Comparative study on MRI features of acute and chronic Budd-Chiari syndrome

Objective: To investigate the features of Magnetic resonance imaging (MRI) and analyze the diagnostic value of MRI on acute and chronic Budd-Chiari syndrome(BCS). Methods: Eleven patients with acute BCS who were treated, while other 42 patients with proven chronic BCS were taken as chronic group. All patients in our study underwent MRI examinations. MRI findings were retrospectively studied. Comparison between groups was made by Wilcoxon W rank sum test for frequency of ascites and Fisher Exact Test for the percentage of intrahepatic venous collaterals and extrahepatic venous collaterals. Results: Hepatic venous thrombosis with high signal on T₂WI was demonstrated in 11 patients with acute BCS, and 3 of them also had inferior vena cava thrombosis. Compared with the central liver, the periphery of the liver of all patients were moderately hypointensive on T₁WI and slightly hyperintensive on T₂WI, and the enhancement degree of liver periphery in venous phase and arterial phase was relatively low. In chronic group, 9 of them had hepatic venous obstruction, 3 had inferior vena cava obstruction, and 30 had both. All chronic BCS patients had the features of stasis cirrhosis. There was no signal difference between the periphery and the central of the liver on precontrast and postcontrast images. In acute group, all of them suffered from ascites (2 patients with a moderate amount of ascites, and 9 patients with massive ascites), 2 of them had intrahepatic venous collaterals, one had extrahepatic venous collaterals. But in chronic group, 22 of them suffered from ascites (A small amount of ascites in 15 patients, 2 patients had a moderate amount of ascites, and 5 patients had massive ascites) 7 and 37 of them were found with intrahepatic venous collaterals, 34 of them were with extrahepatic venous collaterals. The incidence of ascites in the acute group was higher than that in the chronic group (Z = 4.15, P < 0.01), and the percentage of intrahepatic venous collaterals and extrahepatic venous collaterals in the acute group were lower than the chronic group (P < 0.01). Conclusion: MRI can show the direct and indirect features of BCS, which is not only helpful to diagnose BCS, but also to judge the stage of BCS. (authors)