Inferior vena cava hypoplasia with intrahepatic venous continuation: sonographic, angiographic and MR features including MR angiography.

In cases of inborn or acquired obstacles on the inferior vena cava (IVC), the derived blood flow usually goes through collaterals in the azygos or the hemiazygos venous systems. Exceptionally, a collateral pathway through the portal system or through an anastomosis in between hepatic veins, shunting the IVC interruption, is encountered. In the present paper, the authors describe the fortuitous discovery of a IVC hypoplasia in its retrohepatic segment. MR venography, correlated with fluoroscopic angiography, clearly depicted an intrahepatic collateral circulation consisting of a double aneurysmal communication between an inferior right hepatic vein and the main right hepatic vein.