Contrast studies of the inferior vena cava represent one diagnostic modality employed in the more detailed evaluation of the retroperitoneal space. It was known from previous personal observations that hepatic enlargement could result in an encroachment upon the subdiaphragmatic portion of the inferior vena cava.3 Furthermore, enlarged retroperitoneal lymph nodes were occasionally observed to compress the posterior aspect of the vein. In view of the anatomic relationship of the inferior vena cava to the various retroperitoneal structures (Fig. 1) it could be anticipated that masses involving the area of the head of the pancreas or of the porta hepatis could eventually alter the anterior contour of the inferior vena cava. Up to the present, this postulation has proved to be correct where inoperable carcinoma of the head of the pancreas and marked enlargement of the common duct and retropancreaticoduodenal lymph nodes are concerned.
Inferior cavography can be achieved in