Budd-Chiari syndrome: a review of imaging findings.

Budd-Chiari syndrome is an uncommon, often fatal disorder resulting from an obstructed hepatic venous outflow tract. The obstructive lesion is situated in the main hepatic veins, in the inferior vena cava or in both. The nature, location and extension of the obstruction can be displayed on diagnostic imaging techniques. In addition to this direct evidence, the indirect findings of venous obstruction such as the presence of intra- and extrahepatic collateral veins, when combined with the altered morphology and enhancement pattern of the liver enables one to arrive at a confident diagnosis. In patients with suspected Budd-Chiari syndrome, gray-scale sonography with complementary support of color and pulsed Doppler examinations is the first step in approaching the diagnosis. It is followed by a contrast-enhanced cross-sectional technique, preferrentially by MR angiography. The patients with a high clinical suspicion of Budd-Chiari syndrome may undergo hepatic venography or venacavography directly so that a potential of recanalization (e.g. percutaneous transluminal angioplasty with or without stent placement or TIPS) of the obstructed segment under the guidance of these techniques would not be delayed.