Preoperative evaluation of bile duct cancer: MRI combined with MR cholangiopancreatography versus MDCT with direct cholangiography

OBJECTIVE. The purpose of this study was to compare the performance of MRI combined with MR cholangiopancreatography (MRCP) with that of MDCT combined with direct cholangiography in the evaluation of the tumor extent and resectability of bile duct cancer with surgical and pathologic findings as the reference standard. MATERIALS and METHODS. From January 2003 to March 2006, 27 patients (18 men, nine women; mean age, 60.8 years; range, 43-80 years) with surgically proven hilar cholangiocarcinoma or common bile duct (CBD) cancer who had undergone preoperative 2D and 3D MRCP with gadolinium-enhanced MRI and triple-phase MDCT with direct cholangiography (ERCP or percutaneous transhepatic cholangiography) were included in this retrospective study. Two experienced radiologists independently reviewed the two image sets. These readers evaluated the longitudinal extent of the tumor for involvement of the secondary confluence of both intrahepatic ducts and the intrapancreatic CBD, vascular involvement of the tumor, lymph node metastasis, and tumor resectability. The radiologists' performance was evaluated by calculation of sensitivity, specificity, and overall accuracy. Correlation was made with the resected specimens or findings at surgical exploration. RESULTS. For each reviewer, the overall accuracy rates for predicting involvement of the bilateral secondary biliary confluences and the intrapancreatic CBD were 90.7% and 87.0% for MRI with MRCP and 85.1% and 87.0% for MDCT with direct cholangiography. The differences were not statistically significant for either image set for either reviewer (p > 0.05). In the assessment of vascular involvement, lymph node metastasis, and tumor resectability, the readers' diagnostic performance using MRI with MRCP was similar to that with MDCT with direct cholangiography (p > 0.05). CONCLUSION. In the diagnosis of bile duct cancer with a noninvasive procedure, the information regarding tumor extent and resectability obtained with contrast-enhanced MRI combined with MRCP is comparable with that obtained with MDCT with direct cholangiography.