of Trauma recommends dual-phase CT (arterial and venous phases) for accurate diagnosis of vascular injuries of the solid organs including the spleen, liver, or kidney [7]. Throughout this manuscript, CT angiography (CTA) will presuppose at least 2 postcontrast phases of imaging in addition to the angiography phase. | Penetrating Torso Trauma. Introduction/Background Penetrating torso trauma occurs when a foreign body disrupts the skin and enters the patient. The anatomical boundaries of the torso begin cranially at the thoracic inlet and caudally at the inferior margins of the greater trochanters, excluding the appendicular skeletal structures. Penetrating trauma most commonly occurs from gunshots and stabbings, although any object can impale the patient. High rates of mortality and morbidity are associated with gunshot wounds, with approximately 42,222 deaths in 2020 or 13.7 deaths per 100,000 people [1]. Stab wounds are much more common, estimated at 434,259 injuries annually; however, these wounds rarely result in death. According to the Centers for Disease Control and Prevention, between 2003 and 2019, a total number of 6,015 deaths were reported in the United States from stab injuries [1]. Special Imaging Considerations Imaging, in particular multidetector CT, plays a central role in guiding management in patients with penetrating trauma. Contrast-enhanced CT with multiplanar reformations is the standard imaging tool in the evaluation of patients with penetrating trauma due to its fast acquisition and excellent resolution [2,3]. Single versus multiphasic protocols vary depending upon both institutional protocols and clinical presentation. Multiphasic protocols that include an arterial phase may improve the identification and characterization of vascular injuries, whereas the assessment of solid organs in the abdomen and pelvis is best performed during the portal venous phase [6]. Furthermore, the American Association for the Surgery of Trauma recommends dual-phase CT (arterial and venous phases) for accurate diagnosis of vascular injuries of the solid organs including the spleen, liver, or kidney [7]. Throughout this manuscript, CT angiography (CTA) will presuppose at least 2 postcontrast phases of imaging in addition to the angiography phase. | 3195152 |
acrac_3195152_1 | Penetrating Torso Trauma | When there is suspicion or knowledge of renal injury, delayed excretory phase imaging should be acquired [8]. In addition to intravenous (IV) administration of contrast, some institutions advocate the administration of oral and rectal contrast when there is concern for bowel injury in the setting of aUniversity of Kentucky, Lexington, Kentucky; Committee on Emergency Radiology-GSER. bResearch Author, University of Kentucky, Lexington, Kentucky. cHackensack University Medical Center, Hackensack, New Jersey; American Association for the Surgery of Trauma. dMayo Clinic Arizona; Committee on Emergency Radiology-GSER. eUniversity of Toronto and Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. fUniversity of California Davis Health, Sacramento, California; Society for Academic Emergency Medicine. gMassachusetts General Hospital, Boston, Massachusetts. hVancouver General Hospital, Vancouver, British Columbia, Canada; Committee on Emergency Radiology-GSER. iPCP - Internal medicine, University of Kentucky, Lexington, Kentucky. jPennsylvania State University College of Medicine, Hershey, Pennsylvania; American College of Emergency Physicians. kR. Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, Maryland. lUniversity of Washington, Seattle, Washington; Committee on Emergency Radiology-GSER. mRadiology Associates of Hollywood, Pembroke Pines, Florida. nSpecialty Chair, Ohio State University Wexner Medical Center, Columbus, Ohio. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] Penetrating Torso Trauma penetrating trauma [9,10]. | Penetrating Torso Trauma. When there is suspicion or knowledge of renal injury, delayed excretory phase imaging should be acquired [8]. In addition to intravenous (IV) administration of contrast, some institutions advocate the administration of oral and rectal contrast when there is concern for bowel injury in the setting of aUniversity of Kentucky, Lexington, Kentucky; Committee on Emergency Radiology-GSER. bResearch Author, University of Kentucky, Lexington, Kentucky. cHackensack University Medical Center, Hackensack, New Jersey; American Association for the Surgery of Trauma. dMayo Clinic Arizona; Committee on Emergency Radiology-GSER. eUniversity of Toronto and Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. fUniversity of California Davis Health, Sacramento, California; Society for Academic Emergency Medicine. gMassachusetts General Hospital, Boston, Massachusetts. hVancouver General Hospital, Vancouver, British Columbia, Canada; Committee on Emergency Radiology-GSER. iPCP - Internal medicine, University of Kentucky, Lexington, Kentucky. jPennsylvania State University College of Medicine, Hershey, Pennsylvania; American College of Emergency Physicians. kR. Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, Maryland. lUniversity of Washington, Seattle, Washington; Committee on Emergency Radiology-GSER. mRadiology Associates of Hollywood, Pembroke Pines, Florida. nSpecialty Chair, Ohio State University Wexner Medical Center, Columbus, Ohio. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] Penetrating Torso Trauma penetrating trauma [9,10]. | 3195152 |
acrac_3195152_2 | Penetrating Torso Trauma | Radiography and focused assessment with ultrasonography for trauma (FAST) play an important role in triage, often directing next step management [11-17]. The role of FAST (or extended-FAST or chest abdominal-FAST in evaluating chest injury) is primarily one of triage; a positive FAST and signs of hemodynamic instability may lead to immediate surgical intervention rather than CT [18,19]. Ultrasound (US) may be able to diagnose certain thoracic and abdominal injuries, but it is an insufficient test to fully exclude injuries to these areas because it has a relatively lower specificity compared with CT [20]. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. Some trauma systems also use prehospital FAST to expedite management upon arrival to the hospital [14,16]. CT Chest, Abdomen, and Pelvis With IV Contrast Traditionally and in most practices, patients with penetrating trauma demonstrating signs of hemodynamic instability would be operatively managed without CT imaging [24]. However, recently, some authors recommend whole-body CT while continuing resuscitation regardless of hemodynamic status [25,26]. Proponents of this approach suggest the information gathered during CT helps determine the optimal surgical approach and prevents delay of definitive management. The degree of hemodynamic instability and distance to the CT scanner should be accounted for when deciding upon use of CT in this clinical scenario. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. | Penetrating Torso Trauma. Radiography and focused assessment with ultrasonography for trauma (FAST) play an important role in triage, often directing next step management [11-17]. The role of FAST (or extended-FAST or chest abdominal-FAST in evaluating chest injury) is primarily one of triage; a positive FAST and signs of hemodynamic instability may lead to immediate surgical intervention rather than CT [18,19]. Ultrasound (US) may be able to diagnose certain thoracic and abdominal injuries, but it is an insufficient test to fully exclude injuries to these areas because it has a relatively lower specificity compared with CT [20]. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. Some trauma systems also use prehospital FAST to expedite management upon arrival to the hospital [14,16]. CT Chest, Abdomen, and Pelvis With IV Contrast Traditionally and in most practices, patients with penetrating trauma demonstrating signs of hemodynamic instability would be operatively managed without CT imaging [24]. However, recently, some authors recommend whole-body CT while continuing resuscitation regardless of hemodynamic status [25,26]. Proponents of this approach suggest the information gathered during CT helps determine the optimal surgical approach and prevents delay of definitive management. The degree of hemodynamic instability and distance to the CT scanner should be accounted for when deciding upon use of CT in this clinical scenario. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. | 3195152 |
acrac_3195152_3 | Penetrating Torso Trauma | If CT imaging is performed in this patient population, the imaging time should be minimized as much as possible, and therefore without IV contrast imaging is not routinely recommended. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. If CT imaging is performed in this patient population, IV contrast should be administered. CTA Chest, Abdomen, and Pelvis IV Contrast Most literature supporting the use of multiphase CTA imaging in the torso is derived from the blunt trauma patient population [27]. Literature suggests the detection of vascular injury is similar between routine contrast-enhanced CT of the chest and CTA of the chest; however, the justification for performing routine contrast-enhanced CT of the chest and CTA imaging was to reduce the need for two separate contrast injections [28]. Most modern-day CT Penetrating Torso Trauma scanners and protocols enable imaging of the entire body in multiple phases with one IV contrast bolus [29]. If imaging is pursued in this imaging population, single-phase imaging to include the portal venous phase may provide the most relevant information for next step imaging. MRI Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. MRI Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. Radiography Trauma Series Chest radiographs can recognize contusions, pneumothorax, hemothorax, rib fractures, foreign bodies and/or ballistic fragments, and mediastinal injuries, which could be treated immediately. | Penetrating Torso Trauma. If CT imaging is performed in this patient population, the imaging time should be minimized as much as possible, and therefore without IV contrast imaging is not routinely recommended. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. If CT imaging is performed in this patient population, IV contrast should be administered. CTA Chest, Abdomen, and Pelvis IV Contrast Most literature supporting the use of multiphase CTA imaging in the torso is derived from the blunt trauma patient population [27]. Literature suggests the detection of vascular injury is similar between routine contrast-enhanced CT of the chest and CTA of the chest; however, the justification for performing routine contrast-enhanced CT of the chest and CTA imaging was to reduce the need for two separate contrast injections [28]. Most modern-day CT Penetrating Torso Trauma scanners and protocols enable imaging of the entire body in multiple phases with one IV contrast bolus [29]. If imaging is pursued in this imaging population, single-phase imaging to include the portal venous phase may provide the most relevant information for next step imaging. MRI Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. MRI Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. Radiography Trauma Series Chest radiographs can recognize contusions, pneumothorax, hemothorax, rib fractures, foreign bodies and/or ballistic fragments, and mediastinal injuries, which could be treated immediately. | 3195152 |
acrac_3195152_4 | Penetrating Torso Trauma | Radiographic evaluation can also help identify retained foreign bodies and suggest trajectory, which may direct initial surgical exploration. Variant 2: Adult. Ballistic penetrating torso trauma, unknown trajectory, normotensive. Initial imaging. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. Some trauma systems also use prehospital FAST to expedite management upon arrival to the hospital [14,16]. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma. The addition of a noncontrast phase may delay definitive diagnosis and typically does not provide additional information pertinent to penetrating trauma [31]. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without IV contrast for initial evaluation of penetrating torso trauma. Although noncontrast CT may be helpful in determining trajectory, demonstration of internal injuries, specifically solid organs, is much more apparent with IV contrast. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [32]. CTA Chest, Abdomen, and Pelvis IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. | Penetrating Torso Trauma. Radiographic evaluation can also help identify retained foreign bodies and suggest trajectory, which may direct initial surgical exploration. Variant 2: Adult. Ballistic penetrating torso trauma, unknown trajectory, normotensive. Initial imaging. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. Some trauma systems also use prehospital FAST to expedite management upon arrival to the hospital [14,16]. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma. The addition of a noncontrast phase may delay definitive diagnosis and typically does not provide additional information pertinent to penetrating trauma [31]. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without IV contrast for initial evaluation of penetrating torso trauma. Although noncontrast CT may be helpful in determining trajectory, demonstration of internal injuries, specifically solid organs, is much more apparent with IV contrast. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [32]. CTA Chest, Abdomen, and Pelvis IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. | 3195152 |
acrac_3195152_5 | Penetrating Torso Trauma | In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. For example, a hemodynamically stable patient with active arterial bleeding may be treated with an angioembolization procedure, whereas bleeding from a venous structure may result in supportive care [29,33]. MRI Chest, Abdomen, and Pelvis Without And With IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. Penetrating Torso Trauma MRI Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. Radiography Trauma Series Chest radiographs can recognize contusions, pneumothorax, hemothorax, rib fractures, foreign bodies and/or ballistic fragments, and mediastinal injuries, which should be treated immediately. Radiographic evaluation can also help identify retained foreign bodies and suggest trajectory which may direct initial surgical exploration. CT Abdomen and Pelvis With IV Contrast CT could be performed if there is suspected suspicion for intraperitoneal violation. Overall, liberal use of imaging in ballistic trauma is recommend because the trajectory can be unpredictable. Diaphragmatic excursion may be high at time of injury, making intra-abdominal injuries difficult to exclude. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of adding a noncontrast phase to a contrast-enhanced CT abdomen and pelvis for initial evaluation of penetrating torso trauma limited to the chest. | Penetrating Torso Trauma. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. For example, a hemodynamically stable patient with active arterial bleeding may be treated with an angioembolization procedure, whereas bleeding from a venous structure may result in supportive care [29,33]. MRI Chest, Abdomen, and Pelvis Without And With IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. Penetrating Torso Trauma MRI Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. Radiography Trauma Series Chest radiographs can recognize contusions, pneumothorax, hemothorax, rib fractures, foreign bodies and/or ballistic fragments, and mediastinal injuries, which should be treated immediately. Radiographic evaluation can also help identify retained foreign bodies and suggest trajectory which may direct initial surgical exploration. CT Abdomen and Pelvis With IV Contrast CT could be performed if there is suspected suspicion for intraperitoneal violation. Overall, liberal use of imaging in ballistic trauma is recommend because the trajectory can be unpredictable. Diaphragmatic excursion may be high at time of injury, making intra-abdominal injuries difficult to exclude. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of adding a noncontrast phase to a contrast-enhanced CT abdomen and pelvis for initial evaluation of penetrating torso trauma limited to the chest. | 3195152 |
acrac_3195152_6 | Penetrating Torso Trauma | CT Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without IV contrast for initial evaluation of penetrating torso trauma. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CT Chest Without And With IV Contrast There is no relevant literature regarding the usefulness of adding a noncontrast phase to a contrast-enhanced CT chest for initial evaluation of penetrating torso trauma limited to the chest CT Chest Without IV Contrast During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. Noncontrast imaging of the chest is inadequate to definitively evaluate the chest for vascular injuries in the setting of ballistic trauma isolated to the chest. CTA Abdomen and Pelvis With IV Contrast Nummela et al [29] concluded that CTA of the whole body is recommended because multiple injuries and active bleeding are common in penetrating thoracic trauma. CTA of the abdomen and pelvis should be used liberally because the terminal ballistics of bullets and other fragments may have an unpredictable trajectory. CTA Chest With IV Contrast CTA of the chest is a valuable modality in assessment of penetrating transmediastinal injury in hemodynamically stable patients. It can guide immediate surgical intervention versus expectant management in conjunction with Penetrating Torso Trauma transesophageal echocardiogram [38]. CTA may better demonstrate pseudoaneurysm, vascular occlusion, active contrast extravasation, intimal tear, and early venous filling in arteriovenous fistulas. MRI Abdomen and Pelvis Without And With IV Contrast There is no relevant literature regarding the use of MRI abdomen and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. | Penetrating Torso Trauma. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without IV contrast for initial evaluation of penetrating torso trauma. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CT Chest Without And With IV Contrast There is no relevant literature regarding the usefulness of adding a noncontrast phase to a contrast-enhanced CT chest for initial evaluation of penetrating torso trauma limited to the chest CT Chest Without IV Contrast During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. Noncontrast imaging of the chest is inadequate to definitively evaluate the chest for vascular injuries in the setting of ballistic trauma isolated to the chest. CTA Abdomen and Pelvis With IV Contrast Nummela et al [29] concluded that CTA of the whole body is recommended because multiple injuries and active bleeding are common in penetrating thoracic trauma. CTA of the abdomen and pelvis should be used liberally because the terminal ballistics of bullets and other fragments may have an unpredictable trajectory. CTA Chest With IV Contrast CTA of the chest is a valuable modality in assessment of penetrating transmediastinal injury in hemodynamically stable patients. It can guide immediate surgical intervention versus expectant management in conjunction with Penetrating Torso Trauma transesophageal echocardiogram [38]. CTA may better demonstrate pseudoaneurysm, vascular occlusion, active contrast extravasation, intimal tear, and early venous filling in arteriovenous fistulas. MRI Abdomen and Pelvis Without And With IV Contrast There is no relevant literature regarding the use of MRI abdomen and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. | 3195152 |
acrac_3195152_7 | Penetrating Torso Trauma | MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI abdomen and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest Without And With IV Contrast There is no relevant literature regarding the use of MRI chest without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest Without IV Contrast There is no relevant literature regarding the use of MRI chest without IV contrast for initial evaluation of patients with penetrating torso trauma. Radiography Trauma Series Chest radiographs can recognize contusions, pneumothorax, hemothorax, rib fractures, foreign bodies and/or ballistic fragments, and mediastinal injuries, which could be treated immediately. Radiographic evaluation can also help identify retained foreign bodies and suggest trajectory, which may direct initial surgical exploration. Some authors suggest that a chest radiograph may be adequate in this patient population, and CT identifies additional findings that do not require surgical intervention [41]. Other authors, however, point out the limitations of chest radiography [42]. Berg et al [43] found that patients with penetrating thoracic trauma or asymptomatic patients with unremarkable initial chest radiographs can be safely discharged by short-term repeat chest radiographs. CT Abdomen and Pelvis Without And With IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma. The addition of a noncontrast phase does not provide additional information pertinent to penetrating trauma [31]. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without IV contrast for initial evaluation of penetrating torso trauma. | Penetrating Torso Trauma. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI abdomen and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest Without And With IV Contrast There is no relevant literature regarding the use of MRI chest without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest Without IV Contrast There is no relevant literature regarding the use of MRI chest without IV contrast for initial evaluation of patients with penetrating torso trauma. Radiography Trauma Series Chest radiographs can recognize contusions, pneumothorax, hemothorax, rib fractures, foreign bodies and/or ballistic fragments, and mediastinal injuries, which could be treated immediately. Radiographic evaluation can also help identify retained foreign bodies and suggest trajectory, which may direct initial surgical exploration. Some authors suggest that a chest radiograph may be adequate in this patient population, and CT identifies additional findings that do not require surgical intervention [41]. Other authors, however, point out the limitations of chest radiography [42]. Berg et al [43] found that patients with penetrating thoracic trauma or asymptomatic patients with unremarkable initial chest radiographs can be safely discharged by short-term repeat chest radiographs. CT Abdomen and Pelvis Without And With IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma. The addition of a noncontrast phase does not provide additional information pertinent to penetrating trauma [31]. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without IV contrast for initial evaluation of penetrating torso trauma. | 3195152 |
acrac_3195152_8 | Penetrating Torso Trauma | During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CT Chest With IV Contrast Given the unpredictable trajectory of ballistic trauma, liberal use of CT imaging of the chest is typically performed when there is presumed isolated abdominal and pelvic trauma [2]. Penetrating Torso Trauma CT Chest Without and With IV Contrast There is no relevant literature regarding the use of CT chest without and with IV contrast for initial evaluation of penetrating torso trauma. The addition of a noncontrast phase does not provide additional information pertinent to penetrating trauma [31]. CT Chest Without IV Contrast There is no relevant literature regarding the use of CT chest without IV contrast for initial evaluation of penetrating torso trauma. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CTA Abdomen and Pelvis With IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. For example, a hemodynamically stable patient with active arterial bleeding may be treated with an angioembolization procedure, whereas bleeding from a venous structure may result in supportive care [29,33]. | Penetrating Torso Trauma. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CT Chest With IV Contrast Given the unpredictable trajectory of ballistic trauma, liberal use of CT imaging of the chest is typically performed when there is presumed isolated abdominal and pelvic trauma [2]. Penetrating Torso Trauma CT Chest Without and With IV Contrast There is no relevant literature regarding the use of CT chest without and with IV contrast for initial evaluation of penetrating torso trauma. The addition of a noncontrast phase does not provide additional information pertinent to penetrating trauma [31]. CT Chest Without IV Contrast There is no relevant literature regarding the use of CT chest without IV contrast for initial evaluation of penetrating torso trauma. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CTA Abdomen and Pelvis With IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. For example, a hemodynamically stable patient with active arterial bleeding may be treated with an angioembolization procedure, whereas bleeding from a venous structure may result in supportive care [29,33]. | 3195152 |
acrac_3195152_9 | Penetrating Torso Trauma | CTA Chest With IV Contrast CTA of the chest is now routinely used for both blunt and penetrating trauma at many level 1 trauma centers. CTA may better demonstrate pseudoaneurysm, vascular occlusion, active contrast extravasation, intimal tear, and early venous filling in arteriovenous fistulas [29,48]. MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of MRI abdomen and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI abdomen and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest Without and With IV Contrast There is no relevant literature regarding the use of MRI chest without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest Without IV Contrast There is no relevant literature regarding the use of MRI chest without IV contrast for initial evaluation of patients with penetrating torso trauma. Radiography Trauma Series It is common practice at many trauma centers to mark presumed penetrating wounds with radiodense markers. Radiographic evaluation can help identify retained foreign bodies and suggest trajectory, which may direct additional imaging or mandate surgical exploration. Variant 5: Adult. Nonballistic penetrating torso trauma, unknown trajectory, normotensive. Initial imaging. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. Some trauma systems also use prehospital FAST to expedite management upon arrival to the hospital [14,16]. Penetrating Torso Trauma the sites of skin violation, which is much more important with sharp object low energy penetrating trauma. | Penetrating Torso Trauma. CTA Chest With IV Contrast CTA of the chest is now routinely used for both blunt and penetrating trauma at many level 1 trauma centers. CTA may better demonstrate pseudoaneurysm, vascular occlusion, active contrast extravasation, intimal tear, and early venous filling in arteriovenous fistulas [29,48]. MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of MRI abdomen and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI abdomen and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest Without and With IV Contrast There is no relevant literature regarding the use of MRI chest without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest Without IV Contrast There is no relevant literature regarding the use of MRI chest without IV contrast for initial evaluation of patients with penetrating torso trauma. Radiography Trauma Series It is common practice at many trauma centers to mark presumed penetrating wounds with radiodense markers. Radiographic evaluation can help identify retained foreign bodies and suggest trajectory, which may direct additional imaging or mandate surgical exploration. Variant 5: Adult. Nonballistic penetrating torso trauma, unknown trajectory, normotensive. Initial imaging. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. Some trauma systems also use prehospital FAST to expedite management upon arrival to the hospital [14,16]. Penetrating Torso Trauma the sites of skin violation, which is much more important with sharp object low energy penetrating trauma. | 3195152 |
acrac_3195152_10 | Penetrating Torso Trauma | Additional information should be sought regarding blade length or the presence of bruising or a "hilt mark" at the skin entry site when evaluating stab wounds. Single-acquisition whole torso-imaging is preferred over segmental imaging so that the tract of the wound can be followed [2]. CT Chest, Abdomen, and Pelvis Without And With IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma. The addition of a noncontrast does not provide additional information pertinent to penetrating trauma [31]. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without IV contrast for initial evaluation of penetrating torso trauma. Although noncontrast CT may be helpful in determining trajectory, demonstration of internal injuries, specifically solid organs, is much more apparent with IV contrast. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CTA Chest, Abdomen, and Pelvis IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. | Penetrating Torso Trauma. Additional information should be sought regarding blade length or the presence of bruising or a "hilt mark" at the skin entry site when evaluating stab wounds. Single-acquisition whole torso-imaging is preferred over segmental imaging so that the tract of the wound can be followed [2]. CT Chest, Abdomen, and Pelvis Without And With IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma. The addition of a noncontrast does not provide additional information pertinent to penetrating trauma [31]. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT chest, abdomen, and pelvis without IV contrast for initial evaluation of penetrating torso trauma. Although noncontrast CT may be helpful in determining trajectory, demonstration of internal injuries, specifically solid organs, is much more apparent with IV contrast. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CTA Chest, Abdomen, and Pelvis IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. | 3195152 |
acrac_3195152_11 | Penetrating Torso Trauma | For example, a hemodynamically stable patient with active arterial bleeding may be treated with an angioembolization procedure, whereas bleeding from a venous structure may result in supportive care [29,33]. MRI Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. Radiography Trauma Series Chest radiographs can recognize contusions, pneumothorax, hemothorax, rib fractures, retained foreign bodies, and mediastinal injuries, which should be treated immediately. Radiographic evaluation can also help identify retained foreign bodies and suggest trajectory, which may direct initial surgical exploration. The limitations of radiography, particularly chest radiography, should be understood in the setting of nonballistic trauma. Nguyen et al [50] showed that greater than one-third of patients in their study had additional findings on CT after a normal screening chest radiograph. Variant 6: Adult. Nonballistic penetrating torso trauma, limited to chest, normotensive. Initial imaging. Injuries that are considered limited to the chest occur outside of the thoracoabdominal zone. Anatomical landmarks can include above the nipple line in men or above the fourth rib. Wounds occurring below these anatomical landmarks could involve abdominal structures given significant diaphragmatic excursion. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. | Penetrating Torso Trauma. For example, a hemodynamically stable patient with active arterial bleeding may be treated with an angioembolization procedure, whereas bleeding from a venous structure may result in supportive care [29,33]. MRI Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. Radiography Trauma Series Chest radiographs can recognize contusions, pneumothorax, hemothorax, rib fractures, retained foreign bodies, and mediastinal injuries, which should be treated immediately. Radiographic evaluation can also help identify retained foreign bodies and suggest trajectory, which may direct initial surgical exploration. The limitations of radiography, particularly chest radiography, should be understood in the setting of nonballistic trauma. Nguyen et al [50] showed that greater than one-third of patients in their study had additional findings on CT after a normal screening chest radiograph. Variant 6: Adult. Nonballistic penetrating torso trauma, limited to chest, normotensive. Initial imaging. Injuries that are considered limited to the chest occur outside of the thoracoabdominal zone. Anatomical landmarks can include above the nipple line in men or above the fourth rib. Wounds occurring below these anatomical landmarks could involve abdominal structures given significant diaphragmatic excursion. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. | 3195152 |
acrac_3195152_12 | Penetrating Torso Trauma | Some trauma systems also use prehospital FAST to expedite management upon arrival to the hospital [14,16]. CT Abdomen and Pelvis With IV Contrast It is useful to get CT scans of the abdomen and pelvis if there is suspicion of peritoneal violation or possible diaphragmatic injuries. Penetrating Torso Trauma CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma isolated to the chest and does not provide additional information pertinent to penetrating trauma [31]. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without IV contrast for initial evaluation of penetrating torso trauma isolated to the chest. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CT Chest With IV Contrast Contrast-enhanced chest CT is an effective screening tool for determining the wound trajectory and likelihood of injury to mediastinal structures. CT can guide the decision-making process in management of patients in whom immediate surgical intervention could be performed with positive findings at CT chest [51]. If CT shows no evidence of mediastinal injury or other thoracic injury requiring surgery, the patient can simply be observed [37]. CT Chest Without And With IV Contrast There is no relevant literature regarding the use of CT chest without and with IV contrast for initial evaluation of penetrating torso trauma isolated to the chest. The addition of a noncontrast phase does not provide additional information pertinent to penetrating trauma [31]. CT Chest Without IV Contrast Although noncontrast CT may be helpful in determining trajectory, demonstration of internal injuries, specifically solid organs, is much more apparent with IV contrast. | Penetrating Torso Trauma. Some trauma systems also use prehospital FAST to expedite management upon arrival to the hospital [14,16]. CT Abdomen and Pelvis With IV Contrast It is useful to get CT scans of the abdomen and pelvis if there is suspicion of peritoneal violation or possible diaphragmatic injuries. Penetrating Torso Trauma CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma isolated to the chest and does not provide additional information pertinent to penetrating trauma [31]. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without IV contrast for initial evaluation of penetrating torso trauma isolated to the chest. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CT Chest With IV Contrast Contrast-enhanced chest CT is an effective screening tool for determining the wound trajectory and likelihood of injury to mediastinal structures. CT can guide the decision-making process in management of patients in whom immediate surgical intervention could be performed with positive findings at CT chest [51]. If CT shows no evidence of mediastinal injury or other thoracic injury requiring surgery, the patient can simply be observed [37]. CT Chest Without And With IV Contrast There is no relevant literature regarding the use of CT chest without and with IV contrast for initial evaluation of penetrating torso trauma isolated to the chest. The addition of a noncontrast phase does not provide additional information pertinent to penetrating trauma [31]. CT Chest Without IV Contrast Although noncontrast CT may be helpful in determining trajectory, demonstration of internal injuries, specifically solid organs, is much more apparent with IV contrast. | 3195152 |
acrac_3195152_13 | Penetrating Torso Trauma | Vascular injuries are also better depicted with IV contrast. CT chest without IV contrast can effectively excluded pneumothorax and hemothorax [50]. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CTA Abdomen and Pelvis With IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. CTA Chest With IV Contrast In the hemodynamically stable patient population, CTA can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. For example, a hemodynamically stable patient with active arterial bleeding may be treated with an angioembolization procedure, whereas bleeding from a venous structure may result in supportive care [29,33]. MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. | Penetrating Torso Trauma. Vascular injuries are also better depicted with IV contrast. CT chest without IV contrast can effectively excluded pneumothorax and hemothorax [50]. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CTA Abdomen and Pelvis With IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. CTA Chest With IV Contrast In the hemodynamically stable patient population, CTA can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. For example, a hemodynamically stable patient with active arterial bleeding may be treated with an angioembolization procedure, whereas bleeding from a venous structure may result in supportive care [29,33]. MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without and with IV contrast for initial evaluation of patients with penetrating torso trauma. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of MRI chest, abdomen, and pelvis without IV contrast for initial evaluation of patients with penetrating torso trauma with hypotension. | 3195152 |
acrac_3195152_14 | Penetrating Torso Trauma | MRI Chest Without and With IV Contrast There is no relevant literature regarding the use of MRI chest without and with IV contrast only for initial evaluation of patients with penetrating torso trauma. MRI Chest Without IV Contrast There is no relevant literature regarding the use of MRI chest without IV contrast only for initial evaluation of patients with penetrating torso trauma. Penetrating Torso Trauma Radiography Trauma Series Penetrating trauma occurring outside of the thoracoabdominal zones and the cardiac box maybe sufficiently imaged with radiography in clinically stable patients [51]. Normal radiographic appearance of the chest does not preclude significant thoracic trauma that may require procedural or surgical intervention [50]. Variant 7: Adult. Nonballistic penetrating torso trauma, limited to abdomen and pelvis, normotensive. Initial imaging. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma isolated to the chest. The addition of a noncontrast phase adds radiation exposure to the patient and may delay definitive diagnosis and typically does not provide additional information pertinent to penetrating trauma [31]. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without IV contrast for initial evaluation of penetrating torso trauma. Although noncontrast CT may be helpful in determining trajectory, demonstration of internal injuries, specifically solid organs, is much more apparent with IV contrast. | Penetrating Torso Trauma. MRI Chest Without and With IV Contrast There is no relevant literature regarding the use of MRI chest without and with IV contrast only for initial evaluation of patients with penetrating torso trauma. MRI Chest Without IV Contrast There is no relevant literature regarding the use of MRI chest without IV contrast only for initial evaluation of patients with penetrating torso trauma. Penetrating Torso Trauma Radiography Trauma Series Penetrating trauma occurring outside of the thoracoabdominal zones and the cardiac box maybe sufficiently imaged with radiography in clinically stable patients [51]. Normal radiographic appearance of the chest does not preclude significant thoracic trauma that may require procedural or surgical intervention [50]. Variant 7: Adult. Nonballistic penetrating torso trauma, limited to abdomen and pelvis, normotensive. Initial imaging. FAST can help triage patients and direct initial bedside and surgical procedures. Hemopericardium, pneumothorax, and free intraperitoneal fluid discovered at FAST have significant implications on next steps in management of the patient. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without and with IV contrast for initial evaluation of penetrating torso trauma isolated to the chest. The addition of a noncontrast phase adds radiation exposure to the patient and may delay definitive diagnosis and typically does not provide additional information pertinent to penetrating trauma [31]. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature regarding the use of CT abdomen and pelvis without IV contrast for initial evaluation of penetrating torso trauma. Although noncontrast CT may be helpful in determining trajectory, demonstration of internal injuries, specifically solid organs, is much more apparent with IV contrast. | 3195152 |
