Radiology Most important sign in hemodynamically significant renal artery stenosis A Presence of collateral vessels B Elevated renin level in I/L renal vein ≥ 1.5 : 1 C Transstenotic pressure gradient ≥ 40 mm Hg D Decrease in renal size 💡 Explanation Most important sign in hemodynamically significant renal artery stenosis ✓ Correct Answer: A. Presence of collateral vessels