Impact of magnetic resonance on staging of renal carcinoma.

Computerized tomography (CT), ultrasound, and angiography have been used for staging renal cell carcinoma. CT has proven to be the most reliable and sensitive of these techniques. Magnetic resonance (MR) has emerged recently as a viable alternative imaging modality. Five patients with renal cell carcinoma and suspected caval involvement were evaluated by CT, ultrasound, and MR. Caval extension and the differentiation of intra-versus retrocaval tumor was seen with greater clarity on MR scans; perinephric extension was seen equally well with both modalities. The primary tumor itself was better defined with CT. In patients with equivocal findings regarding the renal veins or inferior vena cava, MR is a valuable adjunct in preoperative evaluation. In patients at high risk for contrast administration, MR is the staging modality of choice.