acrac_3195152_15 | Penetrating Torso Trauma | During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CT Chest With IV Contrast CT chest may be used if there is suspicion of supradiaphragmatic injury involving the lungs, heart, diaphragm, or pleural space. CT Chest Without and With IV Contrast There is no relevant literature regarding the use of CT chest without and with IV contrast for initial evaluation of penetrating torso trauma limited to the abdomen and pelvis. CT Chest Without IV Contrast There is no relevant literature regarding the use of CT chest without IV contrast for initial evaluation of penetrating torso trauma limited to the abdomen and pelvis. The addition of a noncontrast phase does not provide additional information pertinent to penetrating trauma [31]. CTA Abdomen and Pelvis With IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. CTA Chest With IV Contrast In the hemodynamically stable patient population, CTA can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. | Penetrating Torso Trauma. During the global shortage of contrast in 2022, unenhanced CT scans were used for acute and posttraumatic patients in emergency departments at some institutions [36]. CT Chest With IV Contrast CT chest may be used if there is suspicion of supradiaphragmatic injury involving the lungs, heart, diaphragm, or pleural space. CT Chest Without and With IV Contrast There is no relevant literature regarding the use of CT chest without and with IV contrast for initial evaluation of penetrating torso trauma limited to the abdomen and pelvis. CT Chest Without IV Contrast There is no relevant literature regarding the use of CT chest without IV contrast for initial evaluation of penetrating torso trauma limited to the abdomen and pelvis. The addition of a noncontrast phase does not provide additional information pertinent to penetrating trauma [31]. CTA Abdomen and Pelvis With IV Contrast In the hemodynamically stable patient population, multiphasic imaging can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. CTA Chest With IV Contrast In the hemodynamically stable patient population, CTA can provide additional useful information regarding the source of active bleeding. Additionally, it is important to remember that imaging can be performed after damage control surgery to identify injuries that may need definitive treatment [29,33]. In their retrospective study, Nummela et al [29] found that arterial and venous phases of the chest, abdomen, and pelvis CT facilitated recognition of active bleeding in patients with penetrating thoracic trauma. Differentiating between arterial and venous hemorrhage may have treatment implications. | 3195152 |
acrac_69374_0 | Renovascular Hypertension | Introduction/Background Hypertension is a common condition, affecting approximately 20% of adults. Secondary hypertension (ie, hypertension with a demonstrable cause) accounts for only 5% to 10% of all cases of hypertension, with the remaining cases considered primary hypertension or essential hypertension. Renovascular hypertension is the most common type of secondary hypertension and is estimated to have a prevalence between 0.5% and 5% of the general hypertensive population, and it has an even higher prevalence among patients with severe hypertension and end-stage renal disease, approaching 25% in elderly dialysis patients [1]. There are varied causes of reduced renal perfusion with resultant renovascular hypertension, the most common being renal artery stenosis (RAS) secondary to either atherosclerotic disease (90%) or fibromuscular dysplasia (10%) [2]. Less common etiologies include vasculitis, embolic disease, dissection, post-traumatic occlusion, and extrinsic compression of a renal artery or of a kidney [3]. Clinical features associated with an increased likelihood of renovascular hypertension include an abdominal bruit, malignant or accelerated hypertension, significant (diastolic pressure >110 mm Hg) hypertension in a young adult (<35 years of age), new onset after 50 years of age, sudden development or worsening of hypertension, refractory hypertension, deterioration of renal function in response to angiotensin- converting enzyme inhibitors, and generalized arteriosclerotic occlusive disease with hypertension. A critical problem in diagnosing renovascular hypertension is the selection of an appropriate end point against which to judge the accuracy of new tests. Calculations of the sensitivity, specificity, and accuracy of these examinations are normally based on a comparison with a standard such as conventional angiography. However, the definition of a significant RAS has varied. | Renovascular Hypertension. Introduction/Background Hypertension is a common condition, affecting approximately 20% of adults. Secondary hypertension (ie, hypertension with a demonstrable cause) accounts for only 5% to 10% of all cases of hypertension, with the remaining cases considered primary hypertension or essential hypertension. Renovascular hypertension is the most common type of secondary hypertension and is estimated to have a prevalence between 0.5% and 5% of the general hypertensive population, and it has an even higher prevalence among patients with severe hypertension and end-stage renal disease, approaching 25% in elderly dialysis patients [1]. There are varied causes of reduced renal perfusion with resultant renovascular hypertension, the most common being renal artery stenosis (RAS) secondary to either atherosclerotic disease (90%) or fibromuscular dysplasia (10%) [2]. Less common etiologies include vasculitis, embolic disease, dissection, post-traumatic occlusion, and extrinsic compression of a renal artery or of a kidney [3]. Clinical features associated with an increased likelihood of renovascular hypertension include an abdominal bruit, malignant or accelerated hypertension, significant (diastolic pressure >110 mm Hg) hypertension in a young adult (<35 years of age), new onset after 50 years of age, sudden development or worsening of hypertension, refractory hypertension, deterioration of renal function in response to angiotensin- converting enzyme inhibitors, and generalized arteriosclerotic occlusive disease with hypertension. A critical problem in diagnosing renovascular hypertension is the selection of an appropriate end point against which to judge the accuracy of new tests. Calculations of the sensitivity, specificity, and accuracy of these examinations are normally based on a comparison with a standard such as conventional angiography. However, the definition of a significant RAS has varied. | 69374 |
acrac_69374_1 | Renovascular Hypertension | Most investigators consider a 50% to 60% stenosis to be significant, yet perfusion pressure in a large artery is generally not reduced until stenosis exceeds 70% to 75%. Ultimately, the defining criterion for renovascular hypertension is a fall in blood pressure after intervention (angioplasty, intravascular stent placement, or surgery). Bilateral renal artery disease remains a problem in that it is difficult in such cases to quantify the effect on blood pressure of one side versus the other. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Renovascular Hypertension Discussion of Procedures by Variant Variant 1: High index of suspicion of renovascular hypertension. Normal renal function. US Duplex Doppler US is an attractive technique as a noninvasive screening test in that it does not require intravenous contrast material and can be used in patients with any level of renal function. As with many of the noninvasive imaging examinations, there are numerous parameters and abnormal criteria indicating possible renovascular disease. Doppler US can also be used for detection of significant renal artery in-stent restenosis, though studies have shown that compared with native renal arteries, higher PSV and RAR values are indicative of stenosis in stented arteries. Chi et al [18], in a study of 67 patients with renal artery stents, found that a PSV of at least 395 cm/s or RAR of at least 5.1 was most predictive of significant in-stent stenosis. Similarly, Del Conde et al [19], in a study of 132 stented renal arteries, reported a mean PSV of 382 cm/s and RAR of 5.3 in arteries with >60% stenosis. Renovascular Hypertension | Renovascular Hypertension. Most investigators consider a 50% to 60% stenosis to be significant, yet perfusion pressure in a large artery is generally not reduced until stenosis exceeds 70% to 75%. Ultimately, the defining criterion for renovascular hypertension is a fall in blood pressure after intervention (angioplasty, intravascular stent placement, or surgery). Bilateral renal artery disease remains a problem in that it is difficult in such cases to quantify the effect on blood pressure of one side versus the other. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Renovascular Hypertension Discussion of Procedures by Variant Variant 1: High index of suspicion of renovascular hypertension. Normal renal function. US Duplex Doppler US is an attractive technique as a noninvasive screening test in that it does not require intravenous contrast material and can be used in patients with any level of renal function. As with many of the noninvasive imaging examinations, there are numerous parameters and abnormal criteria indicating possible renovascular disease. Doppler US can also be used for detection of significant renal artery in-stent restenosis, though studies have shown that compared with native renal arteries, higher PSV and RAR values are indicative of stenosis in stented arteries. Chi et al [18], in a study of 67 patients with renal artery stents, found that a PSV of at least 395 cm/s or RAR of at least 5.1 was most predictive of significant in-stent stenosis. Similarly, Del Conde et al [19], in a study of 132 stented renal arteries, reported a mean PSV of 382 cm/s and RAR of 5.3 in arteries with >60% stenosis. Renovascular Hypertension | 69374 |
acrac_69374_2 | Renovascular Hypertension | Although Doppler US is a preferred screening tool for RAS, it is time-consuming and highly operator dependent, and MRI or CT may be more reliable modalities for operators who are less experienced with US for RAS. Nuclear Medicine Renal scintigraphy was first used for evaluating renal function in the late 1950s. Initial attempts to use renography specifically for evaluating renovascular hypertension had a high rate of false-positive and false-negative results. Captopril was later added to the examination in an attempt to improve the accuracy of the test for diagnosing renovascular hypertension and for predicting blood pressure reduction after surgery or angioplasty. Administration of an angiotensin-converting enzyme inhibitor such as captopril leads to a decrease in glomerular filtration pressure, prolonged transit time of tubular agents such as Tc-99m-MAG3, and decreased uptake of glomerular agents such as Tc-99m-diethylenetriaminepentaacetic acid. Captopril renal scintigraphy analysis is based on characterization of renal function deterioration when compared with a baseline study, with decreased glomerular filtration rate reflected in time-activity curves. Captopril renography is therefore a functional assessment of renal perfusion and function rather than a method of directly visualizing the vasculature. The sensitivity and specificity of this examination are decreased in patients without clinical features of renovascular hypertension and are also decreased in patients with bilateral RAS, impaired renal function, and urinary obstruction [20]. The reported sensitivity of captopril renal scintigraphy for renovascular hypertension ranges from 34% to 93%, with a meta-analysis of 14 studies between 1990 and 2000 by Vasbinder et al [21] showing a mean sensitivity of approximately 81%. There have also been inconsistent results regarding the predictive value of captopril renal scintigraphy in identifying patients who will respond to revascularization. | Renovascular Hypertension. Although Doppler US is a preferred screening tool for RAS, it is time-consuming and highly operator dependent, and MRI or CT may be more reliable modalities for operators who are less experienced with US for RAS. Nuclear Medicine Renal scintigraphy was first used for evaluating renal function in the late 1950s. Initial attempts to use renography specifically for evaluating renovascular hypertension had a high rate of false-positive and false-negative results. Captopril was later added to the examination in an attempt to improve the accuracy of the test for diagnosing renovascular hypertension and for predicting blood pressure reduction after surgery or angioplasty. Administration of an angiotensin-converting enzyme inhibitor such as captopril leads to a decrease in glomerular filtration pressure, prolonged transit time of tubular agents such as Tc-99m-MAG3, and decreased uptake of glomerular agents such as Tc-99m-diethylenetriaminepentaacetic acid. Captopril renal scintigraphy analysis is based on characterization of renal function deterioration when compared with a baseline study, with decreased glomerular filtration rate reflected in time-activity curves. Captopril renography is therefore a functional assessment of renal perfusion and function rather than a method of directly visualizing the vasculature. The sensitivity and specificity of this examination are decreased in patients without clinical features of renovascular hypertension and are also decreased in patients with bilateral RAS, impaired renal function, and urinary obstruction [20]. The reported sensitivity of captopril renal scintigraphy for renovascular hypertension ranges from 34% to 93%, with a meta-analysis of 14 studies between 1990 and 2000 by Vasbinder et al [21] showing a mean sensitivity of approximately 81%. There have also been inconsistent results regarding the predictive value of captopril renal scintigraphy in identifying patients who will respond to revascularization. | 69374 |
acrac_69374_3 | Renovascular Hypertension | High correlation between a positive result on captopril renal scintigraphy and reduction in blood pressure after intervention has been reported in some studies [22]. However, the predictive value has been dismissed in other studies, with reported positive predictive values as low as 51% [23-26]. In summary, captopril renal scintigraphy has decreased sensitivity and specificity in patients with bilateral stenosis and impaired renal function, but it can be a useful tool for detecting renovascular hypertension in appropriately selected patients. As a functional evaluation of renal perfusion and function, captopril scintigraphy can be useful to determine the physiologic sequence of a known stenosis and to assess the relative function of each kidney before intervention [27,28]. MRA MRA is suited for noninvasive workup of RAS and has been widely applied in clinical practice. The reliability of MRA is not affected by the presence of bilateral renovascular disease. It is unnecessary to hydrate the patients or to stop diuretics before the examination. Three-dimensional contrast-enhanced MRA with an intravenous injection of gadolinium-based contrast agent has been the backbone of MRI examinations of renal arteries, but noncontrast MRA with steady-state free precession (SSFP) and arterial spin labeling techniques has also been used for evaluating the renal arteries. CTA CTA Contrast-enhanced CTA provides accurate anatomic images of the renal arteries with isotropic data sets that enable the reconstruction of high-resolution images in any plane. As with conventional angiography, the disadvantages of this technique are its ionizing radiation and its use of nephrotoxic contrast material. Advantages compared with arteriography include less invasiveness, faster acquisitions, and multiplanar imaging [40]. Two | Renovascular Hypertension. High correlation between a positive result on captopril renal scintigraphy and reduction in blood pressure after intervention has been reported in some studies [22]. However, the predictive value has been dismissed in other studies, with reported positive predictive values as low as 51% [23-26]. In summary, captopril renal scintigraphy has decreased sensitivity and specificity in patients with bilateral stenosis and impaired renal function, but it can be a useful tool for detecting renovascular hypertension in appropriately selected patients. As a functional evaluation of renal perfusion and function, captopril scintigraphy can be useful to determine the physiologic sequence of a known stenosis and to assess the relative function of each kidney before intervention [27,28]. MRA MRA is suited for noninvasive workup of RAS and has been widely applied in clinical practice. The reliability of MRA is not affected by the presence of bilateral renovascular disease. It is unnecessary to hydrate the patients or to stop diuretics before the examination. Three-dimensional contrast-enhanced MRA with an intravenous injection of gadolinium-based contrast agent has been the backbone of MRI examinations of renal arteries, but noncontrast MRA with steady-state free precession (SSFP) and arterial spin labeling techniques has also been used for evaluating the renal arteries. CTA CTA Contrast-enhanced CTA provides accurate anatomic images of the renal arteries with isotropic data sets that enable the reconstruction of high-resolution images in any plane. As with conventional angiography, the disadvantages of this technique are its ionizing radiation and its use of nephrotoxic contrast material. Advantages compared with arteriography include less invasiveness, faster acquisitions, and multiplanar imaging [40]. Two | 69374 |
acrac_69374_4 | Renovascular Hypertension | Renovascular Hypertension studies comparing CTA with digital renal arteriography have reported the sensitivity of CTA for detecting stenoses (>50% diameter) to be 88% to 96% and the specificity to be 77% to 98%, and in one study the accuracy was 89%. In diagnosing narrowing of only the main renal arteries, one study found the sensitivity and specificity to be 100% and 98%, respectively [41,42]. Normal results from CTA virtually rule out RAS. Both maximum- intensity projection and volume-rendering techniques are useful and complementary in CT evaluation of RAS [43]. Secondary signs include poststenotic dilatation, renal atrophy, and decreased cortical enhancement. A threshold of 800 mm2 for cortical area and 8 mm for mean cortical thickness seen on CT can be useful morphologic markers of atherosclerotic renal disease [44]. Like MRA, CTA is more accurate in diagnosing proximal rather than distal lesions, though in general CTA provides better depiction of branch renal arteries than MRA [45]. CTA can also be used to assess patency of renal stents [44,46,47]. Steinwender et al [48] described CTA evaluation of 95 renal artery stents in which 98% of the stents were assessable on CTA, and there was 100% sensitivity and 99% specificity for detecting in-stent stenosis. Arteriography Intra-arterial digital subtraction angiography (IADSA) is considered the reference standard for demonstrating RAS and is an integral part of angioplasty and stenting procedures. Angiography has high spatial resolution for evaluating the main renal arteries as well as the branch renal arteries. There is high interobserver agreement for identification of severe stenoses by angiography [49], but there is reported substantial interobserver variability in visual estimation of moderate RAS. IADSA allows for measurement of pressure gradients across a stenosis, providing assessment of its hemodynamic significance before intervention. | Renovascular Hypertension. Renovascular Hypertension studies comparing CTA with digital renal arteriography have reported the sensitivity of CTA for detecting stenoses (>50% diameter) to be 88% to 96% and the specificity to be 77% to 98%, and in one study the accuracy was 89%. In diagnosing narrowing of only the main renal arteries, one study found the sensitivity and specificity to be 100% and 98%, respectively [41,42]. Normal results from CTA virtually rule out RAS. Both maximum- intensity projection and volume-rendering techniques are useful and complementary in CT evaluation of RAS [43]. Secondary signs include poststenotic dilatation, renal atrophy, and decreased cortical enhancement. A threshold of 800 mm2 for cortical area and 8 mm for mean cortical thickness seen on CT can be useful morphologic markers of atherosclerotic renal disease [44]. Like MRA, CTA is more accurate in diagnosing proximal rather than distal lesions, though in general CTA provides better depiction of branch renal arteries than MRA [45]. CTA can also be used to assess patency of renal stents [44,46,47]. Steinwender et al [48] described CTA evaluation of 95 renal artery stents in which 98% of the stents were assessable on CTA, and there was 100% sensitivity and 99% specificity for detecting in-stent stenosis. Arteriography Intra-arterial digital subtraction angiography (IADSA) is considered the reference standard for demonstrating RAS and is an integral part of angioplasty and stenting procedures. Angiography has high spatial resolution for evaluating the main renal arteries as well as the branch renal arteries. There is high interobserver agreement for identification of severe stenoses by angiography [49], but there is reported substantial interobserver variability in visual estimation of moderate RAS. IADSA allows for measurement of pressure gradients across a stenosis, providing assessment of its hemodynamic significance before intervention. | 69374 |
acrac_69374_5 | Renovascular Hypertension | A pressure gradient >20 mm Hg, or >10% of mean arterial pressure, is considered to be an indicator of hemodynamic significance [50,51]. Smith et al [52], in a small study of 19 patients, reported the sensitivity and specificity of intravenous digital subtraction angiography (IVDSA) to be as high as 87%. However, false-positive rates ranged from 26% to 37%, which they attributed to limited spatial resolution, subtraction artifacts, and quantum noise. Other reported limitations of this technique have included obscuration of renal artery stenoses by overlap with opacified mesenteric vessels and also suboptimal evaluation of fibromuscular lesions [53-55]. Wilms et al [55], in a study of 45 patients, found fewer false-positives, which they attributed to technical advances and software improvements. They also reported that IVDSA grading of stenosis was accurate in 94% of cases of atherosclerotic RAS but in only 56% of fibromuscular stenosis cases. Dunnick et al [56], in a prospective study of 94 patients, reported 100% sensitivity and 93% specificity for RAS, though the 100% sensitivity was achieved in part by including inadequate examinations as positive, and the authors acknowledged the limitations of IVDSA for evaluating vessels affected by fibromuscular dysplasia. Although good results can be achieved with IVDSA, its resolution is inferior compared with that of IADSA, and it is less sensitive than IADSA for evaluating fibromuscular dysplasia and atherosclerotic stenosis of branch vessels. In addition, the contrast dose is often substantially higher than in arteriography and requires central injection in the inferior vena cava or right atrium. For these reasons, IVDSA is not utilized as a screening examination for renovascular hypertension. Renovascular Hypertension Variant 2: High index of suspicion of renovascular hypertension. Decreased renal function, eGFR <30 mL/min/1.73 m2. | Renovascular Hypertension. A pressure gradient >20 mm Hg, or >10% of mean arterial pressure, is considered to be an indicator of hemodynamic significance [50,51]. Smith et al [52], in a small study of 19 patients, reported the sensitivity and specificity of intravenous digital subtraction angiography (IVDSA) to be as high as 87%. However, false-positive rates ranged from 26% to 37%, which they attributed to limited spatial resolution, subtraction artifacts, and quantum noise. Other reported limitations of this technique have included obscuration of renal artery stenoses by overlap with opacified mesenteric vessels and also suboptimal evaluation of fibromuscular lesions [53-55]. Wilms et al [55], in a study of 45 patients, found fewer false-positives, which they attributed to technical advances and software improvements. They also reported that IVDSA grading of stenosis was accurate in 94% of cases of atherosclerotic RAS but in only 56% of fibromuscular stenosis cases. Dunnick et al [56], in a prospective study of 94 patients, reported 100% sensitivity and 93% specificity for RAS, though the 100% sensitivity was achieved in part by including inadequate examinations as positive, and the authors acknowledged the limitations of IVDSA for evaluating vessels affected by fibromuscular dysplasia. Although good results can be achieved with IVDSA, its resolution is inferior compared with that of IADSA, and it is less sensitive than IADSA for evaluating fibromuscular dysplasia and atherosclerotic stenosis of branch vessels. In addition, the contrast dose is often substantially higher than in arteriography and requires central injection in the inferior vena cava or right atrium. For these reasons, IVDSA is not utilized as a screening examination for renovascular hypertension. Renovascular Hypertension Variant 2: High index of suspicion of renovascular hypertension. Decreased renal function, eGFR <30 mL/min/1.73 m2. | 69374 |
acrac_69374_6 | Renovascular Hypertension | The selection of imaging modality and technique for evaluation of RAS may vary in the setting of decreased renal function primarily because of the risk of CIN with iodinated contrast material for CT and the risk of NSF with gadolinium-based contrast agents for MRI. US For patients with a high index of suspicion for renovascular disease and diminished renal function, duplex Doppler US is a preferred screening examination, especially at a site where the technique has proven to be reliable and where dedicated technologists and physicians are skilled in the examination and can perform it with a high degree of accuracy. The technical details of the examination and the threshold criteria are similar to those used for patients with normal renal function (see variant 1). CTA Depending on the degree of impaired renal function, contrast-enhanced CTA has been considered to be precluded because of potential nephrotoxicity of contrast material. However, the causal relationship between contrast material for CT and acute kidney injury has been disputed, and recent data suggest a low risk of clinically relevant CIN. Cutoff values for serum creatinine and estimated glomerular filtration rate (eGFR) beyond which iodinated contrast material would not be administered vary by institution, though eGFR is recognized to be a better indicator of baseline renal function than serum creatinine. Recent large studies from Davenport et al in 2013 and McDonald et al in 2014 indicate that intravenous iodinated contrast material is not an independent nephrotoxic risk factor in patients with a stable baseline eGFR of >45 mL/min/1.73 m2 and that iodinated contrast material is rarely nephrotoxic in patients with a stable baseline eGFR of 30 to 44 mL/min/1.73 m2 [60-63]. | Renovascular Hypertension. The selection of imaging modality and technique for evaluation of RAS may vary in the setting of decreased renal function primarily because of the risk of CIN with iodinated contrast material for CT and the risk of NSF with gadolinium-based contrast agents for MRI. US For patients with a high index of suspicion for renovascular disease and diminished renal function, duplex Doppler US is a preferred screening examination, especially at a site where the technique has proven to be reliable and where dedicated technologists and physicians are skilled in the examination and can perform it with a high degree of accuracy. The technical details of the examination and the threshold criteria are similar to those used for patients with normal renal function (see variant 1). CTA Depending on the degree of impaired renal function, contrast-enhanced CTA has been considered to be precluded because of potential nephrotoxicity of contrast material. However, the causal relationship between contrast material for CT and acute kidney injury has been disputed, and recent data suggest a low risk of clinically relevant CIN. Cutoff values for serum creatinine and estimated glomerular filtration rate (eGFR) beyond which iodinated contrast material would not be administered vary by institution, though eGFR is recognized to be a better indicator of baseline renal function than serum creatinine. Recent large studies from Davenport et al in 2013 and McDonald et al in 2014 indicate that intravenous iodinated contrast material is not an independent nephrotoxic risk factor in patients with a stable baseline eGFR of >45 mL/min/1.73 m2 and that iodinated contrast material is rarely nephrotoxic in patients with a stable baseline eGFR of 30 to 44 mL/min/1.73 m2 [60-63]. | 69374 |
acrac_69374_7 | Renovascular Hypertension | Conflicting results were obtained for patients with more severe renal dysfunction with an eGFR of <30 mL/min/1.73 m2, with the 2013 Davenport et al study reporting an excess of acute kidney injury in these patients receiving intravenous contrast material versus controls but with the 2014 McDonald et al study showing no significant difference in acute kidney injury for contrast material recipients versus control patients with this baseline eGFR [8,60-63]. The ACR Manual on Contrast Media notes that if a threshold for CIN risk is used, an eGFR of 30 mL/min/1.73 m2 has the greatest level of evidence [7]. Reduced iodine dose should be considered in patients with borderline renal function, but other parameters are similar to patients with normal renal function. Unenhanced CT does not provide useful diagnostic information regarding RAS. MRA Contrast-enhanced MRA may be precluded because of the risk of NSF with eGFR <30 mL/min/1.73 m2. In these patients, unenhanced MRA techniques are available as an alternative to contrast-enhanced MRA to avoid the risk of NSF. Utsunomiya et al [64], comparing unenhanced SSFP MRA with CT or IADSA in 26 patients, found a sensitivity, specificity, positive predictive value, and negative predictive value of 78%, 91%, 64%, and 96%, respectively. Mohrs et al [65], comparing an SSFP technique with contrast-enhanced MRA in 45 patients, found a sensitivity, specificity, positive predictive value, and negative predictive value of 75%, 99%, 75%, and 99%, respectively, for detecting renal artery stenoses >50%. Braidy et al [66] compared an unenhanced SSFP technique to contrast-enhanced MRA with a sensitivity, specificity, positive predictive value, and negative predictive value of 85%, 96%, 94%, and 96%, respectively, but emphasized that when stenosis is found, other modalities should be employed for better estimation. | Renovascular Hypertension. Conflicting results were obtained for patients with more severe renal dysfunction with an eGFR of <30 mL/min/1.73 m2, with the 2013 Davenport et al study reporting an excess of acute kidney injury in these patients receiving intravenous contrast material versus controls but with the 2014 McDonald et al study showing no significant difference in acute kidney injury for contrast material recipients versus control patients with this baseline eGFR [8,60-63]. The ACR Manual on Contrast Media notes that if a threshold for CIN risk is used, an eGFR of 30 mL/min/1.73 m2 has the greatest level of evidence [7]. Reduced iodine dose should be considered in patients with borderline renal function, but other parameters are similar to patients with normal renal function. Unenhanced CT does not provide useful diagnostic information regarding RAS. MRA Contrast-enhanced MRA may be precluded because of the risk of NSF with eGFR <30 mL/min/1.73 m2. In these patients, unenhanced MRA techniques are available as an alternative to contrast-enhanced MRA to avoid the risk of NSF. Utsunomiya et al [64], comparing unenhanced SSFP MRA with CT or IADSA in 26 patients, found a sensitivity, specificity, positive predictive value, and negative predictive value of 78%, 91%, 64%, and 96%, respectively. Mohrs et al [65], comparing an SSFP technique with contrast-enhanced MRA in 45 patients, found a sensitivity, specificity, positive predictive value, and negative predictive value of 75%, 99%, 75%, and 99%, respectively, for detecting renal artery stenoses >50%. Braidy et al [66] compared an unenhanced SSFP technique to contrast-enhanced MRA with a sensitivity, specificity, positive predictive value, and negative predictive value of 85%, 96%, 94%, and 96%, respectively, but emphasized that when stenosis is found, other modalities should be employed for better estimation. | 69374 |
acrac_3149013_0 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR aUniversity of California Los Angeles, Los Angeles, California. bPanel Chair, Montefiore Medical Center, Bronx, New York. cPanel Vice-Chair, Uniformed Services University, Bethesda, Maryland. dOhio State University, Columbus, Ohio. eMichigan State University, East Lansing, Michigan; American College of Emergency Physicians. fOttawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada; Canadian Association of Radiologists. gEmory University, Atlanta, Georgia. hBarrow Neurological Institute, Phoenix, Arizona; Neurosurgery expert. iMayo Clinic, Rochester, Minnesota. jUniversity of New Mexico, Albuquerque, New Mexico; American College of Physicians. kEinstein Healthcare Network, Philadelphia, Pennsylvania. lUniversity of California San Diego Medical Center, San Diego, California. mOregon Health & Science University, Portland, Oregon. nUniversity of North Carolina School of Medicine, Chapel Hill, North Carolina; American Academy of Neurology. oAlbany ENT & Allergy Services, PC, Albany, New York; American Academy of Otolaryngology-Head and Neck Surgery. pAlbert Einstein College of Medicine Montefiore Medical Center, Bronx, New York, Internal medicine physician. qColumbia University Medical Center, New York, New York. rUniversity of Cincinnati Medical Center, Cincinnati, Ohio. sSpecialty Chair, Atlanta VA Health Care System and Emory University, Atlanta, Georgia. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR aUniversity of California Los Angeles, Los Angeles, California. bPanel Chair, Montefiore Medical Center, Bronx, New York. cPanel Vice-Chair, Uniformed Services University, Bethesda, Maryland. dOhio State University, Columbus, Ohio. eMichigan State University, East Lansing, Michigan; American College of Emergency Physicians. fOttawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada; Canadian Association of Radiologists. gEmory University, Atlanta, Georgia. hBarrow Neurological Institute, Phoenix, Arizona; Neurosurgery expert. iMayo Clinic, Rochester, Minnesota. jUniversity of New Mexico, Albuquerque, New Mexico; American College of Physicians. kEinstein Healthcare Network, Philadelphia, Pennsylvania. lUniversity of California San Diego Medical Center, San Diego, California. mOregon Health & Science University, Portland, Oregon. nUniversity of North Carolina School of Medicine, Chapel Hill, North Carolina; American Academy of Neurology. oAlbany ENT & Allergy Services, PC, Albany, New York; American Academy of Otolaryngology-Head and Neck Surgery. pAlbert Einstein College of Medicine Montefiore Medical Center, Bronx, New York, Internal medicine physician. qColumbia University Medical Center, New York, New York. rUniversity of Cincinnati Medical Center, Cincinnati, Ohio. sSpecialty Chair, Atlanta VA Health Care System and Emory University, Atlanta, Georgia. | 3149013 |
acrac_3149013_1 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] This variant will focus on imaging examinations used to determine the source of SAH after initial detection. SAH, involving the basal cisterns, requires rapid triage and workup because a ruptured cerebral aneurysm is responsible for 70% of all nontraumatic SAHs [4,5]. The overall incidence of aneurysmal SAH in the United States is between 9.7 and 14.5 cases per 100,000 population and may be underestimated due to the high risk of death prior to hospital admission [6-9]. Aneurysmal SAH results in significant morbidity and mortality with a quarter of aneurysmal subarachnoid patients dying after presentation; therefore, early diagnosis and repair is crucial to prevent rebleeding [6]. Less common causes of SAH, often presenting as isolated convexity SAH, such as tumors, stroke transformation, cerebral amyloid angiopathy, or reversible cerebral vasoconstriction syndrome, are not considered here as their imaging and diagnosis often follows the initial, commonly emergent, imaging revaluation for common vascular lesions. Follow-up imaging for delayed complications of SAH, such as hydrocephalus, should be directed by local protocols and clinical symptoms. The delayed complication of vasospasm after SAH is discussed in Variant 2 of this topic. Arteriography Cervicocerebral Catheter-directed angiography of the cerebral vasculature demonstrates high spatial resolution, large field of view, and dynamic acquisition that leads to high diagnostic value in the evaluation of cerebrovascular diseases resulting in SAH. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] This variant will focus on imaging examinations used to determine the source of SAH after initial detection. SAH, involving the basal cisterns, requires rapid triage and workup because a ruptured cerebral aneurysm is responsible for 70% of all nontraumatic SAHs [4,5]. The overall incidence of aneurysmal SAH in the United States is between 9.7 and 14.5 cases per 100,000 population and may be underestimated due to the high risk of death prior to hospital admission [6-9]. Aneurysmal SAH results in significant morbidity and mortality with a quarter of aneurysmal subarachnoid patients dying after presentation; therefore, early diagnosis and repair is crucial to prevent rebleeding [6]. Less common causes of SAH, often presenting as isolated convexity SAH, such as tumors, stroke transformation, cerebral amyloid angiopathy, or reversible cerebral vasoconstriction syndrome, are not considered here as their imaging and diagnosis often follows the initial, commonly emergent, imaging revaluation for common vascular lesions. Follow-up imaging for delayed complications of SAH, such as hydrocephalus, should be directed by local protocols and clinical symptoms. The delayed complication of vasospasm after SAH is discussed in Variant 2 of this topic. Arteriography Cervicocerebral Catheter-directed angiography of the cerebral vasculature demonstrates high spatial resolution, large field of view, and dynamic acquisition that leads to high diagnostic value in the evaluation of cerebrovascular diseases resulting in SAH. | 3149013 |
