The 3D MRA Techniques And The Application In Analyse The Anatomy And Variations Of The Intrahepatic Portal Vein And Hepatic Veins

PURPOSE: (1)To compare the advantages and limitations of twothree-dimensional magnetic resonance angiography sequences--------Volumetric Interpolated Breath-hold Examination (VIBE) and True Fast Imaging Steady-state Precession(TrueFISP) in intrahepatic portal vein and hepatic veins imaging; (2)to analyze the anatomy and variations of the intrahepatic portal vein and hepatic veins in normal Chinese and their impact on segmentation of the liver and surgical planning.MATERIALS AND METHODS: 100 patients underwent the upper abdominal MRA examination in our department during a 9-month period. To sample 40 patients and randomly grouping into A and B group. All the patients in two groups underwent the precontrast TrueFISP and postcontrast VIBE and TrueFISP examinations, but the scan order of the enhanced sequences is different between two groups. Before the enhanced scan ,the delay times of patients in two groups must be obtained through the Test bolus examination. The rest 60 patients only get three phases 3D VIBE scan. To compare the image quality of the three sequences in two groups by One-Way ANOVA and T Test. The qualitative assessment standards includeclarity, artifacts, signal uniformity, the conspicuity of enhanced vein and the observable grade of intrahepatic venous branchs. The quantitative assessment standards include SNR and CNR of intrahepatic portal vein and hepatic veins. Furthermore, the anatomy and variations of the intrahepatic portal vein and hepatic veins are statistical analysed.Results: For aortic ghosting, the scores of c-TrueFISP and c+TrueFISP of two groups are lower than c+VIBE, p<0.05. For the observable grade of intrahepatic venous branchs, the score of c+TrueFISP of two groups is higher than the others, p<0.05. For the conspicuity of hepatic veins, the score of c+TrueFISP is higher than c+VIBE in A group, p<0.05, and for the conspicuity of intrahepatic portal vein, the score of c+TrueFISP is higher than c+VIBE in B group, p<0.05. The compares between two groups indicate the score of the conspicuity of intrahepatic portal vein of c+VIBE in A group is higher than the score in B group, however, the score of the conspicuity of hepatic veins is lower than B group. No significant difference was found among the two groups with regard to other standards. The rates of type I, typell, type III and type IV of intrahepatic portal vein are 82%, 11% , 5%, 2% respectively. The rates of type A, type B and type C of hepatic veins are 71 %, 25%, 4%respectively. There is common trunk in 51% of all the cases. The occurrence rate of inferior right hepatic veins is 29%, dia.5-llmm.CONCLUSION: Both of VIBE and TrueFISP sequences can get the optimal 3D MRA image of the intrahepatic portal vein and hepatic veins and consequently provide details of segmentation and vascular anatomy to facilitate treatment planning.