Dynamic computed tomography and duplex ultrasonography: adjuncts to arterial portography.

The applications and limitations of contrast enhanced computed tomography (CT) in defining the extrahepatic portal system is discussed in the context of three separate cases in which the CT examination was used as an adjunct to an incomplete arterial portogram examination. Dynamic CT may be useful when excessive contrast dilution precludes the visualization of major venous structures during arterial portography. Real-time/pulsed Doppler ultrasonography is another complementary test but more limited in application than dynamic CT. Patency and flow direction in the proximal splenic vein, portal vein, and hepatic vein can be defined by the ultrasonic technique.