Figure 16a. Renal artery stenosis in a hypertensive patient imaged with CT angiography (1.0-mm section thickness). (a) Coronal shaded-surface display image shows a patent aortobiiliac bypass graft (arrows) and a right iliac to left renal artery bypass graft (arrowhead). (b) A 20° oblique maximum-intensity projection image shows severe renal artery stenosis (arrow), which was missed on a preoperative conventional arteriogram.