acrac_3149013_2 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Sensitivity and specificity are both >98% for catheter cerebral angiography when compared with surgical findings, including small aneurysms <3 mm [10]. Catheter cerebral angiography also identified vascular abnormalities in up to 13% of patients with SAH and negative CTA imaging [11]. Although catheter cerebral angiography has been reported to be negative in 2% to 24% of patients with aneurysmal SAH, 3-D rotational angiography has been shown to identify an aneurysm on 25% of previously angiogram, both 2-D and 3-D, negative patients [12]. Angiography is an invasive procedure with a small complication risk related to intravascular instrumentation. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the evaluation of known acute SAH. CTA Head CTA head is a fast, noninvasive study to evaluate patients with acute SAH. CTA head has been shown to have >90% sensitivity and specificity in the evaluation for aneurysms [4,10,13-18] responsible for SAHs. However, CTA head sensitivity for detecting aneurysm decreases for aneurysms <3 mm in size [4,10,13,15,17,19], in the setting of diffuse SAH [20], and for aneurysms occurring adjacent to an osseous structure [19]. CTA head may be sufficient to rule out a vascular cause of SAH when the location of hemorrhage is isolated to the perimesencephalic region with follow-up catheter-directed angiography indicated in CTA negative diffuse or peripheral SAHs [20]. CTA Neck There is no relevant literature to support the use of CTA neck in the initial imaging evaluation of known acute SAH. CTA neck may be useful for potential treatment planning, but preference will be individual or site specific. CTV Head There is no relevant literature to support the use of CT venography (CTV) head in the evaluation of known acute SAH. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Sensitivity and specificity are both >98% for catheter cerebral angiography when compared with surgical findings, including small aneurysms <3 mm [10]. Catheter cerebral angiography also identified vascular abnormalities in up to 13% of patients with SAH and negative CTA imaging [11]. Although catheter cerebral angiography has been reported to be negative in 2% to 24% of patients with aneurysmal SAH, 3-D rotational angiography has been shown to identify an aneurysm on 25% of previously angiogram, both 2-D and 3-D, negative patients [12]. Angiography is an invasive procedure with a small complication risk related to intravascular instrumentation. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the evaluation of known acute SAH. CTA Head CTA head is a fast, noninvasive study to evaluate patients with acute SAH. CTA head has been shown to have >90% sensitivity and specificity in the evaluation for aneurysms [4,10,13-18] responsible for SAHs. However, CTA head sensitivity for detecting aneurysm decreases for aneurysms <3 mm in size [4,10,13,15,17,19], in the setting of diffuse SAH [20], and for aneurysms occurring adjacent to an osseous structure [19]. CTA head may be sufficient to rule out a vascular cause of SAH when the location of hemorrhage is isolated to the perimesencephalic region with follow-up catheter-directed angiography indicated in CTA negative diffuse or peripheral SAHs [20]. CTA Neck There is no relevant literature to support the use of CTA neck in the initial imaging evaluation of known acute SAH. CTA neck may be useful for potential treatment planning, but preference will be individual or site specific. CTV Head There is no relevant literature to support the use of CT venography (CTV) head in the evaluation of known acute SAH. | 3149013 |
acrac_3149013_3 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | CVD-Aneurysm, Vascular Malformation, and SAH MRA Head MR angiography (MRA) head for the evaluation of intracranial aneurysm demonstrated a pooled sensitivity of 95% and specificity of 89% in one meta-analysis [21]. Diagnostic accuracy is increased, including for aneurysms >5 mm in size and at 3T scanner strength [21,22]. The decrease in specificity, when compared with CTA, is reported to have false-positive cases related to normal vascular variants of infundibular origin of vessels and vessel loops [23]. Limitations of MRA head include required safety screening and relatively long acquisition time in urgent clinical scenarios. MRA Neck There is no relevant literature to support the use of MRA neck in the evaluation of known acute SAH. MRA neck may be useful for potential treatment planning, but preference will be individual or site specific. MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the evaluation of known acute SAH. MRI Head Although there is no relevant literature to support the use of MRI head in the evaluation for a vascular source of known acute SAH, several studies evaluated the use of MRI head in predicting clinical outcomes. Patients with acute poor-grade SAH and diffusion-weighted imaging positive findings on MRI head had a less favorable long- term outcome when compared with patients without diffusion-weighted imaging positive findings [24,25]. MRV Head There is no relevant literature to support the use of MR venography (MRV) head in the evaluation of known acute SAH. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery ultrasound (US) duplex Doppler in the evaluation of known acute SAH. US Duplex Doppler Transcranial There is no relevant literature to support the use of US transcranial with duplex Doppler (TCD) in the evaluation of known acute SAH. Variant 2: Suspected cerebral vasospasm. Initial imaging. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. CVD-Aneurysm, Vascular Malformation, and SAH MRA Head MR angiography (MRA) head for the evaluation of intracranial aneurysm demonstrated a pooled sensitivity of 95% and specificity of 89% in one meta-analysis [21]. Diagnostic accuracy is increased, including for aneurysms >5 mm in size and at 3T scanner strength [21,22]. The decrease in specificity, when compared with CTA, is reported to have false-positive cases related to normal vascular variants of infundibular origin of vessels and vessel loops [23]. Limitations of MRA head include required safety screening and relatively long acquisition time in urgent clinical scenarios. MRA Neck There is no relevant literature to support the use of MRA neck in the evaluation of known acute SAH. MRA neck may be useful for potential treatment planning, but preference will be individual or site specific. MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the evaluation of known acute SAH. MRI Head Although there is no relevant literature to support the use of MRI head in the evaluation for a vascular source of known acute SAH, several studies evaluated the use of MRI head in predicting clinical outcomes. Patients with acute poor-grade SAH and diffusion-weighted imaging positive findings on MRI head had a less favorable long- term outcome when compared with patients without diffusion-weighted imaging positive findings [24,25]. MRV Head There is no relevant literature to support the use of MR venography (MRV) head in the evaluation of known acute SAH. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery ultrasound (US) duplex Doppler in the evaluation of known acute SAH. US Duplex Doppler Transcranial There is no relevant literature to support the use of US transcranial with duplex Doppler (TCD) in the evaluation of known acute SAH. Variant 2: Suspected cerebral vasospasm. Initial imaging. | 3149013 |
acrac_3149013_4 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Vasospasm in the cerebral arteries occurs in approximately 30% of patients with SAH and frequently occurs 7 to 10 days after hemorrhage with spontaneous resolution by day 21 [6]. Vasospasm is associated with delayed cerebral ischemia defined by delayed development of neurologic deficits after SAH not related to aneurysm treatment or other neurologic complications, such as hydrocephalus, cerebral edema, or metabolic derangements [26]. Morbidity and mortality in SAH increases between 10% and 20% after onset of clinical symptoms of delayed cerebral ischemia [27], and the symptoms are frequently nonreversible [28,29]. Imaging findings of vasospasm and guidance of treatment does not appear to improve clinical outcome after the onset of clinical symptoms [28]. Despite the association of moderate to severe vasospasm and poor clinical outcome [30], only 50% patients with large-vessel vasospasm develop clinical ischemic neurologic symptoms [6], and delayed ischemia can occur in the absence of imaging findings of vasospasm [26]. However, given the clinical implications of delayed cerebral ischemia, early screening and detection of vasospasm remains recommended [6]. Arteriography Cervicocerebral Conventional catheter-directed cerebrovascular arteriography is the reference standard for characterization of intracranial vasospasm. However, only approximately 50% of radiographic large-vessel vasospasm develops delayed cerebral ischemia, and given the invasive nature and potential rare neurologic complications, other less invasive screening methods are often performed before catheter angiogram [28]. In a large, international multicenter randomized trial, the presence of angiographic vasospasm was strongly associated (odds ratio of 9.3) with the development of cerebral infarction. In the same study, a small number of patients (3%) developed infarction without evidence of vasospasm on angiogram [31]. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Vasospasm in the cerebral arteries occurs in approximately 30% of patients with SAH and frequently occurs 7 to 10 days after hemorrhage with spontaneous resolution by day 21 [6]. Vasospasm is associated with delayed cerebral ischemia defined by delayed development of neurologic deficits after SAH not related to aneurysm treatment or other neurologic complications, such as hydrocephalus, cerebral edema, or metabolic derangements [26]. Morbidity and mortality in SAH increases between 10% and 20% after onset of clinical symptoms of delayed cerebral ischemia [27], and the symptoms are frequently nonreversible [28,29]. Imaging findings of vasospasm and guidance of treatment does not appear to improve clinical outcome after the onset of clinical symptoms [28]. Despite the association of moderate to severe vasospasm and poor clinical outcome [30], only 50% patients with large-vessel vasospasm develop clinical ischemic neurologic symptoms [6], and delayed ischemia can occur in the absence of imaging findings of vasospasm [26]. However, given the clinical implications of delayed cerebral ischemia, early screening and detection of vasospasm remains recommended [6]. Arteriography Cervicocerebral Conventional catheter-directed cerebrovascular arteriography is the reference standard for characterization of intracranial vasospasm. However, only approximately 50% of radiographic large-vessel vasospasm develops delayed cerebral ischemia, and given the invasive nature and potential rare neurologic complications, other less invasive screening methods are often performed before catheter angiogram [28]. In a large, international multicenter randomized trial, the presence of angiographic vasospasm was strongly associated (odds ratio of 9.3) with the development of cerebral infarction. In the same study, a small number of patients (3%) developed infarction without evidence of vasospasm on angiogram [31]. | 3149013 |
acrac_3149013_5 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | An additional consideration to the angiographic evaluation of vasospasm is the potential for intra-arterial treatment of vessel narrowing. However, intra-arterial treatment of vasospasm lacks high-quality evidence of improvement of outcomes at this time [6]. CT Head SAH on CT head can be graded by the Fisher or modified Fisher scale. The higher the Fisher grade of SAH, the higher the patient risk for vasospasm [35]. Although CT head may be useful to provide a Fisher grade and risk for vasospasm, the examination does not directly give information regarding the presence or absence of vasospasm. Anatomic changes of completed infarct related to delayed cerebral ischemia can also be identified on CT head. CTA Head CTA head can provide a less invasive evaluation of the intracranial cerebral vasculature compared with catheter- directed angiography. In a meta-analysis, CTA head detected vasospasm with a sensitivity and specificity of 80% and 93%, respectively [33]. CTA head is highly correlated to conventional angiography for larger proximal intracranial vessels with decreasing correlation in the smaller more distal arteries [36]. CTA Neck There is no relevant literature to support the use of CTA neck in the evaluation of suspected cerebral vasospasm. CTV Head There is no relevant literature to support the use of CTV head in the evaluation of suspected cerebral vasospasm. MRA Head There is no relevant literature to support the use of MRA head in the evaluation of suspected cerebral vasospasm. MRA head evaluation of the intracranial arteries in the setting of suspected vasospasm is limited by background of hemorrhage and hemodynamic flow alterations with poor correlation to digital subtraction angiography (DSA) findings [37]. MRA Neck There is no relevant literature to support the use of MRA neck in the evaluation of suspected cerebral vasospasm. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. An additional consideration to the angiographic evaluation of vasospasm is the potential for intra-arterial treatment of vessel narrowing. However, intra-arterial treatment of vasospasm lacks high-quality evidence of improvement of outcomes at this time [6]. CT Head SAH on CT head can be graded by the Fisher or modified Fisher scale. The higher the Fisher grade of SAH, the higher the patient risk for vasospasm [35]. Although CT head may be useful to provide a Fisher grade and risk for vasospasm, the examination does not directly give information regarding the presence or absence of vasospasm. Anatomic changes of completed infarct related to delayed cerebral ischemia can also be identified on CT head. CTA Head CTA head can provide a less invasive evaluation of the intracranial cerebral vasculature compared with catheter- directed angiography. In a meta-analysis, CTA head detected vasospasm with a sensitivity and specificity of 80% and 93%, respectively [33]. CTA head is highly correlated to conventional angiography for larger proximal intracranial vessels with decreasing correlation in the smaller more distal arteries [36]. CTA Neck There is no relevant literature to support the use of CTA neck in the evaluation of suspected cerebral vasospasm. CTV Head There is no relevant literature to support the use of CTV head in the evaluation of suspected cerebral vasospasm. MRA Head There is no relevant literature to support the use of MRA head in the evaluation of suspected cerebral vasospasm. MRA head evaluation of the intracranial arteries in the setting of suspected vasospasm is limited by background of hemorrhage and hemodynamic flow alterations with poor correlation to digital subtraction angiography (DSA) findings [37]. MRA Neck There is no relevant literature to support the use of MRA neck in the evaluation of suspected cerebral vasospasm. | 3149013 |
acrac_3149013_6 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | MRI Head Perfusion Given the continued difficulty in identifying patients at risk for and in preventing vasospasm and delayed cerebral ischemia, advanced MRI head perfusion studies are now being performed. MRI head perfusion with decreased intravoxel incoherent motion microvascular perfusion has been associated with vasospasm [38], and elevated blood- brain barrier permeability (Ktrans) was associated with patients who went on to develop delayed cerebral ischemia [39]. Despite these early positive studies, no large or prospective studies have been performed to support the widespread use of MRI head perfusion in the evaluation of suspected vasospasm. MRI Head MRI head offers evaluation of consequences of delayed cerebral ischemia including completed infarction. However, there is no relevant literature to support the use of MRI head in the evaluation of suspected cerebral vasospasm. MRV Head There is no relevant literature to support the use of MRV head in the evaluation of suspected cerebral vasospasm. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the evaluation of suspected cerebral vasospasm. CVD-Aneurysm, Vascular Malformation, and SAH US Duplex Doppler Transcranial TCD is a quick and noninvasive modality to evaluate for increased arterial velocities in the setting of vasospasm. Given the ability to perform the examination at the bedside, daily TCD is frequently used in the screening for vasospasm in at-risk populations. Vasospasm identified on TCD predicts delayed cerebral ischemia with 90% sensitivity, 92% negative predictive value, 71% specificity, and 57% positive predictive value [40]. Although screening for vasospasm with TCD has high sensitivity and negative predictive value, prolonged TCD screening past day 10 post-SAH does not appear to increase detection of delayed cerebral ischemia [41]. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. MRI Head Perfusion Given the continued difficulty in identifying patients at risk for and in preventing vasospasm and delayed cerebral ischemia, advanced MRI head perfusion studies are now being performed. MRI head perfusion with decreased intravoxel incoherent motion microvascular perfusion has been associated with vasospasm [38], and elevated blood- brain barrier permeability (Ktrans) was associated with patients who went on to develop delayed cerebral ischemia [39]. Despite these early positive studies, no large or prospective studies have been performed to support the widespread use of MRI head perfusion in the evaluation of suspected vasospasm. MRI Head MRI head offers evaluation of consequences of delayed cerebral ischemia including completed infarction. However, there is no relevant literature to support the use of MRI head in the evaluation of suspected cerebral vasospasm. MRV Head There is no relevant literature to support the use of MRV head in the evaluation of suspected cerebral vasospasm. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the evaluation of suspected cerebral vasospasm. CVD-Aneurysm, Vascular Malformation, and SAH US Duplex Doppler Transcranial TCD is a quick and noninvasive modality to evaluate for increased arterial velocities in the setting of vasospasm. Given the ability to perform the examination at the bedside, daily TCD is frequently used in the screening for vasospasm in at-risk populations. Vasospasm identified on TCD predicts delayed cerebral ischemia with 90% sensitivity, 92% negative predictive value, 71% specificity, and 57% positive predictive value [40]. Although screening for vasospasm with TCD has high sensitivity and negative predictive value, prolonged TCD screening past day 10 post-SAH does not appear to increase detection of delayed cerebral ischemia [41]. | 3149013 |
acrac_3149013_7 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | In addition, there is no current high-quality literature relating detection of vasospasm on TCD to improved patient outcomes [40]. Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring. Cerebral aneurysms are often incidentally discovered on intracranial vascular imaging. Definitive algorithmic guidelines for management and follow-up of incidentally found cerebral aneurysms are lacking [42]. Between 4% and 18% of aneurysms demonstrate growth on imaging follow-up [43,44], with a 12-fold higher risk of rupture in growing aneurysms [44]. Although aneurysm growth is associated with size >7 mm, smaller aneurysms can grow and rupture [44]. Given the evidence of potential for growth and rupture of untreated and unruptured aneurysms, vascular imaging surveillance is recommended. Arteriography Cervicocerebral Cervicocerebral arteriography remains the reference standard imaging examination for the evaluation of cerebral aneurysms with high spatial resolution, high signal-to-noise ratio, and dynamic image acquisition. However, given the invasive nature and potential complications of cervicocerebral arteriography, it is not ideal for routine patient surveillance. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the surveillance of a known, untreated cerebral aneurysm. CT Head There is no relevant literature to support the use of CT head in the surveillance of a known, untreated cerebral aneurysm. CTA Head CTA head is a fast and noninvasive study to evaluate the intracranial vasculature. CTA head has been shown to be >90% sensitive and specific in the evaluation for aneurysms [4,10,13-18]. However, CTA head sensitivity for detecting an aneurysm decreases for aneurysms <3 mm in size [4,10,13,15,17,19] and for aneurysms occurring adjacent to an osseous structure [19]. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. In addition, there is no current high-quality literature relating detection of vasospasm on TCD to improved patient outcomes [40]. Variant 3: Known cerebral aneurysm; untreated. Surveillance monitoring. Cerebral aneurysms are often incidentally discovered on intracranial vascular imaging. Definitive algorithmic guidelines for management and follow-up of incidentally found cerebral aneurysms are lacking [42]. Between 4% and 18% of aneurysms demonstrate growth on imaging follow-up [43,44], with a 12-fold higher risk of rupture in growing aneurysms [44]. Although aneurysm growth is associated with size >7 mm, smaller aneurysms can grow and rupture [44]. Given the evidence of potential for growth and rupture of untreated and unruptured aneurysms, vascular imaging surveillance is recommended. Arteriography Cervicocerebral Cervicocerebral arteriography remains the reference standard imaging examination for the evaluation of cerebral aneurysms with high spatial resolution, high signal-to-noise ratio, and dynamic image acquisition. However, given the invasive nature and potential complications of cervicocerebral arteriography, it is not ideal for routine patient surveillance. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the surveillance of a known, untreated cerebral aneurysm. CT Head There is no relevant literature to support the use of CT head in the surveillance of a known, untreated cerebral aneurysm. CTA Head CTA head is a fast and noninvasive study to evaluate the intracranial vasculature. CTA head has been shown to be >90% sensitive and specific in the evaluation for aneurysms [4,10,13-18]. However, CTA head sensitivity for detecting an aneurysm decreases for aneurysms <3 mm in size [4,10,13,15,17,19] and for aneurysms occurring adjacent to an osseous structure [19]. | 3149013 |
acrac_3149013_8 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | CTA Neck There is no relevant literature to support the use of CTA neck in the surveillance of a known, untreated cerebral aneurysm. CTV Head There is no relevant literature to support the use of CTV head in the surveillance of a known, untreated cerebral aneurysm. MRA Head MRA head is an ideal candidate for imaging surveillance of known, untreated aneurysms because of its noninvasive nature and ability to obtain diagnostic information without intravenous (IV) contrast. The evaluation of intracranial aneurysm with MRA head demonstrated a pooled sensitivity of 95% and specificity of 89% in one meta-analysis [21]. Diagnostic accuracy is increased, including for aneurysms <5 mm in size, at 3T scanner strength [21,22]. Vessel loops and infundibular origins of vessels can lead to false-positives for aneurysm on MRA [23]. Contrast- enhanced MRA head may increase visualized detail of large aneurysms with complex flow dynamics or thrombosis [45]. However, there is no significant difference in diagnostic performance between time-of-flight MRA and contrast-enhanced MRA on the aforementioned meta-analysis of MRA examinations in the diagnosis of aneurysms [21]. MRA Neck There is no relevant literature to support the use of MRA neck in the surveillance of a known, untreated cerebral aneurysm. CVD-Aneurysm, Vascular Malformation, and SAH MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the surveillance of a known, untreated cerebral aneurysm. MRI Head There is no relevant literature to support the use of MRI head in the surveillance of a known, untreated cerebral aneurysm. MRV Head There is no relevant literature to support the use of MRV head in the surveillance of a known, untreated cerebral aneurysm. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the surveillance of a known, untreated cerebral aneurysm. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. CTA Neck There is no relevant literature to support the use of CTA neck in the surveillance of a known, untreated cerebral aneurysm. CTV Head There is no relevant literature to support the use of CTV head in the surveillance of a known, untreated cerebral aneurysm. MRA Head MRA head is an ideal candidate for imaging surveillance of known, untreated aneurysms because of its noninvasive nature and ability to obtain diagnostic information without intravenous (IV) contrast. The evaluation of intracranial aneurysm with MRA head demonstrated a pooled sensitivity of 95% and specificity of 89% in one meta-analysis [21]. Diagnostic accuracy is increased, including for aneurysms <5 mm in size, at 3T scanner strength [21,22]. Vessel loops and infundibular origins of vessels can lead to false-positives for aneurysm on MRA [23]. Contrast- enhanced MRA head may increase visualized detail of large aneurysms with complex flow dynamics or thrombosis [45]. However, there is no significant difference in diagnostic performance between time-of-flight MRA and contrast-enhanced MRA on the aforementioned meta-analysis of MRA examinations in the diagnosis of aneurysms [21]. MRA Neck There is no relevant literature to support the use of MRA neck in the surveillance of a known, untreated cerebral aneurysm. CVD-Aneurysm, Vascular Malformation, and SAH MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the surveillance of a known, untreated cerebral aneurysm. MRI Head There is no relevant literature to support the use of MRI head in the surveillance of a known, untreated cerebral aneurysm. MRV Head There is no relevant literature to support the use of MRV head in the surveillance of a known, untreated cerebral aneurysm. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the surveillance of a known, untreated cerebral aneurysm. | 3149013 |
acrac_3149013_9 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the surveillance of a known, untreated cerebral aneurysm. Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring. Treatment of cerebral aneurysms is common to reduce the risk of aneurysm rupture or rebleeding. Endovascular treatment is now the first-line therapy in most cases, whereas aneurysms not amenable to endovascular repair require surgical clipping or observation. Follow-up imaging after treatment is often performed to assess for potential refilling of aneurysms and detect formation of new aneurysms. Aneurysm remnants after surgical clipping are identified in up to 11% of patients [46] and more frequently after endovascular repair [47,48]. Recurrence of treated aneurysm is most common within 6 months of treatment but can occur in a more delayed manner [49]. Development of de novo aneurysm occurs in 1% to 8% of patients with treated aneurysms [50-52]. Imaging evaluation is focused on not only the treated aneurysm but also the integrity of the parent vessel and formation of new aneurysms. Intracranial aneurysms are treated with several different devices, including surgical clips, detachable coils, stents, and flow diverters, and each device will result in unique appearances as well as challenges, depending on the imaging modality used. Specific knowledge of the technique utilized in prior treatment is helpful in choosing a particular follow-up modality for each patient. Arteriography Cervicocerebral Cervicocerebral arteriography remains the reference standard imaging examination for the evaluation of treated cerebral aneurysms with high spatial resolution, high signal-to-noise ratio, and dynamic image acquisition. Aneurysm and parent vessel appearance is better visualized, as indwelling occlusion device artifacts are less apparent on cervicocerebral arteriography than on MRI or CT. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the surveillance of a known, untreated cerebral aneurysm. Variant 4: Known cerebral aneurysm; previously treated. Surveillance monitoring. Treatment of cerebral aneurysms is common to reduce the risk of aneurysm rupture or rebleeding. Endovascular treatment is now the first-line therapy in most cases, whereas aneurysms not amenable to endovascular repair require surgical clipping or observation. Follow-up imaging after treatment is often performed to assess for potential refilling of aneurysms and detect formation of new aneurysms. Aneurysm remnants after surgical clipping are identified in up to 11% of patients [46] and more frequently after endovascular repair [47,48]. Recurrence of treated aneurysm is most common within 6 months of treatment but can occur in a more delayed manner [49]. Development of de novo aneurysm occurs in 1% to 8% of patients with treated aneurysms [50-52]. Imaging evaluation is focused on not only the treated aneurysm but also the integrity of the parent vessel and formation of new aneurysms. Intracranial aneurysms are treated with several different devices, including surgical clips, detachable coils, stents, and flow diverters, and each device will result in unique appearances as well as challenges, depending on the imaging modality used. Specific knowledge of the technique utilized in prior treatment is helpful in choosing a particular follow-up modality for each patient. Arteriography Cervicocerebral Cervicocerebral arteriography remains the reference standard imaging examination for the evaluation of treated cerebral aneurysms with high spatial resolution, high signal-to-noise ratio, and dynamic image acquisition. Aneurysm and parent vessel appearance is better visualized, as indwelling occlusion device artifacts are less apparent on cervicocerebral arteriography than on MRI or CT. | 3149013 |
acrac_3149013_10 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Drawbacks for surveillance include invasiveness and small risk of vascular complication. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the surveillance of known, treated cerebral aneurysm. CT Head There is no relevant literature to support the use of CT head in the surveillance of known, treated cerebral aneurysm. CTA Head CTA head is useful for surveillance imaging of treated cerebral aneurysms because of its noninvasive nature. However, CTA is limited by large metallic streak artifacts encountered with metallic coils, stents, and devices. Although artifact from metal cannot be removed, several metal artifact reduction techniques are available to improve evaluation of treated aneurysms and the parent vessels [53-57]. CTA Neck There is no relevant literature to support the use of CTA neck in the surveillance of known, treated cerebral aneurysm. CTV Head There is no relevant literature to support the use of CTV head in the surveillance of known, treated cerebral aneurysm. CVD-Aneurysm, Vascular Malformation, and SAH MRA Head MRA head is a noninvasive examination commonly used for treated aneurysm surveillance. This examination can be obtained without IV contrast using time-of-flight imaging, with IV contrast to improve flow-related artifacts occasionally encountered in aneurysms, or a combination of both. In the setting of coiled aneurysms, a meta-analysis found similar performance of both noncontrast and contrast-enhanced examinations with sensitivities of 86% for both time-of-flight and contrast-enhanced MRA, as well as specificities of 84% and 89%, respectively [58]. MRA head was also compared directly with catheter-directed angiography and found to result in substantial agreement (kappa 0.73) regarding treatment recommendations between the 2 examinations [59]. Treatment with stents or flow diverters results in challenges in MRA intraluminal evaluation of the stent. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Drawbacks for surveillance include invasiveness and small risk of vascular complication. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the surveillance of known, treated cerebral aneurysm. CT Head There is no relevant literature to support the use of CT head in the surveillance of known, treated cerebral aneurysm. CTA Head CTA head is useful for surveillance imaging of treated cerebral aneurysms because of its noninvasive nature. However, CTA is limited by large metallic streak artifacts encountered with metallic coils, stents, and devices. Although artifact from metal cannot be removed, several metal artifact reduction techniques are available to improve evaluation of treated aneurysms and the parent vessels [53-57]. CTA Neck There is no relevant literature to support the use of CTA neck in the surveillance of known, treated cerebral aneurysm. CTV Head There is no relevant literature to support the use of CTV head in the surveillance of known, treated cerebral aneurysm. CVD-Aneurysm, Vascular Malformation, and SAH MRA Head MRA head is a noninvasive examination commonly used for treated aneurysm surveillance. This examination can be obtained without IV contrast using time-of-flight imaging, with IV contrast to improve flow-related artifacts occasionally encountered in aneurysms, or a combination of both. In the setting of coiled aneurysms, a meta-analysis found similar performance of both noncontrast and contrast-enhanced examinations with sensitivities of 86% for both time-of-flight and contrast-enhanced MRA, as well as specificities of 84% and 89%, respectively [58]. MRA head was also compared directly with catheter-directed angiography and found to result in substantial agreement (kappa 0.73) regarding treatment recommendations between the 2 examinations [59]. Treatment with stents or flow diverters results in challenges in MRA intraluminal evaluation of the stent. | 3149013 |
acrac_3149013_11 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Contrast-enhanced MRA outperforms time-of-flight MRA in the evaluation of a treated aneurysm and parent vessel patency with indwelling stent; however, intraluminal detail is limited with both techniques [60]. Newer endovascular devices demonstrate magnetic susceptibility and Faraday cage effects, which limits MRA head utility in assessing for aneurysm thrombosis or parent vessel patency when compared with conventional arteriography [61-63]. MRA Neck There is no relevant literature to support the use of MRA neck in the surveillance of known, treated cerebral aneurysm. MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the surveillance of known, treated cerebral aneurysm. MRI Head There is no relevant literature to support the use of MRI head in the surveillance of known, treated cerebral aneurysm. MRV Head There is no relevant literature to support the use of MRV head in the surveillance of known, treated cerebral aneurysm. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the surveillance of known, treated cerebral aneurysm. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the surveillance of known, treated cerebral aneurysm. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the screening of patients at high risk for cerebral aneurysm. CVD-Aneurysm, Vascular Malformation, and SAH CT Head There is no relevant literature to support the use of CT head in the screening of patients at high risk for cerebral aneurysm. CTA Head CTA head is a fast, noninvasive study to evaluate the intracranial vasculature. CTA head has been shown to be >90% sensitive and specific in the evaluation for aneurysms [4,10,13-18]. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Contrast-enhanced MRA outperforms time-of-flight MRA in the evaluation of a treated aneurysm and parent vessel patency with indwelling stent; however, intraluminal detail is limited with both techniques [60]. Newer endovascular devices demonstrate magnetic susceptibility and Faraday cage effects, which limits MRA head utility in assessing for aneurysm thrombosis or parent vessel patency when compared with conventional arteriography [61-63]. MRA Neck There is no relevant literature to support the use of MRA neck in the surveillance of known, treated cerebral aneurysm. MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the surveillance of known, treated cerebral aneurysm. MRI Head There is no relevant literature to support the use of MRI head in the surveillance of known, treated cerebral aneurysm. MRV Head There is no relevant literature to support the use of MRV head in the surveillance of known, treated cerebral aneurysm. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the surveillance of known, treated cerebral aneurysm. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the surveillance of known, treated cerebral aneurysm. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the screening of patients at high risk for cerebral aneurysm. CVD-Aneurysm, Vascular Malformation, and SAH CT Head There is no relevant literature to support the use of CT head in the screening of patients at high risk for cerebral aneurysm. CTA Head CTA head is a fast, noninvasive study to evaluate the intracranial vasculature. CTA head has been shown to be >90% sensitive and specific in the evaluation for aneurysms [4,10,13-18]. | 3149013 |
acrac_3149013_12 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | However, CTA head sensitivity for detecting an aneurysm decreases for both aneurysms <3 mm in size [4,10,13,15,17,19] and aneurysms occurring adjacent to an osseous structure [19]. CTA Neck There is no relevant literature to support the use of CTA neck in the screening of patients at high risk for cerebral aneurysm. CTV Head There is no relevant literature to support the use of CTV head in the screening of patients at high risk for cerebral aneurysm. MRA Head MRA head is an ideal candidate for screening high-risk populations for cerebral aneurysm due to its noninvasive nature and ability to obtain diagnostic information without IV contrast. The evaluation of intracranial aneurysm with MRA head demonstrated a pooled sensitivity of 95% and specificity of 89% in one meta-analysis, in which 45% of the 67 missed aneurysms were <3 mm in size, and another 45% were between 3 and 5 mm in size, 6% were between 5 and 10 mm in size, and 4% >10 mm in size [21]. Diagnostic accuracy is increased, including for aneurysms <5 mm in size, at 3T scanner strength [21,22]. Vessel loops and infundibular origins of vessels can lead to false-positives for aneurysm on MRA [23]. Contrast-enhanced MRA head has no relevant literature to support its use in the screening of patients at high risk for cerebral aneurysm. MRA Neck There is no relevant literature to support the use of MRA neck in the screening of patients at high risk for cerebral aneurysm. MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the screening of patients at high risk for cerebral aneurysm. MRI Head There is no relevant literature to support the use of MRI head in the screening of patients at high risk for cerebral aneurysm. MRV Head There is no relevant literature to support the use of MRV head in the screening of patients at high risk for cerebral aneurysm. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. However, CTA head sensitivity for detecting an aneurysm decreases for both aneurysms <3 mm in size [4,10,13,15,17,19] and aneurysms occurring adjacent to an osseous structure [19]. CTA Neck There is no relevant literature to support the use of CTA neck in the screening of patients at high risk for cerebral aneurysm. CTV Head There is no relevant literature to support the use of CTV head in the screening of patients at high risk for cerebral aneurysm. MRA Head MRA head is an ideal candidate for screening high-risk populations for cerebral aneurysm due to its noninvasive nature and ability to obtain diagnostic information without IV contrast. The evaluation of intracranial aneurysm with MRA head demonstrated a pooled sensitivity of 95% and specificity of 89% in one meta-analysis, in which 45% of the 67 missed aneurysms were <3 mm in size, and another 45% were between 3 and 5 mm in size, 6% were between 5 and 10 mm in size, and 4% >10 mm in size [21]. Diagnostic accuracy is increased, including for aneurysms <5 mm in size, at 3T scanner strength [21,22]. Vessel loops and infundibular origins of vessels can lead to false-positives for aneurysm on MRA [23]. Contrast-enhanced MRA head has no relevant literature to support its use in the screening of patients at high risk for cerebral aneurysm. MRA Neck There is no relevant literature to support the use of MRA neck in the screening of patients at high risk for cerebral aneurysm. MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the screening of patients at high risk for cerebral aneurysm. MRI Head There is no relevant literature to support the use of MRI head in the screening of patients at high risk for cerebral aneurysm. MRV Head There is no relevant literature to support the use of MRV head in the screening of patients at high risk for cerebral aneurysm. | 3149013 |
