The liver has a complex vascular supply, which involves the inflow of oxygenated blood through the hepatic artery (systemic circulation) and deoxygenated blood through the portal vein (portal circulation), as well as the outflow of deoxygenated blood through the hepatic veins to the inferior vena cava. A spectrum of vascular variants can involve the liver. Some of these variants may result in areas of enhancement that can mimic more serious pathologic conditions. In this article, the authors discuss a spectrum of variants and pathologic conditions that may involve the liver vasculature. These include variants, anomalies, and diseases involving the portal vein, such as rudimentary portal vein, thrombosis, cavernous transformation, thrombotic angiitis, thrombophlebitis, transient hepatic attenuation difference or transient hepatic intensity difference, portal venous aneurysm, and portal vein gas. The hepatic artery can be involved by various diseases, including thrombosis, stenosis, and aneurysm or pseudoaneurysm. Unusual "third inflow" sources of venous inflow are also discussed, including aberrant right gastric vein, aberrant left gastric vein, epigastric-paraumbilical veins, and cholecystic vein. A spectrum of variants and diseases involving the inferior vena cava and hepatic veins, including thrombosis, Budd-Chiari syndrome, veno-occlusive disease, stenosis, torsion, congestive hepatopathy, and peliosis hepatis, are discussed. Vascular shunts are illustrated, including portosystemic shunts (intra- and extrahepatic), arterioportal shunt, shunts of hereditary hemorrhagic telangiectasia, and acquired arteriovenous fistula. Familiarity with the pathogenesis and imaging features of these vascular entities can aid radiologic diagnoses and guide appropriate patient management. RSNA, 2017.
