Renal parenchymal abnormalities associated with renal vein thrombosis: correlation between MR imaging and pathologic findings in rabbits

The purpose of this study was to correlate abnormalities of the renal parenchyma seen on MR images with pathologic findings in rabbits with acute thrombosis of the renal vein.MR images were obtained in 21 rabbits before and 1 hr to 2 weeks after ligation of the renal vein. MR findings were correlated with pathologic findings.The cross-sectional area of the kidney was 1.7, 1.8, 1.9, 2.2, 1.3, and 1.0 times of its initial size at 1 hr, 3 hr, 1 day, 3 days, 1 week, and 2 weeks, respectively, after ligation of the renal vein. Corticomedullary contrast on T1-weighted images decreased persistently from 1 hr to 2 weeks after ligation. Between 1 hr and 1 week after ligation, T2-weighted images showed a layer with low signal intensity that was correlated with medullary congestion and hemorrhage on pathologic specimens.MR images show a layer with low signal intensity in the renal medulla that probably represents medullary congestion and hemorrhage of the kidney in rabbits with acute thrombosis of the renal vein.