acrac_3149013_13 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the screening of patients at high risk for cerebral aneurysm. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the screening of patients at high risk for cerebral aneurysm. Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring. Intracranial high-flow vascular malformations include arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). Both lesions are defined by an abnormal connection between the relatively high-pressure arterial system and the low-pressure venous system resulting in a high-flow shunting of blood. AVMs are direct connections of artery to vein via abnormal dilated vascular channels without normal intermediary capillary bed. The abnormal dilated vascular channels are known as the nidus [74]. Although the true incidence of brain AVM is unknown, asymptomatic prevalence on MRI is estimated at 0.05% [74,75]. Between 10% and 20% of patients with hereditary hemorrhagic telangiectasia will have at least one AVM during their lifetime [74,76]. CVD-Aneurysm, Vascular Malformation, and SAH Symptomatic brain AVMs present most commonly with hemorrhage or epilepsy [74]. The annual rupture risk of a brain AVM is 1.3% for previously unruptured AVM and up to 4.8% for previously ruptured lesions [74,77]. Imaging findings associated with higher hemorrhage risk include intranidal aneurysm, deep venous drainage, deep location, or venous outflow obstruction [74,78]. Treatment for AVMs include surgical resection, endovascular embolization, stereotactic radiosurgery, or medical management. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the screening of patients at high risk for cerebral aneurysm. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the screening of patients at high risk for cerebral aneurysm. Variant 6: Known high-flow vascular malformation (AVM/AVF). Surveillance monitoring. Intracranial high-flow vascular malformations include arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). Both lesions are defined by an abnormal connection between the relatively high-pressure arterial system and the low-pressure venous system resulting in a high-flow shunting of blood. AVMs are direct connections of artery to vein via abnormal dilated vascular channels without normal intermediary capillary bed. The abnormal dilated vascular channels are known as the nidus [74]. Although the true incidence of brain AVM is unknown, asymptomatic prevalence on MRI is estimated at 0.05% [74,75]. Between 10% and 20% of patients with hereditary hemorrhagic telangiectasia will have at least one AVM during their lifetime [74,76]. CVD-Aneurysm, Vascular Malformation, and SAH Symptomatic brain AVMs present most commonly with hemorrhage or epilepsy [74]. The annual rupture risk of a brain AVM is 1.3% for previously unruptured AVM and up to 4.8% for previously ruptured lesions [74,77]. Imaging findings associated with higher hemorrhage risk include intranidal aneurysm, deep venous drainage, deep location, or venous outflow obstruction [74,78]. Treatment for AVMs include surgical resection, endovascular embolization, stereotactic radiosurgery, or medical management. | 3149013 |
acrac_3149013_14 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | The ARUBA (A Randomised trial of Unruptured Brain Arteriovenous Malformations) trial concluded medical management alone was superior to medical management with interventional therapy for the prevention of death or stroke in patients with unruptured brain AVMs [79]. However, the trial did not establish the benefit of interventional treatment of unruptured AVMs, which remains a debated issue. The optimal methods for surveillance of untreated AVMs is not well established in the literature. However, treated lesions usually require long-term follow-up, specifically lesions treated with radiosurgery or embolization. Intracranial dural AVF (dAVF) is an abnormal shunt between a dural artery and venous sinus or cortical vein. dAVFs demonstrate similar high-flow vascular shunting but lack the central nidus associated with AVM. Signs and symptoms of dAVF depend on the location, with posterior dural venous sinus lesion frequently presenting with pulsatile tinnitus or cavernous sinus lesions presenting with pain, proptosis, chemosis, and ophthalmoplegia [80]. Complications of high-grade dAVF include hemorrhage or nonhemorrhagic neurologic defects and are associated with retrograde cortical venous drainage [80-83]. Treatment via endovascular or microsurgical approach is usually indicated in high-grade dAVF with cortical venous drainage or symptomatic lesions. Observation can be utilized in lower-grade lesions with less risk of hemorrhagic or neurologic complications [80,83]. This variant covers the surveillance of both treated and untreated high-flow vascular malformations. Arteriography Cervicocerebral Cervicocerebral angiography remains the reference standard for imaging of cerebrovascular disease, including AVM and dAVF. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. The ARUBA (A Randomised trial of Unruptured Brain Arteriovenous Malformations) trial concluded medical management alone was superior to medical management with interventional therapy for the prevention of death or stroke in patients with unruptured brain AVMs [79]. However, the trial did not establish the benefit of interventional treatment of unruptured AVMs, which remains a debated issue. The optimal methods for surveillance of untreated AVMs is not well established in the literature. However, treated lesions usually require long-term follow-up, specifically lesions treated with radiosurgery or embolization. Intracranial dural AVF (dAVF) is an abnormal shunt between a dural artery and venous sinus or cortical vein. dAVFs demonstrate similar high-flow vascular shunting but lack the central nidus associated with AVM. Signs and symptoms of dAVF depend on the location, with posterior dural venous sinus lesion frequently presenting with pulsatile tinnitus or cavernous sinus lesions presenting with pain, proptosis, chemosis, and ophthalmoplegia [80]. Complications of high-grade dAVF include hemorrhage or nonhemorrhagic neurologic defects and are associated with retrograde cortical venous drainage [80-83]. Treatment via endovascular or microsurgical approach is usually indicated in high-grade dAVF with cortical venous drainage or symptomatic lesions. Observation can be utilized in lower-grade lesions with less risk of hemorrhagic or neurologic complications [80,83]. This variant covers the surveillance of both treated and untreated high-flow vascular malformations. Arteriography Cervicocerebral Cervicocerebral angiography remains the reference standard for imaging of cerebrovascular disease, including AVM and dAVF. | 3149013 |
acrac_3149013_15 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Angiography demonstrates high spatial and temporal resolution of critical importance in the characterization of the intranidal aneurysm in AVM as well as potentially small arterial feeding vessels and venous drainage characteristics in both AVM and dAVF. Arteriography is critical in planning treatment in all high-flow intracranial vascular malformations. Specifically, an arteriogram of an AVM provides high-resolution imaging of the nidus; however, 2-D angiographic images may overestimate lesion volumes when compared with MRA or CTA [84]. The addition of 3-D rotational cerebral arteriography results in more precise AVM nidus volume measurement when compared with CT and MRI [85]. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the surveillance of high-flow intracranial vascular malformations. CT Head Although larger AVMs can be visualized on CT head because of hyperattenuating prominent vascular structures [83] and the osseous landmarks can be useful in radiation therapy treatment planning [85], there is no relevant literature to support the use of CT head in the surveillance of high-flow intracranial vascular malformations. CTA Head Sensitivity of CTA head was shown to be 90% for the overall detection of AVMs, 100% for AVMs >3 cm, and 88% for associated flow-related aneurysms when compared with DSA [86]. For high-flow AVFs, CTA head demonstrated a sensitivity of 86% and specificity of 100% in patients with pulsatile tinnitus [87]. Indirect signs of cortical venous drainage, indicating higher-risk lesion for future complication, on CTA exhibited sensitivities between 96% for cortical venous dilatation and 62% for identification of a medullary or pial vein. Drawbacks to CTA for surveillance monitoring include the lack of temporal resolution to directly determine flow dynamics of complex vascular lesions. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Angiography demonstrates high spatial and temporal resolution of critical importance in the characterization of the intranidal aneurysm in AVM as well as potentially small arterial feeding vessels and venous drainage characteristics in both AVM and dAVF. Arteriography is critical in planning treatment in all high-flow intracranial vascular malformations. Specifically, an arteriogram of an AVM provides high-resolution imaging of the nidus; however, 2-D angiographic images may overestimate lesion volumes when compared with MRA or CTA [84]. The addition of 3-D rotational cerebral arteriography results in more precise AVM nidus volume measurement when compared with CT and MRI [85]. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the surveillance of high-flow intracranial vascular malformations. CT Head Although larger AVMs can be visualized on CT head because of hyperattenuating prominent vascular structures [83] and the osseous landmarks can be useful in radiation therapy treatment planning [85], there is no relevant literature to support the use of CT head in the surveillance of high-flow intracranial vascular malformations. CTA Head Sensitivity of CTA head was shown to be 90% for the overall detection of AVMs, 100% for AVMs >3 cm, and 88% for associated flow-related aneurysms when compared with DSA [86]. For high-flow AVFs, CTA head demonstrated a sensitivity of 86% and specificity of 100% in patients with pulsatile tinnitus [87]. Indirect signs of cortical venous drainage, indicating higher-risk lesion for future complication, on CTA exhibited sensitivities between 96% for cortical venous dilatation and 62% for identification of a medullary or pial vein. Drawbacks to CTA for surveillance monitoring include the lack of temporal resolution to directly determine flow dynamics of complex vascular lesions. | 3149013 |
acrac_3149013_16 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | CTA Neck There is no relevant literature to support the use of CTA neck in the surveillance of high-flow intracranial vascular malformations. CTA neck may be useful for potential treatment planning, but preference will be individual or site specific. CTV Head There is no relevant literature to support the use of CTV head in the surveillance of high-flow intracranial vascular malformations. CVD-Aneurysm, Vascular Malformation, and SAH MRA Head MRA head is frequently used in surveillance of known high-flow vascular malformations. In the setting of AVM, time-of-flight and contrast-enhanced MRA offer good diagnostic accuracy but lack temporal resolution for hemodynamics and information regarding the small angioarchitecture [88]. Multiple 4-D MRA techniques are available to provide temporal resolution with trade-off in spatial resolution. Although 4-D MRA demonstrates good agreement with DSA [89-91], MRA has limited sensitivity for small nidus (<1 cm) or complete resolution after treatment [88,92]. For AVF, time-of-flight MRA demonstrates excellent intermodality agreement with DSA regarding the location of the fistula site and good agreement regarding the arterial feeding vessels and venous drainage [93]. Time-of-flight and contrast-enhanced MRA demonstrated slightly lower negative predictive values in the evaluation of signs of cortical venous reflux when compared with CTA [94]. There is good to excellent correlation of 4-D MRA techniques to DSA demonstrated in multiple studies [95-97]. MRA Neck There is no relevant literature to support the use of MRA neck in the surveillance of high-flow intracranial vascular malformations. MRA neck may be useful for potential treatment planning, but preference will be individual or site specific. MRI Head Perfusion MRI head perfusion demonstrates variable perfusion abnormalities in the evaluation of hemodynamic physiology of AVM [83]. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. CTA Neck There is no relevant literature to support the use of CTA neck in the surveillance of high-flow intracranial vascular malformations. CTA neck may be useful for potential treatment planning, but preference will be individual or site specific. CTV Head There is no relevant literature to support the use of CTV head in the surveillance of high-flow intracranial vascular malformations. CVD-Aneurysm, Vascular Malformation, and SAH MRA Head MRA head is frequently used in surveillance of known high-flow vascular malformations. In the setting of AVM, time-of-flight and contrast-enhanced MRA offer good diagnostic accuracy but lack temporal resolution for hemodynamics and information regarding the small angioarchitecture [88]. Multiple 4-D MRA techniques are available to provide temporal resolution with trade-off in spatial resolution. Although 4-D MRA demonstrates good agreement with DSA [89-91], MRA has limited sensitivity for small nidus (<1 cm) or complete resolution after treatment [88,92]. For AVF, time-of-flight MRA demonstrates excellent intermodality agreement with DSA regarding the location of the fistula site and good agreement regarding the arterial feeding vessels and venous drainage [93]. Time-of-flight and contrast-enhanced MRA demonstrated slightly lower negative predictive values in the evaluation of signs of cortical venous reflux when compared with CTA [94]. There is good to excellent correlation of 4-D MRA techniques to DSA demonstrated in multiple studies [95-97]. MRA Neck There is no relevant literature to support the use of MRA neck in the surveillance of high-flow intracranial vascular malformations. MRA neck may be useful for potential treatment planning, but preference will be individual or site specific. MRI Head Perfusion MRI head perfusion demonstrates variable perfusion abnormalities in the evaluation of hemodynamic physiology of AVM [83]. | 3149013 |
acrac_3149013_17 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Perfusion examinations, including arterial spin-labeled perfusion imaging, may have a role in the evaluation of improved perfusion from obliteration of AVMs after radiation therapy [98]. MRI Head High-flow intracranial vascular malformations can be identified on MRI head because of dilated vessels. In a study evaluating MRI and AVM, T2-weighted images demonstrated overall sensitivity of 89% and 100% for lesions >3 cm as well as low (29%) sensitivity for AVM-associated aneurysms [86]. MRI can also provide important information regarding the associated brain parenchyma including ischemia on diffusion-weighted imaging or gliosis on T2 and Fluid-attenuated inversion-recovery imaging [83]. MRV Head There is no relevant literature to support the use of MRV head in the surveillance of high-flow intracranial vascular malformations. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the surveillance of high- flow intracranial vascular malformations. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the surveillance of high-flow intracranial vascular malformations. Primary CNS vasculitis is a rare disorder with 2.4 cases per 1 million person-years [99,101]. Primary CNS vasculitis typically presents with headache, followed by encephalopathy and behavioral changes. Focal neurological deficit occurs in 20% to 30% of patients. Seizures and intracranial hemorrhage may also occur. The diagnosis of primary CNS vasculitis is challenging because of its nonspecific and varied symptoms. Diagnostic criteria for CNS vasculitis CVD-Aneurysm, Vascular Malformation, and SAH proposed by Calabrese and Mallek in 1988 required diagnosis via histopathology or characteristic findings on DSA [102,103]. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Perfusion examinations, including arterial spin-labeled perfusion imaging, may have a role in the evaluation of improved perfusion from obliteration of AVMs after radiation therapy [98]. MRI Head High-flow intracranial vascular malformations can be identified on MRI head because of dilated vessels. In a study evaluating MRI and AVM, T2-weighted images demonstrated overall sensitivity of 89% and 100% for lesions >3 cm as well as low (29%) sensitivity for AVM-associated aneurysms [86]. MRI can also provide important information regarding the associated brain parenchyma including ischemia on diffusion-weighted imaging or gliosis on T2 and Fluid-attenuated inversion-recovery imaging [83]. MRV Head There is no relevant literature to support the use of MRV head in the surveillance of high-flow intracranial vascular malformations. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the surveillance of high- flow intracranial vascular malformations. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the surveillance of high-flow intracranial vascular malformations. Primary CNS vasculitis is a rare disorder with 2.4 cases per 1 million person-years [99,101]. Primary CNS vasculitis typically presents with headache, followed by encephalopathy and behavioral changes. Focal neurological deficit occurs in 20% to 30% of patients. Seizures and intracranial hemorrhage may also occur. The diagnosis of primary CNS vasculitis is challenging because of its nonspecific and varied symptoms. Diagnostic criteria for CNS vasculitis CVD-Aneurysm, Vascular Malformation, and SAH proposed by Calabrese and Mallek in 1988 required diagnosis via histopathology or characteristic findings on DSA [102,103]. | 3149013 |
acrac_3149013_18 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Although angiographic diagnosis continues to be accepted by some authors [104], other authors have proposed diagnostic criteria that do not accept diagnosis based on angiography and require histology from biopsy or autopsy [105]. With a strong clinical suspicion, brain imaging is important for supporting the diagnostic process and directing biopsy [99,106]. Imaging examinations with CNS vasculitis demonstrate numerous nonspecific findings, such as infarcts, white matter injury, mass lesions, meningeal enhancement, or hemorrhage. Characteristic vessel imaging findings, though not always present on histologically proven cases, include multifocal stenosis and dilatation of the intracranial vasculature as well as characteristic pattern of vessel wall inflammation [107]. Many of the imaging features overlap with other cerebrovascular diseases, such as reversible cerebral vasoconstriction syndrome or atherosclerotic disease. Arteriography Cervicocerebral Cerebral arteriography has long been the standard in imaging diagnosis of CNS vasculitis due to its submillimeter resolution. However, cerebral angiography has low specificity for vasculitis given significant overlap of findings with other cerebrovascular diseases, such as atherosclerosis or reversible cerebral vasoconstriction syndrome, and limited sensitivity as the degree of vascular involvement can be below angiography resolution [99,107]. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the initial imaging for suspected CNS vasculitis. CT Head There is no relevant literature to support the use of CT head in the initial imaging for suspected CNS vasculitis. CTA Head CTA head can characterize intracranial vessel luminal characteristics with limited resolution and evaluation of the distal small arteries. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Although angiographic diagnosis continues to be accepted by some authors [104], other authors have proposed diagnostic criteria that do not accept diagnosis based on angiography and require histology from biopsy or autopsy [105]. With a strong clinical suspicion, brain imaging is important for supporting the diagnostic process and directing biopsy [99,106]. Imaging examinations with CNS vasculitis demonstrate numerous nonspecific findings, such as infarcts, white matter injury, mass lesions, meningeal enhancement, or hemorrhage. Characteristic vessel imaging findings, though not always present on histologically proven cases, include multifocal stenosis and dilatation of the intracranial vasculature as well as characteristic pattern of vessel wall inflammation [107]. Many of the imaging features overlap with other cerebrovascular diseases, such as reversible cerebral vasoconstriction syndrome or atherosclerotic disease. Arteriography Cervicocerebral Cerebral arteriography has long been the standard in imaging diagnosis of CNS vasculitis due to its submillimeter resolution. However, cerebral angiography has low specificity for vasculitis given significant overlap of findings with other cerebrovascular diseases, such as atherosclerosis or reversible cerebral vasoconstriction syndrome, and limited sensitivity as the degree of vascular involvement can be below angiography resolution [99,107]. CT Head Perfusion There is no relevant literature to support the use of CT head perfusion in the initial imaging for suspected CNS vasculitis. CT Head There is no relevant literature to support the use of CT head in the initial imaging for suspected CNS vasculitis. CTA Head CTA head can characterize intracranial vessel luminal characteristics with limited resolution and evaluation of the distal small arteries. | 3149013 |
acrac_3149013_19 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Findings of CNS vasculitis on CTA include multifocal vessel wall narrowing and dilatation with considerable overlap with other nonvasculitis cerebral vascular diseases and sensitivity is limited to resolution [99]. CTV Head There is no relevant literature to support the use of CTV head in the initial imaging for suspected CNS vasculitis. MRA Head MRA head offers a noninvasive and radiation free examination of the intracranial vessels. As stated above in the arteriography and CTA head sections, specificity of vascular luminal imaging is limited by considerable overlap with other cerebrovascular disease, such as atherosclerosis and reversible cerebral vasoconstriction syndrome, and sensitivity is limited to resolution as vasculitis can involve small distal arteries below native resolution of MRA [99]. In a recent retrospective comparison of time-of-flight MRA to DSA, time-of-flight MRA was abnormal in 81% of patients with angiographic findings of vasculitis and normal in 100% of patients with a normal angiogram. Although postcontrast imaging is utilized in vessel wall imaging MRI brain protocols and MRA is typically included in the imaging protocol, no relevant literature supports the use of postcontrast MRA in the initial imaging for suspected CNS vasculitis. MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the initial imaging for suspected CNS vasculitis. CVD-Aneurysm, Vascular Malformation, and SAH MRI Head MRI head is a useful examination in the evaluation of CNS vasculitis given its superior soft-tissue characteristics of the brain parenchyma and vessel walls. Multiple infarcts of variable ages are identified on MRI in up to 50% of patients with CNS vasculitis [99,101]. Other findings of primary CNS vasculitis include mass lesions, meningeal enhancement, and hemorrhage in 5%, 8%, and 9% of cases, respectively [99,101]. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Findings of CNS vasculitis on CTA include multifocal vessel wall narrowing and dilatation with considerable overlap with other nonvasculitis cerebral vascular diseases and sensitivity is limited to resolution [99]. CTV Head There is no relevant literature to support the use of CTV head in the initial imaging for suspected CNS vasculitis. MRA Head MRA head offers a noninvasive and radiation free examination of the intracranial vessels. As stated above in the arteriography and CTA head sections, specificity of vascular luminal imaging is limited by considerable overlap with other cerebrovascular disease, such as atherosclerosis and reversible cerebral vasoconstriction syndrome, and sensitivity is limited to resolution as vasculitis can involve small distal arteries below native resolution of MRA [99]. In a recent retrospective comparison of time-of-flight MRA to DSA, time-of-flight MRA was abnormal in 81% of patients with angiographic findings of vasculitis and normal in 100% of patients with a normal angiogram. Although postcontrast imaging is utilized in vessel wall imaging MRI brain protocols and MRA is typically included in the imaging protocol, no relevant literature supports the use of postcontrast MRA in the initial imaging for suspected CNS vasculitis. MRI Head Perfusion There is no relevant literature to support the use of MRI head perfusion in the initial imaging for suspected CNS vasculitis. CVD-Aneurysm, Vascular Malformation, and SAH MRI Head MRI head is a useful examination in the evaluation of CNS vasculitis given its superior soft-tissue characteristics of the brain parenchyma and vessel walls. Multiple infarcts of variable ages are identified on MRI in up to 50% of patients with CNS vasculitis [99,101]. Other findings of primary CNS vasculitis include mass lesions, meningeal enhancement, and hemorrhage in 5%, 8%, and 9% of cases, respectively [99,101]. | 3149013 |
acrac_3149013_20 | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs | Progressive confluent white matter lesions, cortical and subcortical T2 lesions, multiple microhemorrhages, large single or multiple enhancing mass lesions, and enhancing small vessels/perivascular spaces are also seen [105]. Although parenchymal abnormalities on MRI have considerable overlap with other CNS diseases, sensitivity of a normal MRI for CNS vasculitis approaches 100% [99,101]. Recent advances in MRI intracranial vessel wall imaging shows promise in helping to differentiate CNS vasculitis from other cerebrovascular diseases as inflammatory changes of the vessel wall differ between conditions, whereas luminal stenoses and dilations can overlap [99,107-109]. In a recent retrospective study, the addition of contrast- enhanced MRI vessel wall imaging to luminal imaging (DSA, CTA, or MRA) increased radiological diagnostic accuracy to 89% when compared with 36% in luminal imaging alone in differentiating among nonocclusive cerebrovascular diseases. In this study the reference standard was the clinical diagnosis, so it remains to be determined whether these findings have any clinical value [107]. MRV Head There is no relevant literature to support the use of MRV head in the initial imaging for suspected CNS vasculitis. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the initial imaging for suspected CNS vasculitis. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the initial imaging for suspected CNS vasculitis. CVD-Aneurysm, Vascular Malformation, and SAH Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch. acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation. | Cerebrovascular Diseases Aneurysm Vascular Malformation and Subarachnoid Hemorrhage PCAs. Progressive confluent white matter lesions, cortical and subcortical T2 lesions, multiple microhemorrhages, large single or multiple enhancing mass lesions, and enhancing small vessels/perivascular spaces are also seen [105]. Although parenchymal abnormalities on MRI have considerable overlap with other CNS diseases, sensitivity of a normal MRI for CNS vasculitis approaches 100% [99,101]. Recent advances in MRI intracranial vessel wall imaging shows promise in helping to differentiate CNS vasculitis from other cerebrovascular diseases as inflammatory changes of the vessel wall differ between conditions, whereas luminal stenoses and dilations can overlap [99,107-109]. In a recent retrospective study, the addition of contrast- enhanced MRI vessel wall imaging to luminal imaging (DSA, CTA, or MRA) increased radiological diagnostic accuracy to 89% when compared with 36% in luminal imaging alone in differentiating among nonocclusive cerebrovascular diseases. In this study the reference standard was the clinical diagnosis, so it remains to be determined whether these findings have any clinical value [107]. MRV Head There is no relevant literature to support the use of MRV head in the initial imaging for suspected CNS vasculitis. US Duplex Doppler Carotid Artery There is no relevant literature to support the use of carotid artery US duplex Doppler in the initial imaging for suspected CNS vasculitis. US Duplex Doppler Transcranial There is no relevant literature to support the use of TCD in the initial imaging for suspected CNS vasculitis. CVD-Aneurysm, Vascular Malformation, and SAH Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch. acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation. | 3149013 |
acrac_69441_0 | Seizures Child | Introduction/Background Epilepsy is defined as recurrent and unprovoked seizures and is one of the most common neurologic disorders. Status epilepticus is the most common neurologic emergency in children. The Centers for Disease Control and Prevention estimate that approximately 470,000 or 0.6% of children <17 years of age suffer from epilepsy, and approximately 50,000 new cases are being diagnosed in this age group every year [1]. OR Discussion of Procedures by Variant Variant 1: Neonatal seizures, age 0 to 29 days. Initial imaging. The incidence of neonatal seizures has been estimated to be 3 per 1,000 live births per year [5]. The incidence is higher in preterm infants (57 to 132 per 1,000 live births) [6]. In the neonatal age group, seizures from acute symptomatic causes are much more common than neonatal idiopathic epilepsies [7]. Studies demonstrate that an Reprint requests to: [email protected] MRI Head MRI is utilized to evaluate the extent and characteristics of parenchymal brain abnormalities in neonates with seizures [10]. Because hypoxic ischemic encephalopathy is the most common cause of neonatal seizures, diffusion- weighted imaging is the most sensitive sequence to detect an abnormality when performed at the appropriate time- interval [13]. In addition, MRI has the greatest sensitivity for detecting intracranial developmental abnormalities associated with seizures, including malformations of cortical development [14]. In a study of neonates with seizures, MRI showed findings in 11.9% of patients which were not apparent on cranial US, and in 39.8% of patients, MRI contributed to a diagnosis by providing information additional to cranial US [8]. Data are being accumulated establishing the prognostic value of MRI in neonates with seizures that demonstrates that the absence of major cerebral lesions on MRI is highly predictive of a normal neurological outcome [5,15]. | Seizures Child. Introduction/Background Epilepsy is defined as recurrent and unprovoked seizures and is one of the most common neurologic disorders. Status epilepticus is the most common neurologic emergency in children. The Centers for Disease Control and Prevention estimate that approximately 470,000 or 0.6% of children <17 years of age suffer from epilepsy, and approximately 50,000 new cases are being diagnosed in this age group every year [1]. OR Discussion of Procedures by Variant Variant 1: Neonatal seizures, age 0 to 29 days. Initial imaging. The incidence of neonatal seizures has been estimated to be 3 per 1,000 live births per year [5]. The incidence is higher in preterm infants (57 to 132 per 1,000 live births) [6]. In the neonatal age group, seizures from acute symptomatic causes are much more common than neonatal idiopathic epilepsies [7]. Studies demonstrate that an Reprint requests to: [email protected] MRI Head MRI is utilized to evaluate the extent and characteristics of parenchymal brain abnormalities in neonates with seizures [10]. Because hypoxic ischemic encephalopathy is the most common cause of neonatal seizures, diffusion- weighted imaging is the most sensitive sequence to detect an abnormality when performed at the appropriate time- interval [13]. In addition, MRI has the greatest sensitivity for detecting intracranial developmental abnormalities associated with seizures, including malformations of cortical development [14]. In a study of neonates with seizures, MRI showed findings in 11.9% of patients which were not apparent on cranial US, and in 39.8% of patients, MRI contributed to a diagnosis by providing information additional to cranial US [8]. Data are being accumulated establishing the prognostic value of MRI in neonates with seizures that demonstrates that the absence of major cerebral lesions on MRI is highly predictive of a normal neurological outcome [5,15]. | 69441 |
acrac_69441_1 | Seizures Child | There are potential risks associated with performing MRI in neonates who are in the intensive care unit, including the risks associated with transportation, positioning, and sedation of the patient in the setting of physiologic instability. The use of MRI- compatible incubators and small footprint MRI scanners can help with safer transportation and imaging of the patient. CT Head CT has a limited but specific role in the evaluation of neonates with seizures. A noncontrast CT can be performed to detect hemorrhagic lesions in the encephalopathic infant with a history of birth trauma, low hematocrit, or coagulopathy. CT may help to define the extent of intracranial hemorrhage and is useful in quantifying and characterizing extra-axial collections, but CT is less sensitive than MRI for detecting hypoxic ischemic events and structural anomalies [7]. CT is helpful in identifying calcifications in a suspected intrauterine infection, any associated traumatic abnormalities, and in the identification of dural sinus thrombosis. CT is rapid, does not require sedation, and may provide better assessment of the brain compared with US in scenarios in which acute hemorrhage, stroke, or hydrocephalus is suspected. FDG-PET/CT Brain There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT in the workup of a neonate with seizures. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m hexamethylpropyleneamine oxime (HMPAO) single- photon emission computed tomography (SPECT) or SPECT/CT in the workup of a neonate with seizures. Seizures-Child US Head There is no relevant literature to support the use of US in the workup of a child with simple febrile seizures. MRI Head MRI is not indicated in the workup of a child with simple febrile seizures. | Seizures Child. There are potential risks associated with performing MRI in neonates who are in the intensive care unit, including the risks associated with transportation, positioning, and sedation of the patient in the setting of physiologic instability. The use of MRI- compatible incubators and small footprint MRI scanners can help with safer transportation and imaging of the patient. CT Head CT has a limited but specific role in the evaluation of neonates with seizures. A noncontrast CT can be performed to detect hemorrhagic lesions in the encephalopathic infant with a history of birth trauma, low hematocrit, or coagulopathy. CT may help to define the extent of intracranial hemorrhage and is useful in quantifying and characterizing extra-axial collections, but CT is less sensitive than MRI for detecting hypoxic ischemic events and structural anomalies [7]. CT is helpful in identifying calcifications in a suspected intrauterine infection, any associated traumatic abnormalities, and in the identification of dural sinus thrombosis. CT is rapid, does not require sedation, and may provide better assessment of the brain compared with US in scenarios in which acute hemorrhage, stroke, or hydrocephalus is suspected. FDG-PET/CT Brain There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT in the workup of a neonate with seizures. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m hexamethylpropyleneamine oxime (HMPAO) single- photon emission computed tomography (SPECT) or SPECT/CT in the workup of a neonate with seizures. Seizures-Child US Head There is no relevant literature to support the use of US in the workup of a child with simple febrile seizures. MRI Head MRI is not indicated in the workup of a child with simple febrile seizures. | 69441 |
acrac_69441_2 | Seizures Child | In a small prospective study of children with febrile seizures, definite abnormalities on brain MRI were found in 11.4% of children with simple febrile seizures, suggesting that brain abnormalities may lower seizure threshold in febrile children, but none of the imaging findings affected clinical management, hence it did not alter the recommendation that imaging is not indicated [17,18]. CT Head There is no relevant literature to support the use of CT in the workup of a child with simple febrile seizures. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the workup of a child with simple febrile seizures. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m HMPAO SPECT or SPECT/CT in the workup of a child with simple febrile seizures. Variant 3: Children 6 months to 5 years of age. Complex febrile seizures. Initial imaging. Complex febrile seizures account for about a third of all febrile seizures in infants and young children (6 months to 5 years of age). Complex febrile seizures are defined as seizures that last >15 minutes, recur more than once in 24 hours, or are focal [19,20]. Seizures in the setting of fever associated with underlying pathology, such as meningitis, encephalitis, or child abuse may present similarly, but are not considered complex febrile seizures by definition. There is a small increased risk for children with complex febrile seizures to develop epilepsy (ie, subsequent afebrile seizures) later in life, but other than an EEG and evaluation by a neurologist, imaging recommendations are the same as for simple febrile seizures [21]. US Head There is no relevant literature to support the use of US in the workup of a child with complex febrile seizures. MRI Head In one study of children with febrile seizures recurrent within 24 hours, neuroimaging revealed benign findings in 7.4% of patients and did not add significant diagnostic or prognostic information [17]. | Seizures Child. In a small prospective study of children with febrile seizures, definite abnormalities on brain MRI were found in 11.4% of children with simple febrile seizures, suggesting that brain abnormalities may lower seizure threshold in febrile children, but none of the imaging findings affected clinical management, hence it did not alter the recommendation that imaging is not indicated [17,18]. CT Head There is no relevant literature to support the use of CT in the workup of a child with simple febrile seizures. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the workup of a child with simple febrile seizures. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m HMPAO SPECT or SPECT/CT in the workup of a child with simple febrile seizures. Variant 3: Children 6 months to 5 years of age. Complex febrile seizures. Initial imaging. Complex febrile seizures account for about a third of all febrile seizures in infants and young children (6 months to 5 years of age). Complex febrile seizures are defined as seizures that last >15 minutes, recur more than once in 24 hours, or are focal [19,20]. Seizures in the setting of fever associated with underlying pathology, such as meningitis, encephalitis, or child abuse may present similarly, but are not considered complex febrile seizures by definition. There is a small increased risk for children with complex febrile seizures to develop epilepsy (ie, subsequent afebrile seizures) later in life, but other than an EEG and evaluation by a neurologist, imaging recommendations are the same as for simple febrile seizures [21]. US Head There is no relevant literature to support the use of US in the workup of a child with complex febrile seizures. MRI Head In one study of children with febrile seizures recurrent within 24 hours, neuroimaging revealed benign findings in 7.4% of patients and did not add significant diagnostic or prognostic information [17]. | 69441 |
