Evaluation Of Anatomy Of Hepatic Vasculum And Clinical Application With MSCT Angiography

OBJECTIVE: To evaluate the rate of appearing of hepatic vasculum, the value of between hepatic vasculum and dividing of hepatic segment, and clinical application of between hepatic vasculum and diagnosing and treating of hepatic tumors according to imagings of hepatic artery, portal vein and hepatic vein shown by triple-phase scanning of 16-MSCT angiography.MATERIALS AND METHODS: A total of 175 patients underwent upper abdominal examinations using tripe-phase MSCT in our department. One hundred healthy subjects were observed. Liver neoplasms were detected in 75 patients, Hepatocellular carcinoma(HCC) was detected in 45 cases, cavernous hemangioma was in 15, hepatic adenoma was in 3 and metastases was in 12. Images were acquired following parameters: 120KV; 300mA; section thickness,1.0mm; pitch,15; pitch factor,0.938; sanning time of per rotation, 0.5s. All patients were administered 90-120ml(2ml/kg) of IV contrast material (ultravist,300mg I/mL) at an injection rate of 3ml/s. Automated bolus tracking using Sure-start software technique, the average scan delay time was 18-25s, 45-60s, 90-120s for arterial, portal venous and hepatic venous phase, respectively. All row data sets were reconstructed in 1-mm section and 0.5mm interval, and then were set to a workstation(Vitrea 2, Version 3.5, Toshiba)for maximum intensity projection(MIP) and volume rendering(VR) reconstruction. The Normal anatomy and variants of the hepatic vessels were classified in 100 cases and the relation of portal and hepatic venous systems for hepatic segmental anatomy was analyzed. Feeding arteries, draining veins and invaded vessels of hepatic tumor in 75 cases were analyzed and 30 cases of these patients were performed with DSA, including 20 of HCC and 10 of cavernous hemangioma. Delineating feeding arteries of hepatic tumor with MSCTA was compared with DSA in 30 cases.RESULTS:①Michels typeⅠ(Normal hepatic artery anatomy) was shown in 75 cases(75%), typeⅡin 6(6%), typeⅢin 3(3%), typeⅣin 2(2%), typeⅤin 4(4%), typeⅥin 1(1%), typeⅦin 1(1%), typeⅧin 2(2%), and typeⅨin 2(2%). There was no typeⅩ. However, four cases(4%) presented hepatic artery anatomic variations which could not be included in the Michels Classification.②Normal portal vein anatomy was shown in 76 cases(76%), typeⅡin 16(16%), typeⅢin 6(6%), and typeⅣin 2(2%).③TypeⅠof hepatic vein was present in 72 cases(72%), typeⅡin 22(22%), and typeⅢin 6(6%).④Segmental branches of portal vein supplied correspondingly hepatic segment, and hepatic vein and its branches located between adjacent hepatic segment. Branches of portal vein can crosses the adjacent hepatic vein.⑤Tumor vessels and feeding arteries of HCC were shown in hepatic arterial phase images in 42 cases. MSCTA was significant consistency with DSA in 20 of 42 cases and Arterio-venous fistula in 9 cases. In portal venous phase images, portal thrombosis were detected in 16 cases, venous occlusion in 5 cases. Feeding arteries of cavernous hemangioma were detected in 14 cases in arterial phase, which was completely consistent with DSA in 10 of 15. Draining veins and small branches were also found in portal venous phase. The enhancement pattern for hepatic adenoma in 3 cases were hypervas- cularity in arterial phase and feeding arteries were also found. Small feeding arteries of metastases were seen around lesions in 10 cases in arterial phase.CONCLUSION:①Triple-phase scanning with 3D 16-MSCTA is a significantly valuable method which can provide complete and comprehensive information on the hepatic vascular anatomy. Couinaud,s dividing of the liver in transaxial imaging had limitation. 3D angiography of portal and hepatic venous systems with MSCT can be applied to divide hepatic segment and subsegment accurately.②As a non-invasive and convenient method, 3D 16-MSCTA provides comprehensive vascular information of hepatic tumors, especially for detecting tumors,feeding arteries, draining veins and invaded vessels, and is good for diagnosis and therapy of liver tumor.