Radiology General f509f5d9 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 High-Yield Explanation All are signs of renal artery stenosis. Most important - Presence of collateral vessels.