Update app.py

app.py

@@ -110,6 +110,7 @@ def predict_brain_age(nifti_file, actual_age, sex):
         predicted_brain_age + (actual_age * 0.062) - 2.96 if actual_age > 18 else predicted_brain_age
     )
 
+    brain_age_difference = predicted_brain_age - actual_age
     # Determine color: Red if positive, Green if negative
     color = "red" if brain_age_difference > 0 else "green"
     bad_output_html = f"<span style='color:{color}; font-weight:bold;'>Brain Age Difference (BAD): {brain_age_difference:.2f} years</span>"
@@ -123,7 +124,7 @@ with gr.Blocks() as demo:
     # 🧠 BrainAgeNeXt: Advancing Brain Age Modeling
     Upload a preprocessed T1w MRI scan (.nii.gz), enter the age and sex of the subject, and get a brain age prediction.
 
-    The following preprocessing are required.
+    The following preprocessing steps are required.
     1. Skull-stripping using [SynthStrip](https://surfer.nmr.mgh.harvard.edu/docs/synthstrip/) with the `--no-csf` flag for optimal results.
     2. N4 bias field correction using [ANTs](https://github.com/ANTsX/ANTs/wiki/N4BiasFieldCorrection).
     3. Affine registration to the MNI 1mm isotropic template space.