acrac_69441_3 | Seizures Child | Compared with children with simple febrile seizures, children with complex febrile seizures were found to be more likely to have an imaging abnormality (14.8% in patients with complex febrile seizures and 11.4% in patients with simple febrile seizures), but these findings did not alter the clinical management. In the absence of other neurological indications such as post ictal focal deficits, neuroimaging in complex febrile seizures is unnecessary [18]. Imaging may be performed in selected patients where complex febrile seizure is part of the differential diagnosis but etiologies such as meningitis, encephalitis, or trauma are being considered clinically as the underlying cause of the seizures [19,22]. MRI may also be indicated in children with febrile status epilepticus (seizure lasting >30 minutes) because increased association with imaging findings have been demonstrated in this patient population [23]. CT Head CT is usually not indicated in the workup of a child with complex febrile seizures. An analysis of six studies, including a total of 161 children with complex febrile seizures, demonstrated that head CT revealed no findings requiring intervention [22]. FDG-PET/CT Brain FDG-PET/CT is usually not indicated in the workup of a child with complex febrile seizures. HMPAO SPECT or SPECT/CT Brain Tc-99m HMPAO SPECT or SPECT/CT is usually not indicated in the workup of a child with complex febrile seizures. Seizures-Child US Head There is no relevant literature to support the use of US in the workup of a child with post-traumatic seizures. MRI Head A typical MRI examination is longer compared with CT and may not be suited for an intimal examination in the acute trauma setting. MRI may not be practically feasible compared with CT, depending on the overall clinical status of the child. However, MRI has high sensitivity for detecting intracranial hemorrhage, microhemorrhage, and parenchymal injury. | Seizures Child. Compared with children with simple febrile seizures, children with complex febrile seizures were found to be more likely to have an imaging abnormality (14.8% in patients with complex febrile seizures and 11.4% in patients with simple febrile seizures), but these findings did not alter the clinical management. In the absence of other neurological indications such as post ictal focal deficits, neuroimaging in complex febrile seizures is unnecessary [18]. Imaging may be performed in selected patients where complex febrile seizure is part of the differential diagnosis but etiologies such as meningitis, encephalitis, or trauma are being considered clinically as the underlying cause of the seizures [19,22]. MRI may also be indicated in children with febrile status epilepticus (seizure lasting >30 minutes) because increased association with imaging findings have been demonstrated in this patient population [23]. CT Head CT is usually not indicated in the workup of a child with complex febrile seizures. An analysis of six studies, including a total of 161 children with complex febrile seizures, demonstrated that head CT revealed no findings requiring intervention [22]. FDG-PET/CT Brain FDG-PET/CT is usually not indicated in the workup of a child with complex febrile seizures. HMPAO SPECT or SPECT/CT Brain Tc-99m HMPAO SPECT or SPECT/CT is usually not indicated in the workup of a child with complex febrile seizures. Seizures-Child US Head There is no relevant literature to support the use of US in the workup of a child with post-traumatic seizures. MRI Head A typical MRI examination is longer compared with CT and may not be suited for an intimal examination in the acute trauma setting. MRI may not be practically feasible compared with CT, depending on the overall clinical status of the child. However, MRI has high sensitivity for detecting intracranial hemorrhage, microhemorrhage, and parenchymal injury. | 69441 |
acrac_69441_4 | Seizures Child | Sequences such as susceptibility-weighted imaging and diffusion-weighted imaging are helpful in identifying patients with diffuse axonal injury [27], that is typically not apparent on CT examinations. At an interval after trauma, MRI can be useful in the evaluation of post-traumatic epilepsy, allowing for better identification and delineation of the sequela of prior traumatic brain injury, including gliosis, and volume loss. CT Head If imaging is pursued, CT may be useful in the acute post-traumatic settings especially to identify acute intracranial hemorrhage or mass effect. In a study by Lee and Lui [25], CT identified 100% of the acutely treatable lesions in patients with mild trauma. In this study, although CT results were negative in 53% of patients, 7% of patients had lesions that required urgent surgical intervention. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the acute workup of a child with post-traumatic seizures. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m HMPAO SPECT or SPECT/CT in the acute workup of a child with post-traumatic seizures. Variant 5: Children 1 month to 17 years of age. Focal seizures, not including abusive head trauma. Initial imaging. Focal seizures are defined as those with onset, limited to one hemisphere of the brain, and include focal aware seizures (retained awareness) and focal impaired awareness seizures (formerly known as complex partial seizures) [3]. Positive yields from neuroimaging of patients with focal seizures are considerably higher when compared with those from imaging of patients with generalized seizures whose neurologic examination is normal [30,31]. Presence of any focal feature to the seizure was found to be independently associated with clinically relevant abnormalities on neuroimaging [32]. Young et al [33] noted a 50% positivity rate for CT when neurologic findings were focal as compared with 6% positive CT findings in patients without focal features. | Seizures Child. Sequences such as susceptibility-weighted imaging and diffusion-weighted imaging are helpful in identifying patients with diffuse axonal injury [27], that is typically not apparent on CT examinations. At an interval after trauma, MRI can be useful in the evaluation of post-traumatic epilepsy, allowing for better identification and delineation of the sequela of prior traumatic brain injury, including gliosis, and volume loss. CT Head If imaging is pursued, CT may be useful in the acute post-traumatic settings especially to identify acute intracranial hemorrhage or mass effect. In a study by Lee and Lui [25], CT identified 100% of the acutely treatable lesions in patients with mild trauma. In this study, although CT results were negative in 53% of patients, 7% of patients had lesions that required urgent surgical intervention. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the acute workup of a child with post-traumatic seizures. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m HMPAO SPECT or SPECT/CT in the acute workup of a child with post-traumatic seizures. Variant 5: Children 1 month to 17 years of age. Focal seizures, not including abusive head trauma. Initial imaging. Focal seizures are defined as those with onset, limited to one hemisphere of the brain, and include focal aware seizures (retained awareness) and focal impaired awareness seizures (formerly known as complex partial seizures) [3]. Positive yields from neuroimaging of patients with focal seizures are considerably higher when compared with those from imaging of patients with generalized seizures whose neurologic examination is normal [30,31]. Presence of any focal feature to the seizure was found to be independently associated with clinically relevant abnormalities on neuroimaging [32]. Young et al [33] noted a 50% positivity rate for CT when neurologic findings were focal as compared with 6% positive CT findings in patients without focal features. | 69441 |
acrac_69441_5 | Seizures Child | The frequency of recurrence of focal seizures was found to be up to 94%, which is considerably greater than that for generalized seizures (72%) [34]. Several seizure syndromes (eg, benign rolandic seizures, benign occipital epilepsy with classic EEG findings) are sufficiently characteristic to be diagnosed clinically or through specific EEG patterns and usually do not require imaging. Patients that may benefit from imaging include those who do not have typical clinical or EEG findings. US Head There is no relevant literature to support the use of US in the workup of a child with focal seizures. MRI Head Seizures can result from multiple intracranial pathologies including developmental abnormalities, hemorrhage, neoplasm, and gliosis. Aprahamian et al [35] found that approximately 4% of children with first-time afebrile seizures and focal manifestations had urgent intracranial pathology, most commonly infarction, hemorrhage, and thrombosis. MRI is more sensitive than CT in detection of brain abnormalities and therefore should be the primary Seizures-Child imaging in children with newly diagnosed seizures [36]. In a study by Jan et al [37], MRI demonstrated focal brain abnormalities in 55% of children with seizures, whereas CT was positive in only 18% of children. In the Aprahamian et al [35] study, 205 of 252 children who had a CT scan for their urgent imaging also had a subsequent MRI. Of these 205 children, 58 (28.2%) had abnormal findings on MRI, 29% of abnormal intracranial findings were not seen on initial CT in children with new-onset afebrile seizures with focal features [35]. In a study by Singh et al [38], MRI detected abnormalities not identified by CT in 47% of children who presented with new-onset status epilepticus. Additionally, MRI is superior to CT in identifying peri-ictal cortical abnormalities that might explain clinical deficits after acute seizure [39]. The epileptogenic lesion may not be detected using routine MRI protocols. | Seizures Child. The frequency of recurrence of focal seizures was found to be up to 94%, which is considerably greater than that for generalized seizures (72%) [34]. Several seizure syndromes (eg, benign rolandic seizures, benign occipital epilepsy with classic EEG findings) are sufficiently characteristic to be diagnosed clinically or through specific EEG patterns and usually do not require imaging. Patients that may benefit from imaging include those who do not have typical clinical or EEG findings. US Head There is no relevant literature to support the use of US in the workup of a child with focal seizures. MRI Head Seizures can result from multiple intracranial pathologies including developmental abnormalities, hemorrhage, neoplasm, and gliosis. Aprahamian et al [35] found that approximately 4% of children with first-time afebrile seizures and focal manifestations had urgent intracranial pathology, most commonly infarction, hemorrhage, and thrombosis. MRI is more sensitive than CT in detection of brain abnormalities and therefore should be the primary Seizures-Child imaging in children with newly diagnosed seizures [36]. In a study by Jan et al [37], MRI demonstrated focal brain abnormalities in 55% of children with seizures, whereas CT was positive in only 18% of children. In the Aprahamian et al [35] study, 205 of 252 children who had a CT scan for their urgent imaging also had a subsequent MRI. Of these 205 children, 58 (28.2%) had abnormal findings on MRI, 29% of abnormal intracranial findings were not seen on initial CT in children with new-onset afebrile seizures with focal features [35]. In a study by Singh et al [38], MRI detected abnormalities not identified by CT in 47% of children who presented with new-onset status epilepticus. Additionally, MRI is superior to CT in identifying peri-ictal cortical abnormalities that might explain clinical deficits after acute seizure [39]. The epileptogenic lesion may not be detected using routine MRI protocols. | 69441 |
acrac_69441_6 | Seizures Child | Therefore, in these cases, an optimized epilepsy protocol with adequate spatial resolution and multiplanar reformatting is essential. A proper MRI investigation of patients with focal epilepsy requires the use of specific protocols, which are selected based on identification of the region of onset by clinical and EEG findings. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in initial management of focal seizures. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of ictal/interictal Tc-99m HMPAO SPECT or SPECT/CT in initial management of focal seizures. Variant 6: Children 1 month to 17 years of age. Primary generalized seizure (neurologically normal). Initial imaging. The term generalized seizure, implies diffuse or generalized involvement of the brain on EEG or clinically [3]. Generalized seizures differ from a focal seizure with secondary generalization (now known as focal to bilateral tonic-clonic), which starts focally and then propagates to both hemispheres [3]. According to the most recent International League Against Epilepsy seizures classification, generalized seizures are categorized as motor and nonmotor (absence) seizures, but for the purpose of a diagnostic imaging workup, it is appropriate to classify them into generalized seizures in an otherwise neurologically normal child and generalized seizures in a neurologically abnormal child [3]. US Head There is no relevant literature to support the use of US in the workup of a neurologically normal child with generalized seizure. MRI Head MRI is rarely indicated in evaluation of a neurologically normal child presenting with generalized seizures because the rate of positive intracranial findings in this group is low, given their genetic underpinnings. | Seizures Child. Therefore, in these cases, an optimized epilepsy protocol with adequate spatial resolution and multiplanar reformatting is essential. A proper MRI investigation of patients with focal epilepsy requires the use of specific protocols, which are selected based on identification of the region of onset by clinical and EEG findings. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in initial management of focal seizures. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of ictal/interictal Tc-99m HMPAO SPECT or SPECT/CT in initial management of focal seizures. Variant 6: Children 1 month to 17 years of age. Primary generalized seizure (neurologically normal). Initial imaging. The term generalized seizure, implies diffuse or generalized involvement of the brain on EEG or clinically [3]. Generalized seizures differ from a focal seizure with secondary generalization (now known as focal to bilateral tonic-clonic), which starts focally and then propagates to both hemispheres [3]. According to the most recent International League Against Epilepsy seizures classification, generalized seizures are categorized as motor and nonmotor (absence) seizures, but for the purpose of a diagnostic imaging workup, it is appropriate to classify them into generalized seizures in an otherwise neurologically normal child and generalized seizures in a neurologically abnormal child [3]. US Head There is no relevant literature to support the use of US in the workup of a neurologically normal child with generalized seizure. MRI Head MRI is rarely indicated in evaluation of a neurologically normal child presenting with generalized seizures because the rate of positive intracranial findings in this group is low, given their genetic underpinnings. | 69441 |
acrac_69441_7 | Seizures Child | MRI is typically not indicated in patients with very typical forms of primary generalized epilepsy (eg, juvenile myoclonic epilepsy, childhood absence) or patients with characteristic clinical and EEG features and patients with adequate response to antiepileptic drugs. Sharma et al [31] studied 500 consecutive emergency department patients presenting with a first afebrile seizure. They defined two clinically significant high-risk indicators of abnormal neuroimaging: 1) presence of predisposing condition, and 2) focal seizure. Only 2% of low-risk patients had abnormal imaging findings on MRI. CT Head CT is usually not indicated in the evaluation of an otherwise neurologically normal child with a generalized seizure. The frequency of positive CT findings in patients with idiopathic generalized seizures in children with normal neurologic examination and negative EEG has been estimated to be 2.5% [41,42]. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the workup of a neurologically normal child with generalized seizure. Seizures-Child HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m HMPAO SPECT/CT in the workup of a neurologically normal child with generalized seizure. US Head There is no relevant literature to support the use of US in the workup of a child with generalized seizure and abnormal neurological findings. MRI Head Patients with generalized seizures and abnormal neurologic findings can significantly benefit from MRI. MRI offers higher soft-tissue contrast than CT and provides additional information regarding brain anatomy. CT Head CT has a limited role in the evaluation of a child with generalized seizures and abnormal neurological examination. Young et al [33] reported only 6% of CT examinations were positive for generalized seizures in contrast to nearly 50% positivity in focal epilepsy. | Seizures Child. MRI is typically not indicated in patients with very typical forms of primary generalized epilepsy (eg, juvenile myoclonic epilepsy, childhood absence) or patients with characteristic clinical and EEG features and patients with adequate response to antiepileptic drugs. Sharma et al [31] studied 500 consecutive emergency department patients presenting with a first afebrile seizure. They defined two clinically significant high-risk indicators of abnormal neuroimaging: 1) presence of predisposing condition, and 2) focal seizure. Only 2% of low-risk patients had abnormal imaging findings on MRI. CT Head CT is usually not indicated in the evaluation of an otherwise neurologically normal child with a generalized seizure. The frequency of positive CT findings in patients with idiopathic generalized seizures in children with normal neurologic examination and negative EEG has been estimated to be 2.5% [41,42]. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the workup of a neurologically normal child with generalized seizure. Seizures-Child HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m HMPAO SPECT/CT in the workup of a neurologically normal child with generalized seizure. US Head There is no relevant literature to support the use of US in the workup of a child with generalized seizure and abnormal neurological findings. MRI Head Patients with generalized seizures and abnormal neurologic findings can significantly benefit from MRI. MRI offers higher soft-tissue contrast than CT and provides additional information regarding brain anatomy. CT Head CT has a limited role in the evaluation of a child with generalized seizures and abnormal neurological examination. Young et al [33] reported only 6% of CT examinations were positive for generalized seizures in contrast to nearly 50% positivity in focal epilepsy. | 69441 |
acrac_69441_8 | Seizures Child | CT may have an advantage over MRI in only uncommon situations of children with unstable clinical status with generalized seizures and abnormal neurological examination. In these cases, CT may provide initial diagnostic information that helps to guide early therapeutic decisions [44]. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the workup of a child with generalized seizure and abnormal neurological findings. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m HMPAO SPECT or SPECT/CT in the workup of a child with generalized seizure and abnormal neurological findings. Variant 8: Children 1 month to 17 years of age. Intractable seizures or refractory epilepsy. Refractory seizures define a small percentage of patients with seizures or epilepsy. In these patients, the use of both anatomical and functional imaging modalities is needed in selected cases, and some of these cases are potentially treatable by surgical intervention. Anatomic imaging with MRI may assist in determining the underlying pathology and help assess anatomical changes associated with seizure activity. Functional imaging, using MRI, PET, or SPECT, may depict seizure foci that are occult by anatomic imaging and may help guide a safe and effective surgical outcome. US Head US is not useful in the workup of a child with intractable seizures or refractory epilepsy. MRI Head MRI is considered the most sensitive and specific anatomic imaging technique in the evaluation of patients with intractable seizures and should be performed using dedicated epilepsy protocols with 3T scanners whenever possible. This includes, but is not limited to, a T1-weighted volumetric acquisition (3-D) with isotropic voxel size of 1 mm as well as images optimized for the evaluation of hippocampal pathology that include high-resolution thin coronal slices. | Seizures Child. CT may have an advantage over MRI in only uncommon situations of children with unstable clinical status with generalized seizures and abnormal neurological examination. In these cases, CT may provide initial diagnostic information that helps to guide early therapeutic decisions [44]. FDG-PET/CT Brain There is no relevant literature to support the use of FDG-PET/CT in the workup of a child with generalized seizure and abnormal neurological findings. HMPAO SPECT or SPECT/CT Brain There is no relevant literature to support the use of Tc-99m HMPAO SPECT or SPECT/CT in the workup of a child with generalized seizure and abnormal neurological findings. Variant 8: Children 1 month to 17 years of age. Intractable seizures or refractory epilepsy. Refractory seizures define a small percentage of patients with seizures or epilepsy. In these patients, the use of both anatomical and functional imaging modalities is needed in selected cases, and some of these cases are potentially treatable by surgical intervention. Anatomic imaging with MRI may assist in determining the underlying pathology and help assess anatomical changes associated with seizure activity. Functional imaging, using MRI, PET, or SPECT, may depict seizure foci that are occult by anatomic imaging and may help guide a safe and effective surgical outcome. US Head US is not useful in the workup of a child with intractable seizures or refractory epilepsy. MRI Head MRI is considered the most sensitive and specific anatomic imaging technique in the evaluation of patients with intractable seizures and should be performed using dedicated epilepsy protocols with 3T scanners whenever possible. This includes, but is not limited to, a T1-weighted volumetric acquisition (3-D) with isotropic voxel size of 1 mm as well as images optimized for the evaluation of hippocampal pathology that include high-resolution thin coronal slices. | 69441 |
acrac_69441_9 | Seizures Child | Studies have shown that in this clinical scenario, MRI has a sensitivity of 84% with specificity of 70%, whereas the sensitivity of CT is approximately 62% [45]. MRI is particularly useful in the evaluation of mesial temporal sclerosis and cortical abnormalities that may be the cause of refractory seizures [46,47]. The data are limited on the additional value of specialized MRI sequences, such as diffusion tensor imaging, which may help to improve specificity in localization of the epileptogenic lesion in cases where conventional structural MRI is Seizures-Child CT Head CT has lower sensitivity compared with MRI in localization and characterization of a potential epileptogenic focus. Available data indicate that the diagnostic yield of CT in evaluation of a child presenting with a breakthrough seizure in the setting of known refractory epilepsy is also very low. Allen et al [50] showed that in a cohort of 124 children presenting with breakthrough seizures, almost 17% underwent CT scans and none of them demonstrated acute findings. FDG-PET/CT Brain Functional imaging is most utilized for refined evaluation when surgical intervention is contemplated or when structural imaging with MRI is normal or shows nonspecific findings [36]. A study by Leach et al [51] showed that MRI failed to demonstrate findings that would allow guidance for surgery in up to 58% of patients with surgically proven focal cortical dysplasia, supporting the need for a multimodality approach and underscoring the importance of functional studies in preoperative surgical planning. FDG-PET/CT has been shown to improve lesion detection and can be a helpful modality when anatomic imaging (CT and MRI) is normal or in cases when multiple structural abnormalities are present. In a study by Kim et al [52], interictal FDG-PET was shown to have statistically significantly better detection power (P = . 013) than MRI, with the higher percentage of cases with MRI discordance and PET localization than in reverse. | Seizures Child. Studies have shown that in this clinical scenario, MRI has a sensitivity of 84% with specificity of 70%, whereas the sensitivity of CT is approximately 62% [45]. MRI is particularly useful in the evaluation of mesial temporal sclerosis and cortical abnormalities that may be the cause of refractory seizures [46,47]. The data are limited on the additional value of specialized MRI sequences, such as diffusion tensor imaging, which may help to improve specificity in localization of the epileptogenic lesion in cases where conventional structural MRI is Seizures-Child CT Head CT has lower sensitivity compared with MRI in localization and characterization of a potential epileptogenic focus. Available data indicate that the diagnostic yield of CT in evaluation of a child presenting with a breakthrough seizure in the setting of known refractory epilepsy is also very low. Allen et al [50] showed that in a cohort of 124 children presenting with breakthrough seizures, almost 17% underwent CT scans and none of them demonstrated acute findings. FDG-PET/CT Brain Functional imaging is most utilized for refined evaluation when surgical intervention is contemplated or when structural imaging with MRI is normal or shows nonspecific findings [36]. A study by Leach et al [51] showed that MRI failed to demonstrate findings that would allow guidance for surgery in up to 58% of patients with surgically proven focal cortical dysplasia, supporting the need for a multimodality approach and underscoring the importance of functional studies in preoperative surgical planning. FDG-PET/CT has been shown to improve lesion detection and can be a helpful modality when anatomic imaging (CT and MRI) is normal or in cases when multiple structural abnormalities are present. In a study by Kim et al [52], interictal FDG-PET was shown to have statistically significantly better detection power (P = . 013) than MRI, with the higher percentage of cases with MRI discordance and PET localization than in reverse. | 69441 |
acrac_69459_0 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Introduction/Background Accurate pretreatment evaluation of endometrial carcinoma (EC) may optimize therapy, particularly with regard to choosing the type of surgery. Preoperative imaging of EC can define the extent of disease and indicate the need for subspecialist referral in the presence of deep myometrial invasion, cervical extension, suspected lymphadenopathy or if high-grade endometrioid carcinoma or high-risk histology (such as papillary serous or clear cell carcinoma) is found at the time of biopsy. Cross-sectional imaging techniques play a vital role in the pretreatment assessment of uterine cancers and should be viewed as complementary modalities for surgical evaluation of these patients. The depth of myometrial invasion, cervical stromal invasion, local regional invasion of pelvic structures, and distant metastasis can be readily detected at cross-sectional imaging. Although ultrasound (US) remains the imaging modality of choice to screen women who have suspected EC, state-of-the-art dynamic contrast-enhanced and diffusion-weighted imaging (DWI) MR techniques are better suited to preoperatively stage, identify recurrence, and assess local treatment response in women with EC. Initial Staging EC is the most common gynecologic malignancy in the United States, with approximately 61,880 newly diagnosed cases and 12,160 deaths expected in 2019 [1]. Histopathologically, ECs are classified as type I (>80%) and type II (<20%) [2]. Type I tumors are typically endometrioid in histology and estrogen-dependent. They are often low- grade (grade 1 and 2) preceded by a premalignant endometrial hyperplasia and are associated with a better prognosis. Type II tumors tend to be nonestrogen dependent, nonendometrioid, high-grade endometrioid tumors (grade 3), and characteristically arise from an atrophic endometrium. They demonstrate a worse prognosis and are responsible for almost half of the EC-related deaths [3]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Introduction/Background Accurate pretreatment evaluation of endometrial carcinoma (EC) may optimize therapy, particularly with regard to choosing the type of surgery. Preoperative imaging of EC can define the extent of disease and indicate the need for subspecialist referral in the presence of deep myometrial invasion, cervical extension, suspected lymphadenopathy or if high-grade endometrioid carcinoma or high-risk histology (such as papillary serous or clear cell carcinoma) is found at the time of biopsy. Cross-sectional imaging techniques play a vital role in the pretreatment assessment of uterine cancers and should be viewed as complementary modalities for surgical evaluation of these patients. The depth of myometrial invasion, cervical stromal invasion, local regional invasion of pelvic structures, and distant metastasis can be readily detected at cross-sectional imaging. Although ultrasound (US) remains the imaging modality of choice to screen women who have suspected EC, state-of-the-art dynamic contrast-enhanced and diffusion-weighted imaging (DWI) MR techniques are better suited to preoperatively stage, identify recurrence, and assess local treatment response in women with EC. Initial Staging EC is the most common gynecologic malignancy in the United States, with approximately 61,880 newly diagnosed cases and 12,160 deaths expected in 2019 [1]. Histopathologically, ECs are classified as type I (>80%) and type II (<20%) [2]. Type I tumors are typically endometrioid in histology and estrogen-dependent. They are often low- grade (grade 1 and 2) preceded by a premalignant endometrial hyperplasia and are associated with a better prognosis. Type II tumors tend to be nonestrogen dependent, nonendometrioid, high-grade endometrioid tumors (grade 3), and characteristically arise from an atrophic endometrium. They demonstrate a worse prognosis and are responsible for almost half of the EC-related deaths [3]. | 69459 |
acrac_69459_1 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Patients with EC typically present with stage I disease (80% of cases), and the recommended treatment is complete resection of disease by hysterectomy and bilateral salpingo-oophorectomy. Multiple studies have demonstrated that recurrence risk after treatment is related to the depth of myometrial invasion, tumor grade, histological subtype, and Reprint requests to: [email protected] Evaluation and Follow-Up of Endometrial Cancer lymphovascular space invasion in clinically proven stage I [7]. Risk stratification systems that aggregate these prognostic factors to define recurrence risk groups have been developed and are now used worldwide to guide decision-making and design clinical trials [2,8-10]. Results of a 2014 study of a simultaneous comparison of several proposed risk stratification systems suggested that the European Society for Medical Oncology modified system was the most accurate in the prediction of lymph node status and survival [10]. In that system, categorization of risk grouping was based on FIGO stage, tumor grade, histological subtype, and lymphovascular space invasion. Patients with disease of FIGO stage IB grade 3 endometrioid type with positive lymphovascular space invasion or nonendometrioid histology of all stages can be classified as high risk. Conversely, patients with FIGO stage IA with grade 1 to 2 EC and no lymphovascular space invasion can be classified as low risk. All other tumors can be classified as intermediate or high-intermediate risk. This risk stratification system also guides the need and extent of lymph node sampling for initial staging [9]. Surveillance and Posttherapy Evaluation EC tends to recur in the pelvis, especially in the vaginal vault (42% of recurrences) and pelvic lymph nodes, followed by para-aortic lymph nodes [16]. Extrapelvic recurrence commonly involves the peritoneum and lungs. Atypical metastatic sites include extra-abdominal lymph nodes, liver, adrenals, brain, bones, and soft-tissue [17]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Patients with EC typically present with stage I disease (80% of cases), and the recommended treatment is complete resection of disease by hysterectomy and bilateral salpingo-oophorectomy. Multiple studies have demonstrated that recurrence risk after treatment is related to the depth of myometrial invasion, tumor grade, histological subtype, and Reprint requests to: [email protected] Evaluation and Follow-Up of Endometrial Cancer lymphovascular space invasion in clinically proven stage I [7]. Risk stratification systems that aggregate these prognostic factors to define recurrence risk groups have been developed and are now used worldwide to guide decision-making and design clinical trials [2,8-10]. Results of a 2014 study of a simultaneous comparison of several proposed risk stratification systems suggested that the European Society for Medical Oncology modified system was the most accurate in the prediction of lymph node status and survival [10]. In that system, categorization of risk grouping was based on FIGO stage, tumor grade, histological subtype, and lymphovascular space invasion. Patients with disease of FIGO stage IB grade 3 endometrioid type with positive lymphovascular space invasion or nonendometrioid histology of all stages can be classified as high risk. Conversely, patients with FIGO stage IA with grade 1 to 2 EC and no lymphovascular space invasion can be classified as low risk. All other tumors can be classified as intermediate or high-intermediate risk. This risk stratification system also guides the need and extent of lymph node sampling for initial staging [9]. Surveillance and Posttherapy Evaluation EC tends to recur in the pelvis, especially in the vaginal vault (42% of recurrences) and pelvic lymph nodes, followed by para-aortic lymph nodes [16]. Extrapelvic recurrence commonly involves the peritoneum and lungs. Atypical metastatic sites include extra-abdominal lymph nodes, liver, adrenals, brain, bones, and soft-tissue [17]. | 69459 |
acrac_69459_2 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Therefore, posttherapy surveillance imaging may include evaluation of the abdomen and pelvis. Imaging of the chest may be indicated in selected high-risk, advanced stage patients to detect lung metastasis. Close follow-up after the completion of treatment for EC is suggested, particularly in the first 3 years after diagnosis, when the risk of recurrence is highest [18]. This usually includes a history and physical examination every 3 to 6 months for several years. Vaginal bleeding is a common symptom of local recurrence. In patients with a distant recurrence, symptoms such as coughing, pain, lethargy, weight loss, or headaches are present in up to 70% of cases [19,20]. In one study, a combination of findings at physical examination with or without patient symptomatology, resulted in a >80% recurrence detection rate [21]. Radiologic evaluation such as a CT scan or fluorine-18-2-fluoro- 2-deoxy-D-glucose (FDG)-PET/CT scan of the chest, abdomen, and pelvis should only be used to investigate suspicion of recurrent disease and not for routine surveillance after treatment [22]. Whenever feasible, pathologic diagnosis with biopsy should be done to confirm disease recurrence [23]. Special Imaging Considerations MR perfusion and blood oxygen level dependent MRI do not have established roles in the evaluation of EC [24]. Evaluation and Follow-Up of Endometrial Cancer Certain ECs have demonstrated increased spectroscopic signals from choline, lipids, and lactates [24]. This reaction could be exploited to determine long-term prognosis and treatment response on MR spectroscopy but still needs validation. Magnetic iron oxide nanoparticles or ultra-small particles of iron oxides may demonstrate a potential in detecting malignant pelvic lymph nodes, but these particles are not widely available [25]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Therefore, posttherapy surveillance imaging may include evaluation of the abdomen and pelvis. Imaging of the chest may be indicated in selected high-risk, advanced stage patients to detect lung metastasis. Close follow-up after the completion of treatment for EC is suggested, particularly in the first 3 years after diagnosis, when the risk of recurrence is highest [18]. This usually includes a history and physical examination every 3 to 6 months for several years. Vaginal bleeding is a common symptom of local recurrence. In patients with a distant recurrence, symptoms such as coughing, pain, lethargy, weight loss, or headaches are present in up to 70% of cases [19,20]. In one study, a combination of findings at physical examination with or without patient symptomatology, resulted in a >80% recurrence detection rate [21]. Radiologic evaluation such as a CT scan or fluorine-18-2-fluoro- 2-deoxy-D-glucose (FDG)-PET/CT scan of the chest, abdomen, and pelvis should only be used to investigate suspicion of recurrent disease and not for routine surveillance after treatment [22]. Whenever feasible, pathologic diagnosis with biopsy should be done to confirm disease recurrence [23]. Special Imaging Considerations MR perfusion and blood oxygen level dependent MRI do not have established roles in the evaluation of EC [24]. Evaluation and Follow-Up of Endometrial Cancer Certain ECs have demonstrated increased spectroscopic signals from choline, lipids, and lactates [24]. This reaction could be exploited to determine long-term prognosis and treatment response on MR spectroscopy but still needs validation. Magnetic iron oxide nanoparticles or ultra-small particles of iron oxides may demonstrate a potential in detecting malignant pelvic lymph nodes, but these particles are not widely available [25]. | 69459 |
