Imaging assessment of congenital and acquired abnormalities of the portal venous system.

Abnormalities of the portal venous system are a heterogeneous group of conditions that can cause substantial morbidity and mortality and may lead to complications during surgery or percutaneous interventions involving the portal venous system. High-resolution computed tomography, ultrasonography, and magnetic resonance imaging permit a comprehensive, noninvasive evaluation of the portal venous system, enabling the detection of both structural and functional abnormalities. However, an understanding of the embryologic development of the normal portal venous anatomy and anatomic variants is essential to accurately interpret the imaging findings. Knowledge of the characteristic appearances of abnormalities of the portal venous system allows a more confident diagnosis, permitting timely treatment and more informed guidance of surgical procedures and percutaneous interventions, which may lead to an improved outcome.