Appearance of Biphasic Spiral CT of Hemodynamic Change of the Primary Hepatocellular Carcinoma with Tumor Thrombus in Portal Vein

Objective To explore the appearances of biphasic spiral CT of hemodynamic Change of the primary hepatocellular carcinoma with tumor thrombus in ponal vein(PTT). Methods Twenty-seven patients with PTT who underwent dual-phase enhanced spiral CT were reviewed. The arterial phase( AP) images were obtained 20s after the initiation of injection of the contrast medium into the median cubital vein with automatic pressure injector,and the portal phase(PVP)were obtained after 60s.The CT findings were observed by three experienced radiologists together and formed a consensus interpretation. Results In the 27 cases, there were tumor thrombi of the main portal vein in 3 cases, right portal branch in 8 cases,left portal brandh in 9 cases,portal trunk with right portal branch in 3 cases,portal trunk with left portal branch in 2 cases, and tumor thrombi of portal trunk with left and right portal branch in 2 cases.Hepatic perfusion abnormalities were seen in the 27 cases, presenting as irregular patchy or pyamid-shaped hyperperfusion abnormality in AP and isodensity in PVP. Lobar, segmental and subseg-mental abnormalities were seen in 5,16 and 6 cases,respectively. Conclusion The possible explanations for the hyperperfusion abnonnalities is that the increased hepatic arterial flow caused by arterialization of a zone deprived of portal venous flow secondary to PTT.