COMPUTED TOMOGRARHIC EVALUATION OF THE RENAL VEIN IN THE NORMAL AND TUMOR KIDNEYS

Abstract

In 37 normal kidneys and 23 kidneys with renal cell carcinoma, in all of which computed tomography (CT) was taken at our department of the Jikei University Hospital during the 2 years' period from Nov. 1978 to Oct. 1980, the renal vein as revealed by CT was studied. CT scanning was made with Somatom, with scanning time of 4.5sec, the matrix of 256×256, and section thickness of 7 or 8mm. As a rule, the scanning covered the region from the ensiform process to the iliac crest at intervals of 1cm.
The renal vein could be depicted by this method in 89 and 87% of the normal and tumor kidneys, respectively. There was a tendency that the right renal vein was depicted with lower incidence than the left. The best picture of the renal vein was obtained with scanning in the area at 7 and 8cm level below the ensiform process for both normal and tumor kidneys.
The diameter of the normal renal vein was less than 1.0cm in 89% of the cases, with no case exceeding 1.4cm. Therefore, in cases where there was an extention of the renal vein with a diameter larger than 1.4cm, tumor thrombus in the renal vein or renal arterio-venous fistula should be considered. In fact, among 5 cases where an extended renal vein was observed, a tumor thrombus was detected in the renal vein in 4 cases and a renal arterio-venous fistula in one case.
When CT is performed in renal disease, especially for diagnosis of renal tumor, it is important to pay attention to diseases not only in the kidney but in the renal vein also.