Experimental acute renal artery stenosis. Dynamic CT and renal perfusion

Unilateral renal artery stenosis of varying degrees was induced in six of seven pigs. Renal perfusion prior to and after stenosing the renal artery was determined by standard renal clearance and by the direct measurement of renal blood flow. Renal blood flow was reduced from 29 to 56% (mean 40%) in the poststenotic ischemic kidneys. A significant correlation was found between the opacification of the poststenotic ischemic kidneys after intraaortic bolus injection and direct renal blood flow (r = 0.89, P less than 0.01). There was also a significant correlation (r = 0.85, P less than 0.01) between the opacification of the kidneys and their respective glomerular filtration rates. Renal opacification determined by CT correlates significantly with renal perfusion.