acrac_69459_3 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Contrast-enhanced US could be useful to diagnose the depth of myometrial invasion using the arcuate vascular plexus involvement as a marker, with the diagnostic accuracy for determining the myometrium infiltration depth was 85.3%; however, this needs further validation [31]. FDG-PET/MRI is emerging as a hybrid imaging modality that combines the functional ability of PET with the morphological high soft-tissue contrast provided by MRI. Although there is a paucity of literature on the role of FDG-PET/MRI for the initial staging and suspected recurrence in patients with EC, studies assessing local staging, lymph node involvement, and distant metastases in gynecological malignancies have found that FDG-PET/MRI is equivalent or outperforms FDG-PET/CT. Queiroz et al [32] studied 26 patients with gynecological malignancies (including four ECs) and found that PET/MRI had improved delineation compared to PET/CT for 2 of 3 ECs and 6 of 7 cervical cancers. These authors found no difference in the detection of regional lymph node involvement and abdominal metastases between the two modalities. More recently, a meta-analysis that comprised 7 studies and 216 patients with a variety of gynecological malignancies showed excellent diagnostic performance of FDG-PET/MRI to assess the primary tumor, nodal staging, and recurrence in patients with gynecological malignancies including EC [33]. In a study of 81 patients with proven recurrence of gynecological malignancy, PET/MRI achieved a lesion- based accuracy of 94% compared to 92% for PET/CT [34]. A meta-analysis (7 studies, 257 patients, 695 lesions) that evaluated the diagnostic value of FDG-PET/MRI for restaging patients with suspected recurrence of gynecological malignancies reported the pooled sensitivity and specificity on a patient-based analysis to be 0.96 and 0.95, respectively, and on a lesion-based analysis 0.99 and 0.94, respectively [35]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Contrast-enhanced US could be useful to diagnose the depth of myometrial invasion using the arcuate vascular plexus involvement as a marker, with the diagnostic accuracy for determining the myometrium infiltration depth was 85.3%; however, this needs further validation [31]. FDG-PET/MRI is emerging as a hybrid imaging modality that combines the functional ability of PET with the morphological high soft-tissue contrast provided by MRI. Although there is a paucity of literature on the role of FDG-PET/MRI for the initial staging and suspected recurrence in patients with EC, studies assessing local staging, lymph node involvement, and distant metastases in gynecological malignancies have found that FDG-PET/MRI is equivalent or outperforms FDG-PET/CT. Queiroz et al [32] studied 26 patients with gynecological malignancies (including four ECs) and found that PET/MRI had improved delineation compared to PET/CT for 2 of 3 ECs and 6 of 7 cervical cancers. These authors found no difference in the detection of regional lymph node involvement and abdominal metastases between the two modalities. More recently, a meta-analysis that comprised 7 studies and 216 patients with a variety of gynecological malignancies showed excellent diagnostic performance of FDG-PET/MRI to assess the primary tumor, nodal staging, and recurrence in patients with gynecological malignancies including EC [33]. In a study of 81 patients with proven recurrence of gynecological malignancy, PET/MRI achieved a lesion- based accuracy of 94% compared to 92% for PET/CT [34]. A meta-analysis (7 studies, 257 patients, 695 lesions) that evaluated the diagnostic value of FDG-PET/MRI for restaging patients with suspected recurrence of gynecological malignancies reported the pooled sensitivity and specificity on a patient-based analysis to be 0.96 and 0.95, respectively, and on a lesion-based analysis 0.99 and 0.94, respectively [35]. | 69459 |
acrac_69459_4 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Discussion of Procedures by Variant Variant 1: Initial staging of pretreatment endometrial cancer; assessment of local tumor extension for all tumor grades. Currently there is little consensus on the role of pelvic imaging in the preoperative staging of EC, with practices differing widely across centers [36]. However, when assessment of local tumour extent during initial staging is clinically indicated, this variant addresses the evidence regarding the appropriate use of the different imaging modalities. The NCCN 2020 guidelines advise MRI for initial workup as follows: to establish the origin of the tumor (endocervical versus endometrial), assess local disease extent, and exclude myometrial invasion for fertility sparing treatment [23]. In 2016, a European multidisciplinary expert panel consensus meeting on EC suggested that MRI may be useful to assess myometrial invasion in centers in which the need for lymph node dissection is based on the preoperative stratification into low-, intermediate-, or high-risk groups [37]. Preoperative risk stratification is important, because currently there is no imaging modality that can replace surgical staging, given the inability of preoperative imaging to identify small lymph node metastases, which if present will require adjuvant therapy. However, MRI is accurate at identifying two surrogate markers of lymph node metastases (eg, deep myometrial invasion and cervical stromal involvement) [38]. In the absence of these and with low-grade tumors, the risk of lymph node metastases is low [39]. In the presence of these surrogate markers, the likelihood of lymph node metastases is high enough for full surgical staging by gynecological surgeons even for low-grade tumors [9]. The role of sentinel lymph node sampling versus complete lymphadenectomy in this subgroup of patients requires further investigation [13]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Discussion of Procedures by Variant Variant 1: Initial staging of pretreatment endometrial cancer; assessment of local tumor extension for all tumor grades. Currently there is little consensus on the role of pelvic imaging in the preoperative staging of EC, with practices differing widely across centers [36]. However, when assessment of local tumour extent during initial staging is clinically indicated, this variant addresses the evidence regarding the appropriate use of the different imaging modalities. The NCCN 2020 guidelines advise MRI for initial workup as follows: to establish the origin of the tumor (endocervical versus endometrial), assess local disease extent, and exclude myometrial invasion for fertility sparing treatment [23]. In 2016, a European multidisciplinary expert panel consensus meeting on EC suggested that MRI may be useful to assess myometrial invasion in centers in which the need for lymph node dissection is based on the preoperative stratification into low-, intermediate-, or high-risk groups [37]. Preoperative risk stratification is important, because currently there is no imaging modality that can replace surgical staging, given the inability of preoperative imaging to identify small lymph node metastases, which if present will require adjuvant therapy. However, MRI is accurate at identifying two surrogate markers of lymph node metastases (eg, deep myometrial invasion and cervical stromal involvement) [38]. In the absence of these and with low-grade tumors, the risk of lymph node metastases is low [39]. In the presence of these surrogate markers, the likelihood of lymph node metastases is high enough for full surgical staging by gynecological surgeons even for low-grade tumors [9]. The role of sentinel lymph node sampling versus complete lymphadenectomy in this subgroup of patients requires further investigation [13]. | 69459 |
acrac_69459_5 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | High-grade tumors are at risk for extrauterine spread and therefore warrant full surgical staging by gynecological surgeons. The role of imaging in this subgroup may be to identify extrauterine metastases or spread, which helps Evaluation and Follow-Up of Endometrial Cancer plan the surgical approach (eg, minimally invasive surgery versus laparotomy). Laparotomy is the preferred approach when involvement of pelvic or abdominal organs are suspected. MRI Pelvis Pelvic MRI has long been established as a valuable imaging method in the preoperative staging of EC [45-49]. MRI is preferred over US or CT for pretreatment evaluation because it allows the most accurate evaluation of the extent of pelvic tumor. A meta-analysis showed that the efficacy of contrast-enhanced MRI is significantly better than that of noncontrast MRI and US, and tended toward better results than CT, in evaluating the depth of myometrial invasion in patients with EC [50]. One study found that high-frequency TVUS has similar diagnostic accuracy in the evaluation of both tumor extension into the cervix (92% for high-frequency TVUS versus 85% for MRI) and myometrial invasion (84% for high-frequency TVUS versus 82% for MRI) [51]. However, in patients with an elevated body mass index, in the presence of myomas or adenomyosis, in the setting of bulky tumors, and in the presence of a vertical or retroverted uterine corpus, evaluation of the EC is difficult with TVUS [51]. Disruption of the low signal intensity junctional zone on the T2-weighted images (T2WI) indicates the presence of myometrial invasion. Deep myometrial invasion is diagnosed when the intermediate signal intensity of the tumor involves at least 50% of the myometrial thickness on the T2WI. Dynamic contrast-enhanced MRI performs significantly better than unenhanced MRI for evaluating the depth of myometrial invasion, which is best demonstrated after 50 to 120 seconds postcontrast injection [50,52]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. High-grade tumors are at risk for extrauterine spread and therefore warrant full surgical staging by gynecological surgeons. The role of imaging in this subgroup may be to identify extrauterine metastases or spread, which helps Evaluation and Follow-Up of Endometrial Cancer plan the surgical approach (eg, minimally invasive surgery versus laparotomy). Laparotomy is the preferred approach when involvement of pelvic or abdominal organs are suspected. MRI Pelvis Pelvic MRI has long been established as a valuable imaging method in the preoperative staging of EC [45-49]. MRI is preferred over US or CT for pretreatment evaluation because it allows the most accurate evaluation of the extent of pelvic tumor. A meta-analysis showed that the efficacy of contrast-enhanced MRI is significantly better than that of noncontrast MRI and US, and tended toward better results than CT, in evaluating the depth of myometrial invasion in patients with EC [50]. One study found that high-frequency TVUS has similar diagnostic accuracy in the evaluation of both tumor extension into the cervix (92% for high-frequency TVUS versus 85% for MRI) and myometrial invasion (84% for high-frequency TVUS versus 82% for MRI) [51]. However, in patients with an elevated body mass index, in the presence of myomas or adenomyosis, in the setting of bulky tumors, and in the presence of a vertical or retroverted uterine corpus, evaluation of the EC is difficult with TVUS [51]. Disruption of the low signal intensity junctional zone on the T2-weighted images (T2WI) indicates the presence of myometrial invasion. Deep myometrial invasion is diagnosed when the intermediate signal intensity of the tumor involves at least 50% of the myometrial thickness on the T2WI. Dynamic contrast-enhanced MRI performs significantly better than unenhanced MRI for evaluating the depth of myometrial invasion, which is best demonstrated after 50 to 120 seconds postcontrast injection [50,52]. | 69459 |
acrac_69459_6 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Inner layers of the junctional zone typically enhance on arterial phase [24]. Demonstration of an undisrupted enhancing subendometrial line signifies lack of myometrial involvement [24]. This is a useful sign to rule-out myometrial invasion in postmenopausal patients whose junctional zone is otherwise not well discernible on T2WI [53]. In addition, absence of myometrial invasion as shown by an intact subendometrial line of enhancement is particularly relevant for women wishing to consider fertility-preserving treatment options. EC shows restricted diffusion and appears hyperintense on DWI relative to surrounding myometrium. One study showed that the apparent diffusion coefficient (ADC) value of the peritumoral tissue achieved an accuracy similar to the qualitative assessment by experienced readers, 83% versus 76%, respectively [54]. A meta-analysis revealed that the pooled sensitivity and specificity of DWI for detecting deep myometrial invasion were 80.9% and 85.9%, respectively [55]. It was also reported that the diagnostic capability of DWI for deep myometrial invasion improved when it was combined with T2WI (pooled sensitivity: 85.8%, pooled specificity: 94.7%). These results are comparable or superior to the contrast-enhanced MRI, thus DWI can be a potential alternative to patients with compromised kidney functions, in which contrast is contraindicated [46,47,56-61]. An erroneous MRI assessment in evaluating the depth of myometrial invasion can sometimes be caused by a polypoid tumor compressing the myometrium or in the presence of adenomyosis and leiomyomas. Evaluation and Follow-Up of Endometrial Cancer Studies have not shown any added advantage of using 3T versus 1.5T, and results are comparable for both 3T and 1.5T systems. Advantages of 3T imaging includes improved spectral separation as well as increased signal-to-noise ratios, which can be exploited to acquire images with a higher spatial resolution or decreased image acquisition times. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Inner layers of the junctional zone typically enhance on arterial phase [24]. Demonstration of an undisrupted enhancing subendometrial line signifies lack of myometrial involvement [24]. This is a useful sign to rule-out myometrial invasion in postmenopausal patients whose junctional zone is otherwise not well discernible on T2WI [53]. In addition, absence of myometrial invasion as shown by an intact subendometrial line of enhancement is particularly relevant for women wishing to consider fertility-preserving treatment options. EC shows restricted diffusion and appears hyperintense on DWI relative to surrounding myometrium. One study showed that the apparent diffusion coefficient (ADC) value of the peritumoral tissue achieved an accuracy similar to the qualitative assessment by experienced readers, 83% versus 76%, respectively [54]. A meta-analysis revealed that the pooled sensitivity and specificity of DWI for detecting deep myometrial invasion were 80.9% and 85.9%, respectively [55]. It was also reported that the diagnostic capability of DWI for deep myometrial invasion improved when it was combined with T2WI (pooled sensitivity: 85.8%, pooled specificity: 94.7%). These results are comparable or superior to the contrast-enhanced MRI, thus DWI can be a potential alternative to patients with compromised kidney functions, in which contrast is contraindicated [46,47,56-61]. An erroneous MRI assessment in evaluating the depth of myometrial invasion can sometimes be caused by a polypoid tumor compressing the myometrium or in the presence of adenomyosis and leiomyomas. Evaluation and Follow-Up of Endometrial Cancer Studies have not shown any added advantage of using 3T versus 1.5T, and results are comparable for both 3T and 1.5T systems. Advantages of 3T imaging includes improved spectral separation as well as increased signal-to-noise ratios, which can be exploited to acquire images with a higher spatial resolution or decreased image acquisition times. | 69459 |
acrac_69459_7 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | However, 3T images typically have more susceptibility and chemical shift artifacts and greater image inhomogeneity on T2WI [67,68]. US Pelvis Transvaginal In a study of 169 consecutive patients with EC, TVUS achieved a 79.5% sensitivity and a 89.6% specificity for detecting deep myometrial invasion were 82% and 81%, respectively [69]. A prospective collaborative trial comparing MRI and US, reported that the accuracy of US is comparable to that provided by MRI [51]. However, US has reported accuracies varying between 77% and 91% [50,51]. A more recent study found that MRI showed greater accuracy than 3-D TVUS or 2-D TVUS (83%, 71%, and 75%, respectively) for myometrial involvement [28]. US is limited in the setting of concomitant benign disease (eg, leiomyomas or adenomyosis) and also for large lesions because of the limited depth of penetration of TVUS. In addition, there are insufficient reports about the benefit of TVUS in predicting cervical extension, parametrical invasion, or lymphadenopathy. Studies have shown that contrast-enhanced US could be useful to diagnose the depth of myometrial invasion using the arcuate vascular plexus involvement as a marker; however, this needs further validation [31]. Variant 2: Pretreatment evaluation of endometrial cancer; assessment of lymph node and distant metastasis for low-grade tumor (Type I, grade 1, 2). Most patients with low-grade disease are at low risk of lymph node and distant metastases. In the largest series to date on grade 1 ECs, the incidence of pelvic lymph node involvement, pelvic metastasis, and distant metastasis specific to grade 1 tumors is estimated at 3.3%, 4.6%, and 2.4%, respectively [70]. CT Chest, Abdomen, and Pelvis Contrast-enhanced CT of the abdomen and pelvis may be employed preoperatively for the detection of lymph node metastases in EC. However, the reported sensitivity of contrast-enhanced CT for pelvic and para-aortic lymphadenopathy is only 29% to 52% [71,72]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. However, 3T images typically have more susceptibility and chemical shift artifacts and greater image inhomogeneity on T2WI [67,68]. US Pelvis Transvaginal In a study of 169 consecutive patients with EC, TVUS achieved a 79.5% sensitivity and a 89.6% specificity for detecting deep myometrial invasion were 82% and 81%, respectively [69]. A prospective collaborative trial comparing MRI and US, reported that the accuracy of US is comparable to that provided by MRI [51]. However, US has reported accuracies varying between 77% and 91% [50,51]. A more recent study found that MRI showed greater accuracy than 3-D TVUS or 2-D TVUS (83%, 71%, and 75%, respectively) for myometrial involvement [28]. US is limited in the setting of concomitant benign disease (eg, leiomyomas or adenomyosis) and also for large lesions because of the limited depth of penetration of TVUS. In addition, there are insufficient reports about the benefit of TVUS in predicting cervical extension, parametrical invasion, or lymphadenopathy. Studies have shown that contrast-enhanced US could be useful to diagnose the depth of myometrial invasion using the arcuate vascular plexus involvement as a marker; however, this needs further validation [31]. Variant 2: Pretreatment evaluation of endometrial cancer; assessment of lymph node and distant metastasis for low-grade tumor (Type I, grade 1, 2). Most patients with low-grade disease are at low risk of lymph node and distant metastases. In the largest series to date on grade 1 ECs, the incidence of pelvic lymph node involvement, pelvic metastasis, and distant metastasis specific to grade 1 tumors is estimated at 3.3%, 4.6%, and 2.4%, respectively [70]. CT Chest, Abdomen, and Pelvis Contrast-enhanced CT of the abdomen and pelvis may be employed preoperatively for the detection of lymph node metastases in EC. However, the reported sensitivity of contrast-enhanced CT for pelvic and para-aortic lymphadenopathy is only 29% to 52% [71,72]. | 69459 |
acrac_69459_8 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | If distant metastatic disease is clinically suspected, preoperative assessment of metastatic disease with contrast-enhanced CT is indicated. However, most patients with low-grade disease are at low risk of lymph node and distant metastases. Thus, this group does not require a routine pretreatment evaluation for distant metastases by CT imaging. FDG-PET/CT Skull Base to Mid-Thigh The role of PET in EC imaging is evolving. Recently, a meta-analysis reported that the overall pooled sensitivity, specificity, and accuracy of using FDG-PET/CT for detection of lymph node metastasis in EC was 72.0%, 94.0%, and 88.0%, respectively [73]. Although this meta-analysis found the overall sensitivity of FDG-PET/CT to be moderate for the detection of lymph node metastasis in EC, it compares favorably with the reported sensitivities for lymph node metastasis detection by conventional MRI and CT. However, because 45% of ECs are grade 1 and not particularly FDG-avid, the routine use of FDG-PET in preoperative staging in early stage disease is not recommended, but FDG-PET may be used in patients in which distant metastases is clinically suspected [19,74]. Lymphangiography Pelvis Lymphangiography pelvis is not helpful for evaluating cancer of the endometrium because 1) it is invasive, and 2) its performance for assessing pelvic lymph nodes is not reproducible and the accuracy is slightly inferior to that of CT and MRI [75]. MRI Abdomen If distant metastasis to other abdominal organs (eg, liver) is clinically suspected, abdominal MRI or CT may be performed. However, patients in this group are at low risk for distant metastases [80]. US Pelvis Transabdominal The combination of morphological and vascular patterns of lymph nodes using transabdominal US can be used to differentiate metastatic from normal or reactive nodes [81]. However, visualization of retroperitoneal or iliac lymph nodes can be limited using US because of patient body habitus and overlying bowel gas. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. If distant metastatic disease is clinically suspected, preoperative assessment of metastatic disease with contrast-enhanced CT is indicated. However, most patients with low-grade disease are at low risk of lymph node and distant metastases. Thus, this group does not require a routine pretreatment evaluation for distant metastases by CT imaging. FDG-PET/CT Skull Base to Mid-Thigh The role of PET in EC imaging is evolving. Recently, a meta-analysis reported that the overall pooled sensitivity, specificity, and accuracy of using FDG-PET/CT for detection of lymph node metastasis in EC was 72.0%, 94.0%, and 88.0%, respectively [73]. Although this meta-analysis found the overall sensitivity of FDG-PET/CT to be moderate for the detection of lymph node metastasis in EC, it compares favorably with the reported sensitivities for lymph node metastasis detection by conventional MRI and CT. However, because 45% of ECs are grade 1 and not particularly FDG-avid, the routine use of FDG-PET in preoperative staging in early stage disease is not recommended, but FDG-PET may be used in patients in which distant metastases is clinically suspected [19,74]. Lymphangiography Pelvis Lymphangiography pelvis is not helpful for evaluating cancer of the endometrium because 1) it is invasive, and 2) its performance for assessing pelvic lymph nodes is not reproducible and the accuracy is slightly inferior to that of CT and MRI [75]. MRI Abdomen If distant metastasis to other abdominal organs (eg, liver) is clinically suspected, abdominal MRI or CT may be performed. However, patients in this group are at low risk for distant metastases [80]. US Pelvis Transabdominal The combination of morphological and vascular patterns of lymph nodes using transabdominal US can be used to differentiate metastatic from normal or reactive nodes [81]. However, visualization of retroperitoneal or iliac lymph nodes can be limited using US because of patient body habitus and overlying bowel gas. | 69459 |
acrac_69459_9 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Suspicious inguinal lymph nodes can be readily assessed by US and biopsied as needed. US Abdomen Transabdominal US can be used to detect abdominal organ metastasis. However, most patients with low-grade disease are at low risk of lymph node and distant metastases and thus may not require routine pretreatment evaluation by US imaging. Variant 3: Initial staging of pretreatment endometrial cancer; assessment of lymph node and distant metastasis for high-grade tumor (Type I, grade 3 and Type II). In a recent series, nodal metastases have been depicted in up to 29% of patients in intermediate- to high-risk categories [82]. In a study of 55 patients with EC with distant metastasis, 47.2% of patients had a type II tumor [83]. CT Chest, Abdomen, and Pelvis Contrast-enhanced CT of the abdomen and pelvis may be employed preoperatively for the detection of lymph node metastases in this group. However, the reported sensitivity of contrast-enhanced CT for pelvic and para-aortic lymphadenopathy is only 30% to 57%; meanwhile, the reported specificity of contrast-enhanced CT is 92% to 98% [41,71,72]. If distant metastatic disease is clinically suspected, preoperative assessment of metastatic disease with contrast-enhanced CT is indicated [37]. Lymphangiography Pelvis Lymphangiography pelvis is not recommended for evaluating cancer of the endometrium because 1) it is invasive, and 2) its performance for assessing pelvic lymph nodes is not reproducible and the accuracy is slightly inferior to that of CT and MRI even when performed optimally [75]. MRI Abdomen If distant metastasis to other abdominal organs (eg, liver) is clinically suspected, abdominal MRI or CT may be performed. US Pelvis Transabdominal The combination of morphological and vascular patterns of lymph nodes using transabdominal US can be used to differentiate metastatic from normal or reactive nodes [81]. However, there is insufficient data to allow comparison of this procedure to CT or MRI. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Suspicious inguinal lymph nodes can be readily assessed by US and biopsied as needed. US Abdomen Transabdominal US can be used to detect abdominal organ metastasis. However, most patients with low-grade disease are at low risk of lymph node and distant metastases and thus may not require routine pretreatment evaluation by US imaging. Variant 3: Initial staging of pretreatment endometrial cancer; assessment of lymph node and distant metastasis for high-grade tumor (Type I, grade 3 and Type II). In a recent series, nodal metastases have been depicted in up to 29% of patients in intermediate- to high-risk categories [82]. In a study of 55 patients with EC with distant metastasis, 47.2% of patients had a type II tumor [83]. CT Chest, Abdomen, and Pelvis Contrast-enhanced CT of the abdomen and pelvis may be employed preoperatively for the detection of lymph node metastases in this group. However, the reported sensitivity of contrast-enhanced CT for pelvic and para-aortic lymphadenopathy is only 30% to 57%; meanwhile, the reported specificity of contrast-enhanced CT is 92% to 98% [41,71,72]. If distant metastatic disease is clinically suspected, preoperative assessment of metastatic disease with contrast-enhanced CT is indicated [37]. Lymphangiography Pelvis Lymphangiography pelvis is not recommended for evaluating cancer of the endometrium because 1) it is invasive, and 2) its performance for assessing pelvic lymph nodes is not reproducible and the accuracy is slightly inferior to that of CT and MRI even when performed optimally [75]. MRI Abdomen If distant metastasis to other abdominal organs (eg, liver) is clinically suspected, abdominal MRI or CT may be performed. US Pelvis Transabdominal The combination of morphological and vascular patterns of lymph nodes using transabdominal US can be used to differentiate metastatic from normal or reactive nodes [81]. However, there is insufficient data to allow comparison of this procedure to CT or MRI. | 69459 |
acrac_69459_10 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Nevertheless, visualization of retroperitoneal or iliac lymph nodes is frequently limited using US because of patient body habitus and overlying bowel gas. Suspicious inguinal lymph nodes can be readily assessed by US and biopsied as needed. US Abdomen If solid abdominal organ metastatic disease is clinically suspected, then transabdominal US may be used [81]. Variant 4: Surveillance of asymptomatic patients with treated low- or intermediate-risk endometrial cancer. Recurrence rates for low- or intermediate-risk patients with EC are infrequent. Therefore, a recent review of posttreatment surveillance and diagnosis of recurrence in women with gynecologic cancers sponsored by the Society of Gynecologic Oncology recommends that radiologic evaluation be used only to investigate suspicion of recurrent disease because of symptoms or physical exam and not for routine surveillance after treatment [80]. MRI Pelvis There currently is not sufficient evidence in the literature to recommend routine surveillance by MRI for patients with low- or intermediate-risk EC [80]. MRI Abdomen MRI may also be used for assessment of metastasis of the liver, adrenals, brain, bones, and soft-tissue when metastases are clinically suspected and need further investigation. However, there is insufficient data to support the routine use of MRI for surveillance of asymptomatic patients [80]. CT Chest, Abdomen, and Pelvis A review of the literature found that only 5% to 21% of asymptomatic recurrences were detected by CT [87]. Another study reported that the role of CT scanning for asymptomatic patients is not warranted because survival of patients with disease that is detected on CT scan, compared with clinical examination, did not differ significantly [88]. Therefore, the use of routine CT scan is not useful for disease surveillance [19,89]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Nevertheless, visualization of retroperitoneal or iliac lymph nodes is frequently limited using US because of patient body habitus and overlying bowel gas. Suspicious inguinal lymph nodes can be readily assessed by US and biopsied as needed. US Abdomen If solid abdominal organ metastatic disease is clinically suspected, then transabdominal US may be used [81]. Variant 4: Surveillance of asymptomatic patients with treated low- or intermediate-risk endometrial cancer. Recurrence rates for low- or intermediate-risk patients with EC are infrequent. Therefore, a recent review of posttreatment surveillance and diagnosis of recurrence in women with gynecologic cancers sponsored by the Society of Gynecologic Oncology recommends that radiologic evaluation be used only to investigate suspicion of recurrent disease because of symptoms or physical exam and not for routine surveillance after treatment [80]. MRI Pelvis There currently is not sufficient evidence in the literature to recommend routine surveillance by MRI for patients with low- or intermediate-risk EC [80]. MRI Abdomen MRI may also be used for assessment of metastasis of the liver, adrenals, brain, bones, and soft-tissue when metastases are clinically suspected and need further investigation. However, there is insufficient data to support the routine use of MRI for surveillance of asymptomatic patients [80]. CT Chest, Abdomen, and Pelvis A review of the literature found that only 5% to 21% of asymptomatic recurrences were detected by CT [87]. Another study reported that the role of CT scanning for asymptomatic patients is not warranted because survival of patients with disease that is detected on CT scan, compared with clinical examination, did not differ significantly [88]. Therefore, the use of routine CT scan is not useful for disease surveillance [19,89]. | 69459 |
acrac_69459_11 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Radiography Chest Chest radiographs have been advocated for the detection of asymptomatic chest recurrences, often on a semi-annual or annual basis. However, the rate of detection for asymptomatic chest recurrences found on chest radiographs ranges only from 0% to 20% [87,90]. Thus, this procedure may not be appropriate for this group. US Pelvis Transvaginal Because many of the recurrences are detected during the physical examination, the use of routine pelvic US is not advocated [21,87]. US Pelvis Transabdominal Because many of the recurrences are detected during the physical examination, the use of routine pelvic US is not advocated [21,87]. US Abdomen Because many of the recurrences are detected during the physical examination the use of abdominal US is not advocated [21,87]. Evaluation and Follow-Up of Endometrial Cancer Variant 5: Surveillance of asymptomatic patients with treated high-risk endometrial cancer. Most patients are cured following primary treatment; however, approximately 25% to 30% of patients in this subgroup may develop recurrent disease [91]. Typical metastatic sites of recurrent EC are local pelvic recurrence, pelvic and para-aortic lymph nodes, peritoneum, and lungs [17]. Atypical metastatic sites are extra-abdominal lymph nodes, liver, adrenals, brain, bones, and soft-tissue [17]. Vaginal bleeding is a common symptom of a local recurrence. In patients diagnosed with a distant recurrence, symptoms such as coughing, pain, lethargy, weight loss, or headaches are present in up to 70% of cases [19,20]. In one reported study, the combination of physical examination alone or in combination with symptoms resulted in detection rates of recurrence that exceeded 80% [21]. CT Chest, Abdomen, and Pelvis The evidence supporting routine CT surveillance following EC is insufficient. Even in type II EC, CT scans detected only 15% of recurrences [92]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Radiography Chest Chest radiographs have been advocated for the detection of asymptomatic chest recurrences, often on a semi-annual or annual basis. However, the rate of detection for asymptomatic chest recurrences found on chest radiographs ranges only from 0% to 20% [87,90]. Thus, this procedure may not be appropriate for this group. US Pelvis Transvaginal Because many of the recurrences are detected during the physical examination, the use of routine pelvic US is not advocated [21,87]. US Pelvis Transabdominal Because many of the recurrences are detected during the physical examination, the use of routine pelvic US is not advocated [21,87]. US Abdomen Because many of the recurrences are detected during the physical examination the use of abdominal US is not advocated [21,87]. Evaluation and Follow-Up of Endometrial Cancer Variant 5: Surveillance of asymptomatic patients with treated high-risk endometrial cancer. Most patients are cured following primary treatment; however, approximately 25% to 30% of patients in this subgroup may develop recurrent disease [91]. Typical metastatic sites of recurrent EC are local pelvic recurrence, pelvic and para-aortic lymph nodes, peritoneum, and lungs [17]. Atypical metastatic sites are extra-abdominal lymph nodes, liver, adrenals, brain, bones, and soft-tissue [17]. Vaginal bleeding is a common symptom of a local recurrence. In patients diagnosed with a distant recurrence, symptoms such as coughing, pain, lethargy, weight loss, or headaches are present in up to 70% of cases [19,20]. In one reported study, the combination of physical examination alone or in combination with symptoms resulted in detection rates of recurrence that exceeded 80% [21]. CT Chest, Abdomen, and Pelvis The evidence supporting routine CT surveillance following EC is insufficient. Even in type II EC, CT scans detected only 15% of recurrences [92]. | 69459 |
acrac_69459_12 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Chest CT with or without intravenous (IV) contrast may be obtained as a part of posttherapy surveillance in selected high-risk groups or patients with an advanced FIGO stage [81,83,84]. MRI Pelvis Recurrent tumor appears as a mass with high signal intensity on T2WI and intensely enhances following IV contrast administration [93]. MRI has a role in the evaluation of surgical resectability if the pelvis is the sole site of recurrence [36]. However, there is insufficient data to support the routine use of MRI for surveillance of asymptomatic patients [80]. MRI Abdomen MRI may also be used for assessment of metastasis of the liver, adrenals, brain, bones, and soft-tissue when metastases are clinically suspected and need further investigation. However, there is insufficient data to support the routine use of MRI for surveillance of asymptomatic patients [80]. Radiography Chest Chest radiographs have been advocated for the detection of asymptomatic chest recurrences, often on a semi-annual or annual basis. However, the rate of detection for asymptomatic chest recurrences found on chest radiographs ranges only from 0% to 20% [87,90]. Thus, this procedure may be useful when lung metastases are clinically suspected. US Pelvis Transvaginal Because many of the recurrences are detected during physical examination, the use of routine pelvic is not advocated [21,87]. US Pelvis Transabdominal Because many of the recurrences are detected during the physical examination, the use of routine pelvic US is not advocated [21,87]. US Abdomen Because many of the recurrences are detected during the physical examination, the use of abdominal US is not advocated [21,87]. Variant 6: Posttherapy evaluation of clinically suspected recurrence of known endometrial cancer. Most patients are cured following primary treatment, and approximately 25% to 30% of patients with high-risk EC may develop recurrent disease [91]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Chest CT with or without intravenous (IV) contrast may be obtained as a part of posttherapy surveillance in selected high-risk groups or patients with an advanced FIGO stage [81,83,84]. MRI Pelvis Recurrent tumor appears as a mass with high signal intensity on T2WI and intensely enhances following IV contrast administration [93]. MRI has a role in the evaluation of surgical resectability if the pelvis is the sole site of recurrence [36]. However, there is insufficient data to support the routine use of MRI for surveillance of asymptomatic patients [80]. MRI Abdomen MRI may also be used for assessment of metastasis of the liver, adrenals, brain, bones, and soft-tissue when metastases are clinically suspected and need further investigation. However, there is insufficient data to support the routine use of MRI for surveillance of asymptomatic patients [80]. Radiography Chest Chest radiographs have been advocated for the detection of asymptomatic chest recurrences, often on a semi-annual or annual basis. However, the rate of detection for asymptomatic chest recurrences found on chest radiographs ranges only from 0% to 20% [87,90]. Thus, this procedure may be useful when lung metastases are clinically suspected. US Pelvis Transvaginal Because many of the recurrences are detected during physical examination, the use of routine pelvic is not advocated [21,87]. US Pelvis Transabdominal Because many of the recurrences are detected during the physical examination, the use of routine pelvic US is not advocated [21,87]. US Abdomen Because many of the recurrences are detected during the physical examination, the use of abdominal US is not advocated [21,87]. Variant 6: Posttherapy evaluation of clinically suspected recurrence of known endometrial cancer. Most patients are cured following primary treatment, and approximately 25% to 30% of patients with high-risk EC may develop recurrent disease [91]. | 69459 |
