string: 5175 Int J Clin Exp Pathol 2014;7(8):5171-5176 mainly supplied by the short circumflex brunch of pontine arteries, and they are from the basilar artery with a right angle or obtuse angle, which are small, the upper part of pons is more susceptible to ischemia than the lower part, so III-V IPL prolonged over I-III [14], and III-V/I-III>1.