Background Budd-Chiari syndrome with hepatic vein occlusion (HVBCS) can induce severe portal hypertension and liver damage. We retrospectively analyzed hepatic CT features of HVBCS and evaluated the usefulness of triphasic enhancement of CT examinations and CT angiography (CTA) in its diagnosis.Methods Twenty-five cases with HVBCS, confirmed by digital subtraction angiography (DSA), received a triphasic enhancement CT scan within one week before DSA. The CTA images of the relevant blood vessels were reconstructed with maximum intensity projection, volume rendering and oblique reformat techniques.Results Compared with DSA, the detection rate of transverse CT and CTA images for abnormal hepatic vein were 81.7% (58/71) and 95.8% (68/71) (χ2=7.044, P=0.008), for membranous obstruction were 47.4% (9/19) and 84.2% (16/19) respectively (χ2 =5.729, P=0.017 ), for segmental obstruction were 88.0% (22/25) and 100% (25/25) respectively (χ2=1.418, P=0.234). The detection rates for hepatic vein stenosis were 100% with each method. Diffuse hepatomegaly was found in all 6 cases in acute phase and 3 of 19 cases in chronic phase who had severe obstruction of three hepatic veins without patent intrahepatic collaterals. The other 16 cases in chronic phase had hepatatrophia to different extents related to the obstructed hepatic vein. All in acute phase and 15 in chronic phase presented typical patchy enhancement initially in caudate lobe and perihilar areas and enlarged with time delay. In all cases, parenchyma areas with atrophy, necrosis and congestion demonstrated lower and later enhancement. In all the parts, which had normal enhancement at least one patent outflow hepatic vein, accessory hepatic vein or collateral vessel was detected. Conclusion Dynamic enhancement CT examination by multislice spiral CT not only could improve the diagnosis of HVBCS by CTA technique, but also could noninvasively provide anatomical information and reveal damage to the hepatic parenchyma.