acrac_69459_13 | Pretreatment Evaluation and Follow Up of Endometrial Cancer | Typical metastatic sites of recurrent EC are local pelvic recurrence, pelvic and para-aortic nodes, peritoneum, and lungs [17]. Atypical metastatic sites are extra-abdominal lymph nodes, liver, adrenals, brain, bones, and soft-tissue [17]. Vaginal bleeding is a common symptom of a local recurrence. In patients diagnosed with a distant recurrence, symptoms such as coughing, pain, lethargy, weight loss, or headaches are present in up to 70% of cases [19,20]. In one reported study, the combination of physical examination alone or in combination with symptoms resulted in detection rates of recurrence that exceeded 80% [21]. MRI Pelvis MRI may be indicated in a patient clinically suspected to have local recurrence or distant metastasis [94]. Recurrent tumor appears as a mass with high signal intensity on T2WI and enhances intensely following IV contrast administration [93]. MRI has a role in the evaluation of surgical resectability if the pelvis is the sole site of recurrence [36,95]. Evaluation and Follow-Up of Endometrial Cancer MRI Abdomen MRI may be indicated in patient clinically suspected to have local recurrence or distant metastasis [94]. Recurrent tumor appears as a mass with high signal intensity on T2WI and enhances intensely following IV contrast administration [93]. MRI may be used for assessment of metastasis of the liver, adrenals, brain, bones, and soft tissue when metastases are clinically suspected and require further investigation. CT Chest, Abdomen, and Pelvis CT may play a role in the evaluation of patients with symptoms suggestive of recurrence [71]. A study reported that 45 asymptomatic women had routine CT scans, and recurrence was diagnosed by CT in only 2 (4.4%); whereas, 37 symptomatic women had CT scans for suspicion of recurrence, and it was confirmed by CT in 17 (46%) [71]. | Pretreatment Evaluation and Follow Up of Endometrial Cancer. Typical metastatic sites of recurrent EC are local pelvic recurrence, pelvic and para-aortic nodes, peritoneum, and lungs [17]. Atypical metastatic sites are extra-abdominal lymph nodes, liver, adrenals, brain, bones, and soft-tissue [17]. Vaginal bleeding is a common symptom of a local recurrence. In patients diagnosed with a distant recurrence, symptoms such as coughing, pain, lethargy, weight loss, or headaches are present in up to 70% of cases [19,20]. In one reported study, the combination of physical examination alone or in combination with symptoms resulted in detection rates of recurrence that exceeded 80% [21]. MRI Pelvis MRI may be indicated in a patient clinically suspected to have local recurrence or distant metastasis [94]. Recurrent tumor appears as a mass with high signal intensity on T2WI and enhances intensely following IV contrast administration [93]. MRI has a role in the evaluation of surgical resectability if the pelvis is the sole site of recurrence [36,95]. Evaluation and Follow-Up of Endometrial Cancer MRI Abdomen MRI may be indicated in patient clinically suspected to have local recurrence or distant metastasis [94]. Recurrent tumor appears as a mass with high signal intensity on T2WI and enhances intensely following IV contrast administration [93]. MRI may be used for assessment of metastasis of the liver, adrenals, brain, bones, and soft tissue when metastases are clinically suspected and require further investigation. CT Chest, Abdomen, and Pelvis CT may play a role in the evaluation of patients with symptoms suggestive of recurrence [71]. A study reported that 45 asymptomatic women had routine CT scans, and recurrence was diagnosed by CT in only 2 (4.4%); whereas, 37 symptomatic women had CT scans for suspicion of recurrence, and it was confirmed by CT in 17 (46%) [71]. | 69459 |
acrac_69376_0 | Penetrating Trauma Lower Abdomen and Pelvis | Most of the contemporary literature concerning urethral injury deals with posterior urethral injuries associated with pelvic fractures, which are most commonly due to motor vehicle accidents [4]. In male patients with suspected penetrating trauma of the urethra, the anterior urethra is most often affected. Penetrating injury to the anterior urethra is typically surgically repaired in the acute setting [1,2]. Evaluating the degree of disruption of the anterior urethra is an important factor in operative planning. Penetrating posterior urethral injury is treated with immediate exploration via a retropubic approach and primary repair; if coexisting severe injuries preclude direct urethral repair initially, suprapubic diversion with delayed urethroplasty can be performed [1]. Retrograde urethrography (RUG) has traditionally been the standard diagnostic imaging method for evaluation of urethral trauma endorsed by the EAU and AUA [1-3]. Penetrating trauma of the female urethra is uncommon because of its anatomy and is typically diagnosed with urethroscopy [1]. aUniversity of Pittsburgh, Pittsburgh, Pennsylvania. bPanel Chair, University of Chicago, Chicago, Illinois. cPanel Vice-Chair, Duke University Medical Center, Durham, North Carolina. dMemorial Sloan Kettering Cancer Center, New York, New York. eMayo Clinic, Jacksonville, Florida. fMcGill University, Montreal, Quebec, Canada. gMayo Clinic, Rochester, Minnesota. hUrology Clinics of North Texas, Dallas, Texas; American Urological Association. iMaine Medical Center, Portland, Maine; American College of Emergency Physicians. jUPMC, Pittsburgh, Pennsylvania; American Urological Association. kCleveland Clinic, Cleveland, Ohio. lStanford University Medical Center, Stanford, California. mOttawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada. nNational Institutes of Health, Bethesda, Maryland. oThe University of Texas MD Anderson Cancer Center, Houston, Texas. | Penetrating Trauma Lower Abdomen and Pelvis. Most of the contemporary literature concerning urethral injury deals with posterior urethral injuries associated with pelvic fractures, which are most commonly due to motor vehicle accidents [4]. In male patients with suspected penetrating trauma of the urethra, the anterior urethra is most often affected. Penetrating injury to the anterior urethra is typically surgically repaired in the acute setting [1,2]. Evaluating the degree of disruption of the anterior urethra is an important factor in operative planning. Penetrating posterior urethral injury is treated with immediate exploration via a retropubic approach and primary repair; if coexisting severe injuries preclude direct urethral repair initially, suprapubic diversion with delayed urethroplasty can be performed [1]. Retrograde urethrography (RUG) has traditionally been the standard diagnostic imaging method for evaluation of urethral trauma endorsed by the EAU and AUA [1-3]. Penetrating trauma of the female urethra is uncommon because of its anatomy and is typically diagnosed with urethroscopy [1]. aUniversity of Pittsburgh, Pittsburgh, Pennsylvania. bPanel Chair, University of Chicago, Chicago, Illinois. cPanel Vice-Chair, Duke University Medical Center, Durham, North Carolina. dMemorial Sloan Kettering Cancer Center, New York, New York. eMayo Clinic, Jacksonville, Florida. fMcGill University, Montreal, Quebec, Canada. gMayo Clinic, Rochester, Minnesota. hUrology Clinics of North Texas, Dallas, Texas; American Urological Association. iMaine Medical Center, Portland, Maine; American College of Emergency Physicians. jUPMC, Pittsburgh, Pennsylvania; American Urological Association. kCleveland Clinic, Cleveland, Ohio. lStanford University Medical Center, Stanford, California. mOttawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada. nNational Institutes of Health, Bethesda, Maryland. oThe University of Texas MD Anderson Cancer Center, Houston, Texas. | 69376 |
acrac_69376_1 | Penetrating Trauma Lower Abdomen and Pelvis | pUniversity of Washington, Seattle Cancer Care Alliance, Seattle, Washington. qSpecialty Chair, University of Alabama at Birmingham, Birmingham, Alabama. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Types III and IV bladder injuries can be the result of penetrating pelvic injury. Extraperitoneal rupture represents approximately 60% of major bladder injuries that are due to blunt trauma [3,6]; the incidence of extraperitoneal versus intraperitoneal rupture that is due to penetrating bladder trauma is not known. Sandler et al [7] further subdivided extraperitoneal rupture into 2 groups. With simple extraperitoneal rupture, contrast extravasation is limited to the pelvic extraperitoneal space. With complex extraperitoneal rupture, contrast material extravasation may extend into the anterior abdominal wall, the penis, the scrotum, and the perineum. The presence of a complex extraperitoneal injury implies that the injury has disrupted the fascial boundaries of the pelvis. Such findings should not be mistaken as evidence of a coexisting urethral injury. A combined bladder injury (type IV) results when both intraperitoneal and extraperitoneal bladder injuries are present. Penetrating bladder injuries are typically repaired surgically in the acute setting unless coexisting life-threatening injuries are present [1]. | Penetrating Trauma Lower Abdomen and Pelvis. pUniversity of Washington, Seattle Cancer Care Alliance, Seattle, Washington. qSpecialty Chair, University of Alabama at Birmingham, Birmingham, Alabama. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Types III and IV bladder injuries can be the result of penetrating pelvic injury. Extraperitoneal rupture represents approximately 60% of major bladder injuries that are due to blunt trauma [3,6]; the incidence of extraperitoneal versus intraperitoneal rupture that is due to penetrating bladder trauma is not known. Sandler et al [7] further subdivided extraperitoneal rupture into 2 groups. With simple extraperitoneal rupture, contrast extravasation is limited to the pelvic extraperitoneal space. With complex extraperitoneal rupture, contrast material extravasation may extend into the anterior abdominal wall, the penis, the scrotum, and the perineum. The presence of a complex extraperitoneal injury implies that the injury has disrupted the fascial boundaries of the pelvis. Such findings should not be mistaken as evidence of a coexisting urethral injury. A combined bladder injury (type IV) results when both intraperitoneal and extraperitoneal bladder injuries are present. Penetrating bladder injuries are typically repaired surgically in the acute setting unless coexisting life-threatening injuries are present [1]. | 69376 |
acrac_69376_2 | Penetrating Trauma Lower Abdomen and Pelvis | orifice Urethral Injury Injuries to the male urethra have been traditionally classified into 2 main categories according to their mechanism of injury: 1) those associated with a fracture of the anterior pelvic arch (usually involving the membranous urethra) and 2) those occurring as the result of a straddle injury (usually involving the bulbous urethra); both of these types of male urethral injury are more commonly found after blunt trauma, but can also result from penetrating trauma. The penile urethra is injured less frequently than the bulbar and membranous segments of the urethra overall; however, the penile urethra is more commonly injured with penetrating trauma because of its entirely external location. Female urethral injuries are rare and are usually associated with pelvic fracture or vaginal laceration [2,9,11]. The rarity of female urethral injury is due to the relatively shorter length, internal location posterior to the osseous Discussion of Procedures by Variant Variant 1: Penetrating trauma, lower abdomen and pelvis. Suspected lower urinary tract trauma. Initial imaging. Radiography Pelvis There is no relevant literature regarding the use of radiographs in the evaluation of penetrating trauma to the lower urinary tract. Radiography of the pelvis plays an ancillary role by identifying radiopaque foreign bodies associated with penetrating injuries and in identifying pelvic fractures. Pelvic radiography can be combined with RUG. CT Pelvis with Bladder Contrast (CT Cystography) Schneider [12] stated that either retrograde cystography or CT is the diagnostic procedure of choice for a suspected bladder injury, and Horstman et al [13] found that both types of imaging examinations equally detected all types of bladder injury in blunt trauma patients. The authors indicated that contrast instillation during CT can provide the adequate bladder distention needed to demonstrate contrast extravasation from the injury site. | Penetrating Trauma Lower Abdomen and Pelvis. orifice Urethral Injury Injuries to the male urethra have been traditionally classified into 2 main categories according to their mechanism of injury: 1) those associated with a fracture of the anterior pelvic arch (usually involving the membranous urethra) and 2) those occurring as the result of a straddle injury (usually involving the bulbous urethra); both of these types of male urethral injury are more commonly found after blunt trauma, but can also result from penetrating trauma. The penile urethra is injured less frequently than the bulbar and membranous segments of the urethra overall; however, the penile urethra is more commonly injured with penetrating trauma because of its entirely external location. Female urethral injuries are rare and are usually associated with pelvic fracture or vaginal laceration [2,9,11]. The rarity of female urethral injury is due to the relatively shorter length, internal location posterior to the osseous Discussion of Procedures by Variant Variant 1: Penetrating trauma, lower abdomen and pelvis. Suspected lower urinary tract trauma. Initial imaging. Radiography Pelvis There is no relevant literature regarding the use of radiographs in the evaluation of penetrating trauma to the lower urinary tract. Radiography of the pelvis plays an ancillary role by identifying radiopaque foreign bodies associated with penetrating injuries and in identifying pelvic fractures. Pelvic radiography can be combined with RUG. CT Pelvis with Bladder Contrast (CT Cystography) Schneider [12] stated that either retrograde cystography or CT is the diagnostic procedure of choice for a suspected bladder injury, and Horstman et al [13] found that both types of imaging examinations equally detected all types of bladder injury in blunt trauma patients. The authors indicated that contrast instillation during CT can provide the adequate bladder distention needed to demonstrate contrast extravasation from the injury site. | 69376 |
acrac_69376_3 | Penetrating Trauma Lower Abdomen and Pelvis | Since then, CT cystography has become the first-line evaluation for bladder injury in the acute trauma setting [4]. This technique refers to the retrograde instillation of a minimum of 350 cc of diluted contrast media into the bladder, followed by axial and coronal CT images of the pelvis [6,14]. Unlike conventional cystography, no postdrainage CT images are needed. In a study that included patients who sustained blunt and penetrating trauma, there was 100% sensitivity and 99% specificity for intraperitoneal bladder rupture; additionally, the specific site of bladder dome injury was found in 4 of the 18 patients and was identified only with multiplanar reconstructed images [14]. An advantage of CT cystography is the ability to diagnose injuries to other pelvic viscera, osseous structures, and vasculature. Contrast-enhanced CT with excretory phase imaging is not a reliable means to diagnose bladder rupture, even after a urethral catheter has been inserted and clamped [2,15,16]. Excretory phase imaging is defined as antegrade filling of the urinary bladder that is due to excretion of intravenous (IV) contrast material through the kidneys. Although intraperitoneal and extraperitoneal fluid can be detected during excretory phase CT, the etiology of the fluid cannot be determined because the bladder is usually inadequately distended to cause extravasation through a bladder laceration or perforation. Although the absence of pelvic fluid is strong evidence against a bladder rupture, a negative study does not exclude bladder injury [17]. The literature suggests that both conventional and CT cystography are equivalent, with physician preference and diagnostic protocols generally defining the method used [2,13,18]. Although CT is not the technique of choice for urethral injuries, it is performed so frequently that urethral injuries are inevitably identified when performed for pelvic trauma. | Penetrating Trauma Lower Abdomen and Pelvis. Since then, CT cystography has become the first-line evaluation for bladder injury in the acute trauma setting [4]. This technique refers to the retrograde instillation of a minimum of 350 cc of diluted contrast media into the bladder, followed by axial and coronal CT images of the pelvis [6,14]. Unlike conventional cystography, no postdrainage CT images are needed. In a study that included patients who sustained blunt and penetrating trauma, there was 100% sensitivity and 99% specificity for intraperitoneal bladder rupture; additionally, the specific site of bladder dome injury was found in 4 of the 18 patients and was identified only with multiplanar reconstructed images [14]. An advantage of CT cystography is the ability to diagnose injuries to other pelvic viscera, osseous structures, and vasculature. Contrast-enhanced CT with excretory phase imaging is not a reliable means to diagnose bladder rupture, even after a urethral catheter has been inserted and clamped [2,15,16]. Excretory phase imaging is defined as antegrade filling of the urinary bladder that is due to excretion of intravenous (IV) contrast material through the kidneys. Although intraperitoneal and extraperitoneal fluid can be detected during excretory phase CT, the etiology of the fluid cannot be determined because the bladder is usually inadequately distended to cause extravasation through a bladder laceration or perforation. Although the absence of pelvic fluid is strong evidence against a bladder rupture, a negative study does not exclude bladder injury [17]. The literature suggests that both conventional and CT cystography are equivalent, with physician preference and diagnostic protocols generally defining the method used [2,13,18]. Although CT is not the technique of choice for urethral injuries, it is performed so frequently that urethral injuries are inevitably identified when performed for pelvic trauma. | 69376 |
acrac_69376_4 | Penetrating Trauma Lower Abdomen and Pelvis | Chou et al [19] described the results of CT voiding urethrography using 16-multidetector CT in 13 men and found a high correlation between the results of conventional RUG and CT voiding urethrography for evaluating traumatic and nontraumatic urethral conditions. Findings of penetrating urethral trauma on CT voiding urethrography include extravasation of contrast media, irregularity of the urethral lumen, and hematomas. CT Pelvis Pelvic CT without IV contrast provides limited evaluation for suspected penetrating injury to the lower urinary tract because of nonopacification of the urinary bladder lumen and lack of enhancement of the pelvic viscera [18]. However, it may be useful in detecting fluid or hematoma adjacent to the urinary bladder, prompting a follow-up evaluation with radiographic or CT cystography. Pelvic CT without IV contrast may be occasionally considered for evaluation of urethral or periurethral foreign body. Pelvic CT with IV contrast allows improved assessment of the pelvic viscera and vessels compared with CT without IV contrast. However, evaluation for bladder injury remains limited because of suboptimal distension and nonopacification of the urinary bladder lumen. The use of antegrade cystography, during which the urinary bladder is gradually opacified by excretion of IV contrast, provides inadequate evaluation of bladder injury that is due to suboptimal distension of the bladder lumen, dilution of excreted contrast material by urine, and the time delay required for excretion of IV contrast [2]. Pelvic CT without and with IV contrast is suboptimal compared with CT cystography because of the reasons described in the previous 2 paragraphs. Specifically, pelvic CT without and with IV contrast does not provide MRI Pelvis There is no relevant literature regarding the use of MRI in the evaluation of penetrating trauma to the lower urinary tract. | Penetrating Trauma Lower Abdomen and Pelvis. Chou et al [19] described the results of CT voiding urethrography using 16-multidetector CT in 13 men and found a high correlation between the results of conventional RUG and CT voiding urethrography for evaluating traumatic and nontraumatic urethral conditions. Findings of penetrating urethral trauma on CT voiding urethrography include extravasation of contrast media, irregularity of the urethral lumen, and hematomas. CT Pelvis Pelvic CT without IV contrast provides limited evaluation for suspected penetrating injury to the lower urinary tract because of nonopacification of the urinary bladder lumen and lack of enhancement of the pelvic viscera [18]. However, it may be useful in detecting fluid or hematoma adjacent to the urinary bladder, prompting a follow-up evaluation with radiographic or CT cystography. Pelvic CT without IV contrast may be occasionally considered for evaluation of urethral or periurethral foreign body. Pelvic CT with IV contrast allows improved assessment of the pelvic viscera and vessels compared with CT without IV contrast. However, evaluation for bladder injury remains limited because of suboptimal distension and nonopacification of the urinary bladder lumen. The use of antegrade cystography, during which the urinary bladder is gradually opacified by excretion of IV contrast, provides inadequate evaluation of bladder injury that is due to suboptimal distension of the bladder lumen, dilution of excreted contrast material by urine, and the time delay required for excretion of IV contrast [2]. Pelvic CT without and with IV contrast is suboptimal compared with CT cystography because of the reasons described in the previous 2 paragraphs. Specifically, pelvic CT without and with IV contrast does not provide MRI Pelvis There is no relevant literature regarding the use of MRI in the evaluation of penetrating trauma to the lower urinary tract. | 69376 |
acrac_69376_5 | Penetrating Trauma Lower Abdomen and Pelvis | MRI plays an ancillary role in the initial imaging evaluation of penetrating lower urinary tract injury that is due to the difficulty of monitoring a seriously injured patient in a strong magnetic field. MRI has been described for follow-up evaluation of urethral injury as an adjunctive tool for assessing complex urethral anatomic derangements [20,21]. Radiography Intravenous Urography There is no recent relevant literature regarding the use of an IV urogram in the evaluation of penetrating trauma to the lower urinary tract. An IV urogram is typically inadequate for evaluating the bladder and urethra after penetrating trauma because the contrast material within the bladder is diluted and the resting intravesical pressure is simply too low to demonstrate a small tear [15]. Fluoroscopy Retrograde Urethrography Patients with penetrating trauma to the penis should undergo RUG as the primary diagnostic procedure because of concern for injury of the anterior urethra [22]. Because posterior urethral injuries can also result from penetrating trauma to the pelvis and perineum, and are associated with pelvic fractures, a RUG should be performed before inserting a catheter [7,10,18]. In the past, a diagnosis of acute urethral injury often was based loosely on the clinical triad of 1) blood at the urethral meatus, 2) inability of the patient to void, and 3) a palpable urinary bladder. An inability to pass the catheter into the bladder was also considered diagnostic of a posterior urethral injury. It is now well established, however, that diagnostic catheterization is to be avoided, as it may convert a partial injury into a complete disruption [2,22]. In female patients with a suprapubic catheter in place, a descending or voiding urethrography may be sufficient; a RUG may also be performed with a small-caliber catheter pressed against, or slightly beyond, the urethral meatus [9]. | Penetrating Trauma Lower Abdomen and Pelvis. MRI plays an ancillary role in the initial imaging evaluation of penetrating lower urinary tract injury that is due to the difficulty of monitoring a seriously injured patient in a strong magnetic field. MRI has been described for follow-up evaluation of urethral injury as an adjunctive tool for assessing complex urethral anatomic derangements [20,21]. Radiography Intravenous Urography There is no recent relevant literature regarding the use of an IV urogram in the evaluation of penetrating trauma to the lower urinary tract. An IV urogram is typically inadequate for evaluating the bladder and urethra after penetrating trauma because the contrast material within the bladder is diluted and the resting intravesical pressure is simply too low to demonstrate a small tear [15]. Fluoroscopy Retrograde Urethrography Patients with penetrating trauma to the penis should undergo RUG as the primary diagnostic procedure because of concern for injury of the anterior urethra [22]. Because posterior urethral injuries can also result from penetrating trauma to the pelvis and perineum, and are associated with pelvic fractures, a RUG should be performed before inserting a catheter [7,10,18]. In the past, a diagnosis of acute urethral injury often was based loosely on the clinical triad of 1) blood at the urethral meatus, 2) inability of the patient to void, and 3) a palpable urinary bladder. An inability to pass the catheter into the bladder was also considered diagnostic of a posterior urethral injury. It is now well established, however, that diagnostic catheterization is to be avoided, as it may convert a partial injury into a complete disruption [2,22]. In female patients with a suprapubic catheter in place, a descending or voiding urethrography may be sufficient; a RUG may also be performed with a small-caliber catheter pressed against, or slightly beyond, the urethral meatus [9]. | 69376 |
acrac_69376_6 | Penetrating Trauma Lower Abdomen and Pelvis | Arteriography There is no relevant literature regarding the use of arteriography in the evaluation of penetrating trauma specific to the lower urinary tract. Arteriography can be useful in identifying an occult source of bleeding and can guide its subsequent therapeutic embolization [15]. Angioembolization has been described as a useful diagnostic and therapeutic tool in trauma patients with pelvic fractures and vascular injuries. US Pelvis Transabdominal ultrasound (US) findings in bladder rupture and urethral evaluation with an endorectal probe have been described in the setting of blunt trauma [15], but US has not been routinely used for evaluating penetrating trauma of the lower urinary tract. Conversely, most or all seriously injured trauma patients will likely be evaluated with CT because of its speed and accuracy of evaluation. US can be used to evaluate associated visceral lesions, such as solid or hollow organ rupture, and nonspecific peritoneal fluid [15]. The detection of peritoneal fluid in the presence of normal viscera or the failure to visualize the bladder after the transurethral introduction of saline are considered highly suggestive of bladder rupture [15]. As a practical matter, US is not definitive in bladder or urethral trauma and is almost never used for this diagnosis. Adequate distention of the urinary bladder is crucial to detecting a perforation, especially in instances of penetrating trauma, as most instances of a false-negative retrograde cystogram were found in this situation [24,25]. To exclude bladder injury, a filling volume of at least 350 to 400 mL of contrast should be achieved. The catheter balloon should not be tightly maintained against the bladder neck because it could tamponade against a disruption and prevent detection of a leak in this region. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch. acr.org/list. | Penetrating Trauma Lower Abdomen and Pelvis. Arteriography There is no relevant literature regarding the use of arteriography in the evaluation of penetrating trauma specific to the lower urinary tract. Arteriography can be useful in identifying an occult source of bleeding and can guide its subsequent therapeutic embolization [15]. Angioembolization has been described as a useful diagnostic and therapeutic tool in trauma patients with pelvic fractures and vascular injuries. US Pelvis Transabdominal ultrasound (US) findings in bladder rupture and urethral evaluation with an endorectal probe have been described in the setting of blunt trauma [15], but US has not been routinely used for evaluating penetrating trauma of the lower urinary tract. Conversely, most or all seriously injured trauma patients will likely be evaluated with CT because of its speed and accuracy of evaluation. US can be used to evaluate associated visceral lesions, such as solid or hollow organ rupture, and nonspecific peritoneal fluid [15]. The detection of peritoneal fluid in the presence of normal viscera or the failure to visualize the bladder after the transurethral introduction of saline are considered highly suggestive of bladder rupture [15]. As a practical matter, US is not definitive in bladder or urethral trauma and is almost never used for this diagnosis. Adequate distention of the urinary bladder is crucial to detecting a perforation, especially in instances of penetrating trauma, as most instances of a false-negative retrograde cystogram were found in this situation [24,25]. To exclude bladder injury, a filling volume of at least 350 to 400 mL of contrast should be achieved. The catheter balloon should not be tightly maintained against the bladder neck because it could tamponade against a disruption and prevent detection of a leak in this region. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch. acr.org/list. | 69376 |
acrac_69417_0 | Suspected Upper Extremity Deep Vein Thrombosis | Introduction/Background Soft-tissue swelling is usually due to an alteration in capillary hemodynamics causing motion of fluid from the vascular spaces into the interstitium, secondary to either increased plasma volume (eg, heart failure, pregnancy), increased capillary hydrostatic pressure (eg, superior vena cava syndrome, deep vein thrombosis [DVT], reflex sympathetic dystrophy, trauma), decreased capillary oncotic pressure (eg, cirrhosis, malnutrition), or increased capillary permeability (eg, allergic reactions, infection, inflammation). It can also be due to lymphatic obstruction (eg, lymphedema, malignancy). The etiology of acute isolated upper-extremity swelling is often apparent from the clinical history (eg, trauma, infection, inflammatory arthritis) or can be suspected when risk factors are present (eg, venous thrombosis due to a venous catheter). Upper-extremity DVT (UEDVT) accounts for up to 10% of all diagnosed DVTs [1,2]. It can be primary in a third of cases due to venous thoracic outlet syndrome [3] (ie, effort-related thrombosis/Paget-Schroetter syndrome) and occasionally is idiopathic. Secondary UEDVT is far more common. Indwelling venous devices, such as catheters, pacemakers, and defibrillators, put patients at the highest risk of thrombus [1,4-10]. Other risk factors include advanced age, previous thrombophlebitis, postoperative state, hypercoagulability [4,11,12], heart failure [4], cancer [7,9-14], right-heart procedures, intensive care unit admissions [1,10], trauma, and extrinsic compression. Patients with certain abnormally elevated coagulation factors were demonstrated to be at increased risk of UEDVT [15]. Although many of the same risk factors for lower-extremity DVT also increase the risk for UEDVT, research is helping to elucidate certain variables unique to thrombi in the upper extremity [1,16]. | Suspected Upper Extremity Deep Vein Thrombosis. Introduction/Background Soft-tissue swelling is usually due to an alteration in capillary hemodynamics causing motion of fluid from the vascular spaces into the interstitium, secondary to either increased plasma volume (eg, heart failure, pregnancy), increased capillary hydrostatic pressure (eg, superior vena cava syndrome, deep vein thrombosis [DVT], reflex sympathetic dystrophy, trauma), decreased capillary oncotic pressure (eg, cirrhosis, malnutrition), or increased capillary permeability (eg, allergic reactions, infection, inflammation). It can also be due to lymphatic obstruction (eg, lymphedema, malignancy). The etiology of acute isolated upper-extremity swelling is often apparent from the clinical history (eg, trauma, infection, inflammatory arthritis) or can be suspected when risk factors are present (eg, venous thrombosis due to a venous catheter). Upper-extremity DVT (UEDVT) accounts for up to 10% of all diagnosed DVTs [1,2]. It can be primary in a third of cases due to venous thoracic outlet syndrome [3] (ie, effort-related thrombosis/Paget-Schroetter syndrome) and occasionally is idiopathic. Secondary UEDVT is far more common. Indwelling venous devices, such as catheters, pacemakers, and defibrillators, put patients at the highest risk of thrombus [1,4-10]. Other risk factors include advanced age, previous thrombophlebitis, postoperative state, hypercoagulability [4,11,12], heart failure [4], cancer [7,9-14], right-heart procedures, intensive care unit admissions [1,10], trauma, and extrinsic compression. Patients with certain abnormally elevated coagulation factors were demonstrated to be at increased risk of UEDVT [15]. Although many of the same risk factors for lower-extremity DVT also increase the risk for UEDVT, research is helping to elucidate certain variables unique to thrombi in the upper extremity [1,16]. | 69417 |
acrac_69417_1 | Suspected Upper Extremity Deep Vein Thrombosis | Patients who develop UEDVT often present with symptoms of ipsilateral upper-extremity edema, pain, paresthesia and, in some instances, functional impairment [16]. Catheter-associated thrombosis may be asymptomatic, rather manifesting as catheter dysfunction or as an incidental finding upon imaging. Superficial thrombophlebitis is associated with local pain, induration, and, often, a palpable cord but is rarely associated with diffuse arm swelling [17]. Unilateral swelling indicates an obstructive process at the level of the brachiocephalic, subclavian, or axillary veins [17,18]. DVT limited to the brachial veins need not be associated with swelling. Isolated jugular vein thrombosis is asymptomatic and rarely causes swelling. There may be a correlation between UEDVT and lower- extremity DVT, and investigation of the lower extremities as well should be considered if an upper-extremity thrombus is found in the absence of a local cause [19]. Diagnosis of UEDVT Venous thrombosis must initially be considered in a patient with upper-extremity swelling because it typically requires anticoagulation and sometimes thrombolysis. Risk stratification can be performed from a combination of clinical features [20] or by using blood tests. Plasma levels of D-dimer, a degradation product of cross-linked fibrin that is elevated during thromboembolic events, is highly sensitive but not very specific [21] and may be useful in ruling out UEDVT in conjunction with low pretest probability [22-24]. However, D-dimer cannot assess the location and extent of DVT, which is critical for proper therapeutic management [25], and is unreliable to distinguish between acute DVT from recurrent DVT. Imaging is often required for definitive exclusion of DVT and to document Reprint requests to: [email protected] Suspected Upper-Extremity Deep Vein Thrombosis its location and extent. Noninvasive imaging is frequently the initial step to assess DVT and includes ultrasound (US), MRI, or CT. | Suspected Upper Extremity Deep Vein Thrombosis. Patients who develop UEDVT often present with symptoms of ipsilateral upper-extremity edema, pain, paresthesia and, in some instances, functional impairment [16]. Catheter-associated thrombosis may be asymptomatic, rather manifesting as catheter dysfunction or as an incidental finding upon imaging. Superficial thrombophlebitis is associated with local pain, induration, and, often, a palpable cord but is rarely associated with diffuse arm swelling [17]. Unilateral swelling indicates an obstructive process at the level of the brachiocephalic, subclavian, or axillary veins [17,18]. DVT limited to the brachial veins need not be associated with swelling. Isolated jugular vein thrombosis is asymptomatic and rarely causes swelling. There may be a correlation between UEDVT and lower- extremity DVT, and investigation of the lower extremities as well should be considered if an upper-extremity thrombus is found in the absence of a local cause [19]. Diagnosis of UEDVT Venous thrombosis must initially be considered in a patient with upper-extremity swelling because it typically requires anticoagulation and sometimes thrombolysis. Risk stratification can be performed from a combination of clinical features [20] or by using blood tests. Plasma levels of D-dimer, a degradation product of cross-linked fibrin that is elevated during thromboembolic events, is highly sensitive but not very specific [21] and may be useful in ruling out UEDVT in conjunction with low pretest probability [22-24]. However, D-dimer cannot assess the location and extent of DVT, which is critical for proper therapeutic management [25], and is unreliable to distinguish between acute DVT from recurrent DVT. Imaging is often required for definitive exclusion of DVT and to document Reprint requests to: [email protected] Suspected Upper-Extremity Deep Vein Thrombosis its location and extent. Noninvasive imaging is frequently the initial step to assess DVT and includes ultrasound (US), MRI, or CT. | 69417 |
acrac_69417_2 | Suspected Upper Extremity Deep Vein Thrombosis | Catheter venography is slightly more invasive but remains the reference standard and offers the potential for initiation of therapy. Other techniques, such as photoplethysmography, lymphoscintigraphy, and fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT have been discussed in the literature as part of the workup for upper-extremity swelling, particularly when lymphedema is a potential cause [26-30]. Discussion of Procedures by Variant Variant 1: Suspected upper-extremity deep vein thrombosis. Initial imaging. US Duplex Doppler Upper Extremity US is a noninvasive test that can be performed at the bedside and used for serial evaluations. US grayscale imaging directly identifies thrombus by visualizing echogenic material in the vein and by lack of compression of the vein walls from manual external pressure by the US probe. Lack of compression is seen for both acute and chronic thrombus [12,31]. Acute hypoechoic thrombi may be missed using grayscale imaging alone. US is most useful in the evaluation of veins peripheral to the subclavian, such as the jugular, axillary, basilic, cephalic, and brachial veins. US can also be used for the evaluation of arteriovenous fistulas in renal patients [40,41]. Compression cannot be used to evaluate more central veins because bony structures prevent visualization or compression of the vessel lumen, but flow in these central veins can be assessed by US [5,12,37]. If only blood flow abnormalities are seen, conventional venography may be necessary [12]. Correlative studies between US and venography show diagnostic sensitivities and specificities above 80% [5,8,12,31,34,35,38,39,42,43]. MRV Upper Extremity MRI uses several techniques to image the veins, with or without intravenous (IV) contrast agents. Noncontrast sequences include bright-blood and black-blood imaging [44] as well as flow-based imaging, such as time-of-flight [45-49] and phase-contrast imaging [47,50]. | Suspected Upper Extremity Deep Vein Thrombosis. Catheter venography is slightly more invasive but remains the reference standard and offers the potential for initiation of therapy. Other techniques, such as photoplethysmography, lymphoscintigraphy, and fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT have been discussed in the literature as part of the workup for upper-extremity swelling, particularly when lymphedema is a potential cause [26-30]. Discussion of Procedures by Variant Variant 1: Suspected upper-extremity deep vein thrombosis. Initial imaging. US Duplex Doppler Upper Extremity US is a noninvasive test that can be performed at the bedside and used for serial evaluations. US grayscale imaging directly identifies thrombus by visualizing echogenic material in the vein and by lack of compression of the vein walls from manual external pressure by the US probe. Lack of compression is seen for both acute and chronic thrombus [12,31]. Acute hypoechoic thrombi may be missed using grayscale imaging alone. US is most useful in the evaluation of veins peripheral to the subclavian, such as the jugular, axillary, basilic, cephalic, and brachial veins. US can also be used for the evaluation of arteriovenous fistulas in renal patients [40,41]. Compression cannot be used to evaluate more central veins because bony structures prevent visualization or compression of the vessel lumen, but flow in these central veins can be assessed by US [5,12,37]. If only blood flow abnormalities are seen, conventional venography may be necessary [12]. Correlative studies between US and venography show diagnostic sensitivities and specificities above 80% [5,8,12,31,34,35,38,39,42,43]. MRV Upper Extremity MRI uses several techniques to image the veins, with or without intravenous (IV) contrast agents. Noncontrast sequences include bright-blood and black-blood imaging [44] as well as flow-based imaging, such as time-of-flight [45-49] and phase-contrast imaging [47,50]. | 69417 |
