Budd-Chiari syndrome: hepatic venous obstruction by an elevated diaphragm.

We describe two cases of Budd-Chiari syndrome detected by magnetic resonance imaging that resulted from compression of the inferior vena cava by an elevated right hemidiaphragm. Magnetic resonance images demonstrated elevation of the right hemidiaphragm and medial deviation of the inferior vena cava with short segmental narrowing. The hepatic veins and inferior vena cava were patent but discontinuous. Hepatic venous drainage was assisted by multiple large intrahepatic collaterals.