Sonographic manifestations of acute renal vein thrombosis: an experimental study.

Complete unilateral ligation of the renal vein was done in five adult mongrel dogs. An initial ultrasound examination was performed at 6 hours with serial scans every 12 hours until the animals died or were sacrificed. There were a number of sonographic findings, consisting of immediate renal enlargement, increased cortical thickness, sparsely distributed cortical echoes with increased transonance, indistinct cortico-medullary boundary, parenchymal anechoic areas due to hemorrhage and hemorrhagic infarct, compressed renal parenchyma appearing as echogenic clusters, dilated renal veins, and renal rupture. These findings corresponded to changes in the pathologic specimens and were dependent upon the duration of the venous occlusion. In patients clinically suspected to have renal vein thrombosis, the combination of the above-described sonographic findings supplemented with findings on excretory urography should be sufficient for the diagnosis of renal vein thrombosis, eliminating the need for invasive procedures.