Radiology – MCQ 21 – Angiographic sign of renal artery stenosis

The most important sign of signficant renal artery stenosis in an angiogram is:
A. A percentage diameter stenosis > 70%
B. Presence of collaterals
C. A systolic pressure gradient > 20 mm Hg across the lesion
D. Poststenotic dilatation of the renal artery

Correct answer : B. Presence of collaterals

Presence of collaterals indicate that there is significant renal artery stenosis.