IVP is seldom utilized for the diagnosis. Occasionally, inferior vena cavography is not diagnostic, at which point selective renal vein catheterization can be performed. See Figure 3. Inferior vena cavogram of renal venous thrombosis. Renal arteriography may be useful in situations where RVT is secondary to trauma or tumor, in which case renal artery involvement is common.
Renal ultrasound is a safe, noninvasive technique.
With underlying RVT, the kidneys swell and become echogenic, with prominent echo poor medullary pyramids. Color Doppler scanning may also provide information. However, ultrasound is usually not sensitive enough for diagnosis. Intravenous infusion of contrast material assists in visualizing the renal veins. MRI produces high contrast images between flowing blood, vascular walls and surrounding tissue.