The ultrasonic demonstration of inferior vena caval compression: a guide to pancreatic head enlargement with emphasis on neoplasm.

The ultrasonic demonstration of compression of the anterior (ventral) wall of the inferior vena cava by the pancreatic head was proved to be a reliable sign of neoplasm enlarging the pancreatic head in 10 patients. It would appear that this sign is less reliable and probably not as important diagnostically in patients with pancreatic head enlargement secondary to pancreatitis or pseudocyst. This sign must be constant and reproducible on longitudinal scans done with a single transducer pass in suspended inspiration. This sign was not seen in 50 patients who had no evidence of pancreatic disease.