Magnetic Resonance Imaging Findings of Portal Biliopathy

PURPOSE: We wanted to evaluate the MR imaging findings of portal biliopathy. MATERIALS AND METHODS: We retrospectively reviewed the MR imaging of twelve patients having biliary abnormalities and portal cavernoma. Two radiologists working in consensus analyzed the presence of extrahepatic portal vein obstruction, cavernous transformation, portosystemic collaterals and bile ducts abnormalities that included irregular contour, stricture, ductal dilatation, wall thickening and enhancement of the ductal wall. RESULTS: Extrahepatic portal vein obstruction was replaced by cavernous transformations in all patients. The cavernous transformations depicted on the MR scans were paracholedochal veins in 12 patients and epicholedochal veins in 6 patients. Three different types of biliary abnormalities were present: 1) the pseudocholangiocarcinoma type (3 patients) that resembled extrahepatic cholangiocarcinoma, 2) the varicoid type (6 patients) that was mainly distinguished by the multiple smooth extrinsic impressions along the common bile duct and 3) the mixed type (3 patients). The highly specific findings for the pseudocholangiocarcinoma type disease were thickening and delayed enhancement of the biliary ductal wall. CONCLUSION: The MR findings of portal biliopathy include cavernous transformation of the portal vein and morphological alterations of the biliary tracts such as irregular contour, biliary stricture with proximal ductal dilatation and thickening of the ductal wall with delayed enhancement. Recognition of these MR findings should facilitate the accurate diagnosis of portal biliopathy and prevent the misinterpretation or inappropriate management of this disease as malignancy or sclerosing chloangitis.

MR Imaging of Portal System: Comparison between True-Fast Imaging with Steady State Precession(FISP) and Enhanced Fast Low Angle Shot(FLASH) Imaging

PURPOSE: The purpose of this study was to compare true-fast imaging with steady state precession(t-FISP) with enhanced fast low-angle shot(e-FLASH) imaging of the abdomen in the assessment of the normal and abnormal portal venous(PV) system. MATERIALS AND METHODS: In order to evaluate the PV system, MR images using both t-FISP and e-FLASH sequences were obtained in 62 patients with hepatic mass. In 56 cases in which PV thrombosis was not demonstrated, images were evaluated for homogenity and artifacts within the lumen of the PV system and the margin of the main PV. In the other six cases of PV thrombosis, conspicuity and extent of the thrombus were also compared . RESULTS: For each vessel, the mean score for homogeneity and artifacts was significantly higher in t-FISP images than in e-FLASH images(P<.05), as were mean scores for the margin of the main PV (P < .05). In six patients with PV thrombosis, conspicuity of the thrombus as seen on t-FISP images was superior to that seen on e-FLASH images; similarly, the exact extent of the thrombus was more accurately defined on the former type of image. CONCLUSION: For evaluation of the PV system, t-FISP MRI provides better imaging quality and better conspicuity with regarded to the site and extent of PV thrombus, as compared with e-FLASH images.

MR Imaging of Portal System: Comparison between True-Fast Imaging with Steady State Precession(FISP) and Enhanced Fast Low Angle Shot(FLASH) Imaging

PURPOSE: The purpose of this study was to compare true-fast imaging with steady state precession(t-FISP) with enhanced fast low-angle shot(e-FLASH) imaging of the abdomen in the assessment of the normal and abnormal portal venous(PV) system. MATERIALS AND METHODS: In order to evaluate the PV system, MR images using both t-FISP and e-FLASH sequences were obtained in 62 patients with hepatic mass. In 56 cases in which PV thrombosis was not demonstrated, images were evaluated for homogenity and artifacts within the lumen of the PV system and the margin of the main PV. In the other six cases of PV thrombosis, conspicuity and extent of the thrombus were also compared . RESULTS: For each vessel, the mean score for homogeneity and artifacts was significantly higher in t-FISP images than in e-FLASH images(P<.05), as were mean scores for the margin of the main PV (P < .05). In six patients with PV thrombosis, conspicuity of the thrombus as seen on t-FISP images was superior to that seen on e-FLASH images; similarly, the exact extent of the thrombus was more accurately defined on the former type of image. CONCLUSION: For evaluation of the PV system, t-FISP MRI provides better imaging quality and better conspicuity with regarded to the site and extent of PV thrombus, as compared with e-FLASH images.