The accuracy and limitations of ultrasound in the assessment of venous extension in renal carcinoma.

Ultrasound was used to assess venous extension in 28 patients with renal carcinoma, with particular reference to involvement of the inferior vena cava. The findings were correlated with surgical findings in all except two patients who had gross caval involvement and metastatic disease and in whom surgery was considered inappropriate. In 10 of the 28 patients (36%), a diagnostic ultrasound examination of the cava from the renal veins to the diaphragm was obtained. In four of these, ultrasound showed tumour involvement of the vena cava. In 12 cases (43%) only the intrahepatic part of the cava was seen, but the examination nonetheless excluded tumour involvement of the upper cava. Visualisation of the vena cava was impossible in six cases (21%), usually because of bowel gas or obesity; CT scanning provided valuable additional information in two of these cases. Inferior vena cavography confirmed the findings of the less invasive imaging procedures in 10 patients and was falsely positive once. Cavography is now seldom necessary in the assessment of renal carcinoma.