Hepatic perfusion disorders: Computer-tomographic and magnetic resonance imaging.

The liver has a unique dual blood supply from the hepatic artery (25%) and the portal vein (75%). Helical computer tomography (CT) and also magnetic resonance imaging (MRI) are suitable techniques for hepatic imaging. Helical CT and MR angiography allow single breath-hold scanning without motion artifacts. This article illustrates helical CT and MRI findings of different types of hepatic perfusion disorders. Because of rapid image acquisition, three-phase (hepatic arterial phase, portal venous phase and parenchymal phase) CT or MR-angiography evaluation of the hepatic parenchyma is possible, improving perfusion disorders evaluation, tumors detection and characterization in a single study. We classified hepatic perfusion abnormalities in: portal disorders, arterial disorders, hepatic veins abnormalities, intrahepatic vascular communication, hepatic lesions and perfusion disorders and other causes. Differential diagnosis and pitfalls of these entities must be known for a correct diagnosis of focal hepatic lesions.