| [Objective]l.To investigate the showing ability of the three-dimensional dynamic contrast-enhanced MRA and a study was undertaken to determine the anatomy and variations of the portal vein.2. To assess the value of clinical applications of 3D DCE MRP in the diagnosis and surgery of lesion of the portal vein and its major branches.[Meterials and Methods]1. 3D DCE MRP was performed in 133 cases. The imaging sequence was three-dimensional fast imaging with steady-state procession(3D FISP), and the used parameters were TR:2ms,TE:5ms,flip angle 20? and matrix 192 X 256. The 0.2~0.3mmol/Kg Gd-DTPA was injected with the rate of 2~3ml/sec, and the scan delay time was determined on the basis of the result of bolus test and the images were reconstructed with maximum intensity projection(MIP).2. 61 3D DCE MRP were effective and the image quality was evaluated by analyzing the demonstration of the portal venous system and the display of the right portal vein on 3D DCE MRP. The main branches in portal venous system were measured in 51 normal 3D DCE MRP and 61 3D DCE MRP of the portal system were analyzed, the normal anatomy of these venous systems was determined, variations of the intrahepatic portal vein were classified and the percentage of each variation was calculated.3. 3D DCE MRP of 72 cases of portal vein system diseases were analyzed including innate portal diseases 2 cases, portal hypertension 19 cases, hepatocellular carcinomas 33 cases, portal vein thrombosis 2 cases, Budd-Chiai syndrome 5 cases, other diseases 6 cases and pre- or post-operation of portal hypertension and liver transplantation 13 cases. To sum up the 3D DCE MRP signs of these diseases, and to evaluate the veracity of 3D6DCE MRP in displaying portal vein system diseases by comparison to 29 cases of DSA, 1 case of CTA or/and 21 cases of surgery.[Results]1. Peak transit time of portal vein was 17~35sec. The visulization rates for the main portal vein(MPV), left and right portal vein(LPV, RPV), splenic vein(SPV) and superior mesentery vein(SMV) were 96.7%, 81.7% and 90.0%, 93.3% and 88.3%. The main portal vein and its fourth-order branches were showed without disruption in 61 cases. Of the 61 patients examined, 4(6.6%) had trifurcation, 3 (4.9%) had a right posterior branch arising from the main portal vein first and then the right anterior and left portal vein originating from the ascending main portal vein, 2 (3.3%) had a right anterior branch from the left portal vein, 1 (1.6%) had the absence of the right portal vein. The remaining 51 (83.6%) patients had normal distribution of the intrahepatic portal vein.2. 3D DCE MRP displayed the signs of portal vein system diseases much better.(l) Innate portal diseases(n=2): Abernethy syndrome(n=l), Portal aneurysm(n=l). 3D DCE MRP demonstrated the type of variations in the portal vein and the process of diseases. (2) Portal hypertension(PHT): MPV, LPV, RPV, SPY and SMV were larger in PHT than those of control respectively, the differences of MPV and decreased sub-branching of portal vein between Child A and B patients were not significant. Positive imaging cases of variceal veins in PHT were obtained significantly. (3) hepatocellular carcinomas(n=33): 41 involved portal vein with tumor thrombus were detected by 3D DCE MRP, the embolism cases presented filling defect likenodes in 24 and irregular in 17, the thrombus lead to dilation of involved vein in 23 and unsuccessive lines in 11. The sensitivity and specificity and accuracy of 3D DCE MRP diagnosing the portal tumor thrombus are 91.9% and 88.7% and 89.8%. Furthermore, 12 portal cavernous transformation and 6 artery-portal shunt were detected in our study, the characteristic MRPfeatures of portal cavernous transformation were depicted as loss of the normal architecture of the portal system and the presence of a snakelike network of intertwined veins; and the features of artery-portal shunt manifested "Double sign"(n=2) and early visualization of the sub-segmental or more proximal portal branches(n=4). (4) Portal vein thrombo...
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