acrac_69417_3 | Suspected Upper Extremity Deep Vein Thrombosis | Contrast-enhanced MR venography (MRV) techniques are either high resolution or time resolved [47,51]. MRI can image the vessel lumen, the vessel wall, the surrounding structures, and assess for the presence of flow in the vessel. Thrombus can also be imaged directly [52]. Nephrogenic systemic sclerosis has been associated with exposure to some brands of gadolinium-based contrast agents in patients with renal failure [53]. Spin-echo techniques produce black-blood images [33,50] on which thrombus displays high intravascular signal often accompanied by venous enlargement. The high signal decreases after 6 months, and the technique is less useful for chronic thrombus [54]. This imaging technique is not always consistent and is affected by a variety of flow artifacts [50]. Newer double inversion-recovery techniques provide more reliable black-blood imaging [47]. Black-blood imaging is also useful to image the vessel wall, where scan parameters can be adjusted to enhance either T1 or T2 weighting. Balanced gradient-echo techniques produce bright-blood images on which acute thrombus is relatively isointense to blood, making the sequence insensitive to detect acute thrombus [55,56]. The signal of thrombus varies in intensity over time. Cardiac-gated 3-D steady-state free precession and fast spin-echo techniques also produce bright-blood images. Because steady-state free precession images are T1/T2 weighted, visibility of clots depends on the age of thrombus. The weighted subtraction of fast spin-echo images in various phases of the cardiac cycle can help differentiate transient flow artifacts from true filling defects that persist over the cardiac cycle. Both techniques have been implemented for noncontrast MR angiography and appear promising [57-59]. Using time of flight to image veins is usually limited to a 2-D technique. | Suspected Upper Extremity Deep Vein Thrombosis. Contrast-enhanced MR venography (MRV) techniques are either high resolution or time resolved [47,51]. MRI can image the vessel lumen, the vessel wall, the surrounding structures, and assess for the presence of flow in the vessel. Thrombus can also be imaged directly [52]. Nephrogenic systemic sclerosis has been associated with exposure to some brands of gadolinium-based contrast agents in patients with renal failure [53]. Spin-echo techniques produce black-blood images [33,50] on which thrombus displays high intravascular signal often accompanied by venous enlargement. The high signal decreases after 6 months, and the technique is less useful for chronic thrombus [54]. This imaging technique is not always consistent and is affected by a variety of flow artifacts [50]. Newer double inversion-recovery techniques provide more reliable black-blood imaging [47]. Black-blood imaging is also useful to image the vessel wall, where scan parameters can be adjusted to enhance either T1 or T2 weighting. Balanced gradient-echo techniques produce bright-blood images on which acute thrombus is relatively isointense to blood, making the sequence insensitive to detect acute thrombus [55,56]. The signal of thrombus varies in intensity over time. Cardiac-gated 3-D steady-state free precession and fast spin-echo techniques also produce bright-blood images. Because steady-state free precession images are T1/T2 weighted, visibility of clots depends on the age of thrombus. The weighted subtraction of fast spin-echo images in various phases of the cardiac cycle can help differentiate transient flow artifacts from true filling defects that persist over the cardiac cycle. Both techniques have been implemented for noncontrast MR angiography and appear promising [57-59]. Using time of flight to image veins is usually limited to a 2-D technique. | 69417 |
acrac_69417_4 | Suspected Upper Extremity Deep Vein Thrombosis | Rapid flow through the imaging plane produces a bright signal, whereas slow flow or in-plane flow can produce a dark signal due to signal saturation [59]. On axial 2-D time-of-flight images, the jugular veins, right brachiocephalic vein, and superior vena cava are oriented in the superior-inferior direction and produce a bright signal, whereas the left brachiocephalic vein and subclavian 3 Suspected Upper-Extremity Deep Vein Thrombosis veins are oriented in-plane and produce a darker signal, often requiring sagittal 2-D time-of-flight images for best assessment. Breathing artifacts may also impair imaging quality [11,59,60]. Phase-contrast flow imaging has not been widely used for upper-extremity venography because of the slow flows that must be detected [59]. IV gadolinium-based contrast agents [59] can be administered during acquisition of 2-D or 3-D T1-weighted gradient-echo images with fat saturation to produce a very bright signal in patent vessels [45,61,62]. A 90- to 120- second delay is required after injection to allow the contrast bolus to enter the venous or equilibrium phase [47,59] and to generate an MRV. MRV has proven very useful to evaluate the central venous structures, which cannot be directly imaged by US, but US or venography are still preferred to image the more peripheral veins. A few IV contrast agents persist longer in the vessels and have been useful to image the venous structures. Fibrin-specific MR contrast agents can further enhance all thrombi and may even detect thrombi not readily visible in noncontrast imaging [63]. The dynamic filling of vessels by IV contrast agents can be imaged with time-resolved techniques. Such techniques can reduce both IV contrast volume and acquisition time while improving specificity when used as an adjunct to conventional MR sequences [64,65]. | Suspected Upper Extremity Deep Vein Thrombosis. Rapid flow through the imaging plane produces a bright signal, whereas slow flow or in-plane flow can produce a dark signal due to signal saturation [59]. On axial 2-D time-of-flight images, the jugular veins, right brachiocephalic vein, and superior vena cava are oriented in the superior-inferior direction and produce a bright signal, whereas the left brachiocephalic vein and subclavian 3 Suspected Upper-Extremity Deep Vein Thrombosis veins are oriented in-plane and produce a darker signal, often requiring sagittal 2-D time-of-flight images for best assessment. Breathing artifacts may also impair imaging quality [11,59,60]. Phase-contrast flow imaging has not been widely used for upper-extremity venography because of the slow flows that must be detected [59]. IV gadolinium-based contrast agents [59] can be administered during acquisition of 2-D or 3-D T1-weighted gradient-echo images with fat saturation to produce a very bright signal in patent vessels [45,61,62]. A 90- to 120- second delay is required after injection to allow the contrast bolus to enter the venous or equilibrium phase [47,59] and to generate an MRV. MRV has proven very useful to evaluate the central venous structures, which cannot be directly imaged by US, but US or venography are still preferred to image the more peripheral veins. A few IV contrast agents persist longer in the vessels and have been useful to image the venous structures. Fibrin-specific MR contrast agents can further enhance all thrombi and may even detect thrombi not readily visible in noncontrast imaging [63]. The dynamic filling of vessels by IV contrast agents can be imaged with time-resolved techniques. Such techniques can reduce both IV contrast volume and acquisition time while improving specificity when used as an adjunct to conventional MR sequences [64,65]. | 69417 |
acrac_69417_5 | Suspected Upper Extremity Deep Vein Thrombosis | It has found use in protocols for whole-body venography [66] and was shown to produce images of comparable diagnostic quality but lower specificity compared with conventional MRV [67] in the assessment of central thoracic veins. It might eventually be used as a fast, noninvasive, and relatively safe imaging tool for screening and serial follow-up of patients with poor renal function, but further study is required [68]. Standard MRI sequences are always included in MRV protocols because they produce high-resolution images of the soft tissues surrounding the vessels and can help identify mimics of DVT and potential sources of extrinsic venous compression as well as signs of soft-tissue inflammation around the veins (edema on T2-weighted images and contrast enhancement on postcontrast T1-weighted sequences). MRV can be as effective as venography [46,62] but has limitations [33,45,50]. A meta-analysis found MRV to have both a high sensitivity and specificity [69], although the study did not focus on the upper extremities. CTV Upper Extremity CT can be used to assess the lumen of venous structures. It involves the injection of an iodinated contrast agent [34,38]. Delayed imaging at 90 to 120 seconds can permit evaluation of the central veins. CT can detect thrombi in vascular lumen or stenosis of the lumen. It has been used to assess the jugular veins [70,71], the brachiocephalic veins [72,73], and the superior vena cava [72]. Perivascular inflammatory changes around acute thrombi can also be detected by CT [74]. CT can be used to visualize external processes causing vascular compression or invasion, such as neoplastic processes [75]. CT is the main imaging modality for staging neoplastic involvement in the mediastinum and axillae, which can include vascular invasion or compression. | Suspected Upper Extremity Deep Vein Thrombosis. It has found use in protocols for whole-body venography [66] and was shown to produce images of comparable diagnostic quality but lower specificity compared with conventional MRV [67] in the assessment of central thoracic veins. It might eventually be used as a fast, noninvasive, and relatively safe imaging tool for screening and serial follow-up of patients with poor renal function, but further study is required [68]. Standard MRI sequences are always included in MRV protocols because they produce high-resolution images of the soft tissues surrounding the vessels and can help identify mimics of DVT and potential sources of extrinsic venous compression as well as signs of soft-tissue inflammation around the veins (edema on T2-weighted images and contrast enhancement on postcontrast T1-weighted sequences). MRV can be as effective as venography [46,62] but has limitations [33,45,50]. A meta-analysis found MRV to have both a high sensitivity and specificity [69], although the study did not focus on the upper extremities. CTV Upper Extremity CT can be used to assess the lumen of venous structures. It involves the injection of an iodinated contrast agent [34,38]. Delayed imaging at 90 to 120 seconds can permit evaluation of the central veins. CT can detect thrombi in vascular lumen or stenosis of the lumen. It has been used to assess the jugular veins [70,71], the brachiocephalic veins [72,73], and the superior vena cava [72]. Perivascular inflammatory changes around acute thrombi can also be detected by CT [74]. CT can be used to visualize external processes causing vascular compression or invasion, such as neoplastic processes [75]. CT is the main imaging modality for staging neoplastic involvement in the mediastinum and axillae, which can include vascular invasion or compression. | 69417 |
acrac_69417_6 | Suspected Upper Extremity Deep Vein Thrombosis | No large series of studies have looked at the diagnostic accuracy of this technique for diagnosing upper-extremity venous thrombosis, although extensive experience is accumulating with lower-extremity venous thrombosis. One small series showed that the performance of CT venography (CTV) is similar to that of conventional venography in the thoracic and upper- extremity veins and it evaluates the central extent of obstruction more effectively [75]. Nuclear Medicine Venography Upper Extremity Radionuclide venography involves the peripheral injection of radiopharmaceuticals or labeled small particles (eg, macroaggregated albumin, red blood cells, albumin, platelets) to assess drainage of extremities via the veins or lymphatics, or to directly detect the presence of thrombus (eg, platelets or specific markers). Patent vessels will take up the radiopharmaceuticals, whereas obstructed vessels will not. Failure to visualize specific veins, combined with 4 Suspected Upper-Extremity Deep Vein Thrombosis visualization of collateral veins, indicate either venous thrombosis or external compression of venous segments [2,25,26,28]. Radionuclide venography has been considered the reference standard for lymphedema [77]. For edema related to lymphatic obstruction, the presence of certain features, such as dermal backflow and lymph node asymmetry, can increase the diagnostic specificity after intradermal injection [78]. Some authors have indicated that differentiating between primary lymphedema and secondary lymphedema, such as that due to venous obstruction, may be limited when using intradermal lymphangiography alone [79]. MR lymphangiography is currently being evaluated as an alternative to conventional, radionuclide lymphoscintigraphy and may play a larger role in the future [80,81]. Radiography Chest Although chest radiography cannot assess vascular patency, it can identify factors that can cause external compression or invasion of vessels, such as cervical rib or a mass lesion. | Suspected Upper Extremity Deep Vein Thrombosis. No large series of studies have looked at the diagnostic accuracy of this technique for diagnosing upper-extremity venous thrombosis, although extensive experience is accumulating with lower-extremity venous thrombosis. One small series showed that the performance of CT venography (CTV) is similar to that of conventional venography in the thoracic and upper- extremity veins and it evaluates the central extent of obstruction more effectively [75]. Nuclear Medicine Venography Upper Extremity Radionuclide venography involves the peripheral injection of radiopharmaceuticals or labeled small particles (eg, macroaggregated albumin, red blood cells, albumin, platelets) to assess drainage of extremities via the veins or lymphatics, or to directly detect the presence of thrombus (eg, platelets or specific markers). Patent vessels will take up the radiopharmaceuticals, whereas obstructed vessels will not. Failure to visualize specific veins, combined with 4 Suspected Upper-Extremity Deep Vein Thrombosis visualization of collateral veins, indicate either venous thrombosis or external compression of venous segments [2,25,26,28]. Radionuclide venography has been considered the reference standard for lymphedema [77]. For edema related to lymphatic obstruction, the presence of certain features, such as dermal backflow and lymph node asymmetry, can increase the diagnostic specificity after intradermal injection [78]. Some authors have indicated that differentiating between primary lymphedema and secondary lymphedema, such as that due to venous obstruction, may be limited when using intradermal lymphangiography alone [79]. MR lymphangiography is currently being evaluated as an alternative to conventional, radionuclide lymphoscintigraphy and may play a larger role in the future [80,81]. Radiography Chest Although chest radiography cannot assess vascular patency, it can identify factors that can cause external compression or invasion of vessels, such as cervical rib or a mass lesion. | 69417 |
acrac_3102403_0 | Placenta Accreta Spectrum Disorder | Introduction/Background Placenta accreta spectrum disorder (PASD) is the current terminology recommended by the International Federation of Obstetrics and Gynecology (FIGO) and should replace terms such as abnormally adherent/invasive placenta or morbidly adherent placenta [1]. PASD refers to a variety of potential clinical complications, which may result from abnormal placental implantation. More specifically, placenta accreta refers to a defect in the decidua basalis in which the chorionic villi adhere directly to the myometrium with trophoblastic invasion. More invasive placentation includes placental increta, in which placental villi invade into the myometrium, and placenta percreta, in which the placenta villi invade through the myometrium and into the serosa and adjacent structures [2]. A single placenta can demonstrate varying degrees of invasiveness, and a decidual defect may be accompanied by focal loss of myometrium, often related to prior surgery or trauma. The pathology and underlying mechanism for placenta accreta is not well understood but is thought to be related to a defect in trophoblastic function versus a failure of normal decidualization or a combination of both [1,3,4]. The risk of severe and even life-threatening hemorrhage is greatest at the time of delivery when a portion of the placenta does not separate in the usual fashion. Accurate antenatal diagnosis is needed to plan for an appropriate delivery strategy at an experienced center in order to reduce maternal morbidity [11]. Management of delivery is variable; however, the American Congress of Obstetricians and Gynecologists (ACOG) and FIGO recommend planned cesarean delivery with or without hysterectomy depending on the suspected severity of PASD around 34 to 38 weeks. There is currently insufficient evidence to determine the exact optimal time of delivery. | Placenta Accreta Spectrum Disorder. Introduction/Background Placenta accreta spectrum disorder (PASD) is the current terminology recommended by the International Federation of Obstetrics and Gynecology (FIGO) and should replace terms such as abnormally adherent/invasive placenta or morbidly adherent placenta [1]. PASD refers to a variety of potential clinical complications, which may result from abnormal placental implantation. More specifically, placenta accreta refers to a defect in the decidua basalis in which the chorionic villi adhere directly to the myometrium with trophoblastic invasion. More invasive placentation includes placental increta, in which placental villi invade into the myometrium, and placenta percreta, in which the placenta villi invade through the myometrium and into the serosa and adjacent structures [2]. A single placenta can demonstrate varying degrees of invasiveness, and a decidual defect may be accompanied by focal loss of myometrium, often related to prior surgery or trauma. The pathology and underlying mechanism for placenta accreta is not well understood but is thought to be related to a defect in trophoblastic function versus a failure of normal decidualization or a combination of both [1,3,4]. The risk of severe and even life-threatening hemorrhage is greatest at the time of delivery when a portion of the placenta does not separate in the usual fashion. Accurate antenatal diagnosis is needed to plan for an appropriate delivery strategy at an experienced center in order to reduce maternal morbidity [11]. Management of delivery is variable; however, the American Congress of Obstetricians and Gynecologists (ACOG) and FIGO recommend planned cesarean delivery with or without hysterectomy depending on the suspected severity of PASD around 34 to 38 weeks. There is currently insufficient evidence to determine the exact optimal time of delivery. | 3102403 |
acrac_3102403_1 | Placenta Accreta Spectrum Disorder | The timing of the delivery is planned carefully on a case-by-case basis at around 34 to 38 weeks to achieve optimal fetal maturity and avoid the chance of spontaneous labor. Given that the majority of PASD are associated with placenta previa, they are at increased risk of prepartum hemorrhage as gestational age increases, which in turn is associated with increased risk of unscheduled delivery [11,12]. Although a planned delivery is preferred, a contingency plan for emergent delivery should be in place [4]. Obtaining radiologic and clinical data when PASD The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Placenta Accreta Spectrum Disorder is first suspected can play a significant role in formulating an appropriate delivery strategy and contingency plan. Ideally after initial diagnosis, high-risk patients should be followed closely by experienced centers where emergent mobilization of a multidisciplinary team needed for a scheduled or unscheduled delivery is feasible [13]. Discussion of Procedures by Variant Variant 1: Low risk for placenta accreta spectrum disorder. No known clinical risk factors. Initial imaging. Women who do not have any clinical risk factors and no evidence of previa during an 18- to 22-week anatomy scan can be followed per ACOG clinical guidelines [4]. MRI Abdomen and Pelvis (Without and With IV Contrast) There is no relevant literature to support the use of MRI without or with intravenous (IV) contrast in the initial imaging evaluation for low-risk pregnancy unless concerning findings are present on routine ultrasound (US) [13]. | Placenta Accreta Spectrum Disorder. The timing of the delivery is planned carefully on a case-by-case basis at around 34 to 38 weeks to achieve optimal fetal maturity and avoid the chance of spontaneous labor. Given that the majority of PASD are associated with placenta previa, they are at increased risk of prepartum hemorrhage as gestational age increases, which in turn is associated with increased risk of unscheduled delivery [11,12]. Although a planned delivery is preferred, a contingency plan for emergent delivery should be in place [4]. Obtaining radiologic and clinical data when PASD The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Placenta Accreta Spectrum Disorder is first suspected can play a significant role in formulating an appropriate delivery strategy and contingency plan. Ideally after initial diagnosis, high-risk patients should be followed closely by experienced centers where emergent mobilization of a multidisciplinary team needed for a scheduled or unscheduled delivery is feasible [13]. Discussion of Procedures by Variant Variant 1: Low risk for placenta accreta spectrum disorder. No known clinical risk factors. Initial imaging. Women who do not have any clinical risk factors and no evidence of previa during an 18- to 22-week anatomy scan can be followed per ACOG clinical guidelines [4]. MRI Abdomen and Pelvis (Without and With IV Contrast) There is no relevant literature to support the use of MRI without or with intravenous (IV) contrast in the initial imaging evaluation for low-risk pregnancy unless concerning findings are present on routine ultrasound (US) [13]. | 3102403 |
acrac_3102403_2 | Placenta Accreta Spectrum Disorder | MRI Abdomen and Pelvis (Without IV Contrast) There is no relevant literature to support the use of MRI without IV contrast in the initial imaging evaluation for low-risk pregnancy unless concerning findings are present on routine US [13]. US Duplex Doppler Pregnant Uterus Doppler evaluation should be considered if any abnormalities of placental tissue or in the placental myometrial interface are detected on grayscale imaging regardless of placental location [4,14]. US Pregnant Uterus Transabdominal Routine transabdominal US evaluation of placental location, appearance, and its relationship to internal os is done as documented in the ACR-ACOG-AIUM-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetrical Ultrasound [15]. US Pregnant Uterus Transvaginal Transvaginal (or transperineal) US views may be helpful in visualizing the internal cervical os and its relationship to the placenta if not clear on transabdominal US [15]. Variant 2: High risk for placenta accreta spectrum disorder. Initial Imaging. The main risk factors for PASD include prior uterine surgery, including myomectomy, dilatation, and curettage, most notably cesarean delivery with concomitant anterior placenta previa, followed by advanced maternal age and in vitro fertilization. As many as 40% of women with placenta previa and three prior cesarean deliveries will develop PASD [8-10]. Women with high risk based on clinical history and/or US findings should be considered for referral for specialist imaging to confirm or exclude this diagnosis. Numerous studies have evaluated the use of US for the diagnosis of placenta accreta. US sensitivities have been reported to range from 77% to 97% with specificities of 96% to 98%, positive predictive value of 65% to 93%, and negative predictive value of 98% for PASD [16-21]. A meta-analysis of over 3,500 patients showed US to have high accuracy for diagnosing abnormal placentation, which improved with the addition of color Doppler [3]. | Placenta Accreta Spectrum Disorder. MRI Abdomen and Pelvis (Without IV Contrast) There is no relevant literature to support the use of MRI without IV contrast in the initial imaging evaluation for low-risk pregnancy unless concerning findings are present on routine US [13]. US Duplex Doppler Pregnant Uterus Doppler evaluation should be considered if any abnormalities of placental tissue or in the placental myometrial interface are detected on grayscale imaging regardless of placental location [4,14]. US Pregnant Uterus Transabdominal Routine transabdominal US evaluation of placental location, appearance, and its relationship to internal os is done as documented in the ACR-ACOG-AIUM-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetrical Ultrasound [15]. US Pregnant Uterus Transvaginal Transvaginal (or transperineal) US views may be helpful in visualizing the internal cervical os and its relationship to the placenta if not clear on transabdominal US [15]. Variant 2: High risk for placenta accreta spectrum disorder. Initial Imaging. The main risk factors for PASD include prior uterine surgery, including myomectomy, dilatation, and curettage, most notably cesarean delivery with concomitant anterior placenta previa, followed by advanced maternal age and in vitro fertilization. As many as 40% of women with placenta previa and three prior cesarean deliveries will develop PASD [8-10]. Women with high risk based on clinical history and/or US findings should be considered for referral for specialist imaging to confirm or exclude this diagnosis. Numerous studies have evaluated the use of US for the diagnosis of placenta accreta. US sensitivities have been reported to range from 77% to 97% with specificities of 96% to 98%, positive predictive value of 65% to 93%, and negative predictive value of 98% for PASD [16-21]. A meta-analysis of over 3,500 patients showed US to have high accuracy for diagnosing abnormal placentation, which improved with the addition of color Doppler [3]. | 3102403 |
acrac_3102403_3 | Placenta Accreta Spectrum Disorder | These results are mainly applicable for the anterior placenta (either low lying or previa) in patients with previous cesarean delivery [3]. As per the recently updated SMFM-ACOG-SGO consensus document, US evaluation is important, but the absence of US findings does not preclude a diagnosis of PASD [13]. In patients with known history of prior cesarean delivery and/or low placenta or placenta previa, special attention should be paid on first trimester or nuchal translucency scanning to determine if there is a low implantation or cesarean section scar pregnancy that has been associated with increased risk for PASD [6,10,22-25]. MRI Abdomen and Pelvis (Without and With IV Contrast) There is insufficient evidence to support the use of gadolinium based contrast agents in MRI for this indication because there is no literature clearly establishing improved delineation of placenta and myometrium and the use of gadolinium based contrast agents remains controversial in pregnancy [26,27]. One series using gadolinium contrast compared imaging findings to pathology and reported good accuracy of US, with sensitivity for placenta accreta of 77%, specificity of 96%, but improved accuracy with MRI with corresponding sensitivity of 88% and specificity of 100% [20]. Gadolinium-based contrast agents are considered category C drugs, and their use should be considered only if the benefits outweigh the risks to the fetus. For example, IV contrast may be considered as an exception immediately prior to delivery or, in rare cases, in circumstances in which termination is planned [14]. Placenta Accreta Spectrum Disorder MRI Abdomen and Pelvis (Without IV Contrast) MRI without IV contrast may play a complementary or selective role in situations in which US is equivocally nondiagnostic, severely abnormal in the setting of posterior placentation, or limited by obesity that limits US assessment [14,20,28-34]. | Placenta Accreta Spectrum Disorder. These results are mainly applicable for the anterior placenta (either low lying or previa) in patients with previous cesarean delivery [3]. As per the recently updated SMFM-ACOG-SGO consensus document, US evaluation is important, but the absence of US findings does not preclude a diagnosis of PASD [13]. In patients with known history of prior cesarean delivery and/or low placenta or placenta previa, special attention should be paid on first trimester or nuchal translucency scanning to determine if there is a low implantation or cesarean section scar pregnancy that has been associated with increased risk for PASD [6,10,22-25]. MRI Abdomen and Pelvis (Without and With IV Contrast) There is insufficient evidence to support the use of gadolinium based contrast agents in MRI for this indication because there is no literature clearly establishing improved delineation of placenta and myometrium and the use of gadolinium based contrast agents remains controversial in pregnancy [26,27]. One series using gadolinium contrast compared imaging findings to pathology and reported good accuracy of US, with sensitivity for placenta accreta of 77%, specificity of 96%, but improved accuracy with MRI with corresponding sensitivity of 88% and specificity of 100% [20]. Gadolinium-based contrast agents are considered category C drugs, and their use should be considered only if the benefits outweigh the risks to the fetus. For example, IV contrast may be considered as an exception immediately prior to delivery or, in rare cases, in circumstances in which termination is planned [14]. Placenta Accreta Spectrum Disorder MRI Abdomen and Pelvis (Without IV Contrast) MRI without IV contrast may play a complementary or selective role in situations in which US is equivocally nondiagnostic, severely abnormal in the setting of posterior placentation, or limited by obesity that limits US assessment [14,20,28-34]. | 3102403 |
acrac_3102403_4 | Placenta Accreta Spectrum Disorder | MRI may be used to assist with surgical planning, such as choosing between hysterectomy and a more conservative surgery. The knowledge of the precise topography, including depth or laterality of invasion based on the MRI findings, can alter the surgical approach with regard to a need for ureteral stenting, vascular clamping, and/or embolization [3,35]. It has been suggested that MRI is particularly valuable in detecting placental invasion to parametrium [11]. Because MRI is also associated with both false-positive and false-negative diagnoses [36], the examination may be complementary to the US evaluation. The earliest recommended timing for a diagnostic quality MRI scan after a suspicious US is after 24 weeks [32]. An earlier MRI may be useful in a limited setting, such as preoperative planning for termination of the pregnancy or in the setting of severe disease for staging. Interobserver agreement has been shown to improve with extent of placental invasion [28]. At least four studies have performed direct comparison of MRI with US and found sensitivity of 93% and specificity of 94% for MRI compared with 88% and 96%, respectively, for US [37-40]. Warshak et al [20] advised a 2-stage protocol, starting with US and followed by MRI. Pregnant patients can be informed that there are no known deleterious effects on the fetus performed in 1.5T or 3.0T magnets [41]. US Duplex Doppler Pregnant Uterus The addition of Doppler imaging can improve both detection and progression of the presence of increased placental vascular flow, subplacental vascularity, and vascularity at the bladder uterine-serosal interface, with vessels seen crossing or bridging from placenta to bladder. The presence of multiple vascular lacunae in the placenta is thought to be related to the exposure to pulsatile blood flow, high-velocity blood flow from myometrium to lacunae. | Placenta Accreta Spectrum Disorder. MRI may be used to assist with surgical planning, such as choosing between hysterectomy and a more conservative surgery. The knowledge of the precise topography, including depth or laterality of invasion based on the MRI findings, can alter the surgical approach with regard to a need for ureteral stenting, vascular clamping, and/or embolization [3,35]. It has been suggested that MRI is particularly valuable in detecting placental invasion to parametrium [11]. Because MRI is also associated with both false-positive and false-negative diagnoses [36], the examination may be complementary to the US evaluation. The earliest recommended timing for a diagnostic quality MRI scan after a suspicious US is after 24 weeks [32]. An earlier MRI may be useful in a limited setting, such as preoperative planning for termination of the pregnancy or in the setting of severe disease for staging. Interobserver agreement has been shown to improve with extent of placental invasion [28]. At least four studies have performed direct comparison of MRI with US and found sensitivity of 93% and specificity of 94% for MRI compared with 88% and 96%, respectively, for US [37-40]. Warshak et al [20] advised a 2-stage protocol, starting with US and followed by MRI. Pregnant patients can be informed that there are no known deleterious effects on the fetus performed in 1.5T or 3.0T magnets [41]. US Duplex Doppler Pregnant Uterus The addition of Doppler imaging can improve both detection and progression of the presence of increased placental vascular flow, subplacental vascularity, and vascularity at the bladder uterine-serosal interface, with vessels seen crossing or bridging from placenta to bladder. The presence of multiple vascular lacunae in the placenta is thought to be related to the exposure to pulsatile blood flow, high-velocity blood flow from myometrium to lacunae. | 3102403 |
acrac_3102403_5 | Placenta Accreta Spectrum Disorder | The presence of placental lacunae in the second trimester scan has been shown to have the highest sensitivity and positive predictive value for placenta accreta [37]. Comstock et al [37] observed lacunae in a majority of placenta accreta patients in second trimester scans. When lacunae are multiple, large, and irregular, they are highly suggestive of placenta accreta, but placenta accreta can occur in their absence. On grayscale transabdominal US, the imaging findings that suggest placenta accreta include the presence of intraplacental lacunae (sonolucent spaces that can have slow-moving to more suspicious turbulent moving flow, Placenta Accreta Spectrum Disorder also called intraplacental lakes), loss of the normal hypoechoic retroplacental zone or clear space, reduced myometrial thickness of <1 cm, placental bulging (ballooning of the uterus containing placenta from its expected plane into surrounding tissue, usually into the urinary bladder), and the presence of bladder wall abnormalities. Interruption, thickening, or irregularity of the uterine serosa-bladder line interface has been reported to have high sensitivity and specificity for accreta, more striking as the depth of invasion progresses [2]. Sensitivity of US has been reported to range from 77% to 93%, with positive predictive value of 65% to 93%, and prevalence of 9% to 44% [6,16,37,38,46]. As an isolated finding, loss of the normal retroplacental zone has a reported sensitivity of only 52% and specificity of 57%, with a high false-positive rate of 21% because the normal retroplacental zone may also be absent in normal anterior placentas as well [2,46-48]. Another limitation in the assessment for placental invasion is when the placenta is not low lying. Recognition of a history of prior surgery in these cases may be helpful, as well as meticulous attention to placental morphology and structure. | Placenta Accreta Spectrum Disorder. The presence of placental lacunae in the second trimester scan has been shown to have the highest sensitivity and positive predictive value for placenta accreta [37]. Comstock et al [37] observed lacunae in a majority of placenta accreta patients in second trimester scans. When lacunae are multiple, large, and irregular, they are highly suggestive of placenta accreta, but placenta accreta can occur in their absence. On grayscale transabdominal US, the imaging findings that suggest placenta accreta include the presence of intraplacental lacunae (sonolucent spaces that can have slow-moving to more suspicious turbulent moving flow, Placenta Accreta Spectrum Disorder also called intraplacental lakes), loss of the normal hypoechoic retroplacental zone or clear space, reduced myometrial thickness of <1 cm, placental bulging (ballooning of the uterus containing placenta from its expected plane into surrounding tissue, usually into the urinary bladder), and the presence of bladder wall abnormalities. Interruption, thickening, or irregularity of the uterine serosa-bladder line interface has been reported to have high sensitivity and specificity for accreta, more striking as the depth of invasion progresses [2]. Sensitivity of US has been reported to range from 77% to 93%, with positive predictive value of 65% to 93%, and prevalence of 9% to 44% [6,16,37,38,46]. As an isolated finding, loss of the normal retroplacental zone has a reported sensitivity of only 52% and specificity of 57%, with a high false-positive rate of 21% because the normal retroplacental zone may also be absent in normal anterior placentas as well [2,46-48]. Another limitation in the assessment for placental invasion is when the placenta is not low lying. Recognition of a history of prior surgery in these cases may be helpful, as well as meticulous attention to placental morphology and structure. | 3102403 |
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