Duplex Doppler examination of the liver and portal venous system.

Duplex Doppler scanning has many applications in the evaluation of the liver and the portal venous system. It can be a useful adjunct to real-time sonographic identification of normal and variant anatomy, and lesion detection in the liver and porta hepatis. It is able to document both portal venous thrombosis and portal venous hypertension. It plays an important role in the pre- and postoperative assessment of patients undergoing portosystemic shunts or liver transplants. It allows the observation and measurement of portal venous systemic physiologic responses. In addition to the above applications, duplex Doppler scanning's future potential, including full-field color Doppler imaging, is discussed.