CT and MRI of acquired portal venous system anomalies.

In this educational presentation, we offer an overview of acquired anomalies of the portal venous system explored by biphasic helical CT and MRI. Portosystemic collateral vessels, cavernous transformation of the portal vein, intrahepatic vascular shunts, aneurysms of the portal venous system, thrombosis of the portal venous system, and gas in the portal venous system will be discussed. For liver surgery and interventional procedures it is necessary to have a correct mapping of normal anatomy, variants, and different pathologies involving the portal venous system.