Purpose: To compare the diagnostic accuracy of MR cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of malignant stenosis of the distal common bile duct.
Materials and methods: Twenty-one patients (12 males and 9 females, mean age 62 years) with a clinical suspicion of malignancy of the distal biliary tract and pancreatic head underwent tomographic RM evaluation and diagnostic MRCP, followed by diagnostic and, where possible, therapeutic ERCP. The images obtained with ERCP and MRCP were reviewed blind by two experts who evaluated the presence, site, signal features and locoregional extension of the tumours. Histology performed by brushing or biopsy during ERCP and after surgical resection provided the standard of reference for all 21 patients.
Results: CPRM correctly identified the presence and site of the distal biliary stenosis in 21/21 (100%) cases, as well as allowing evaluation of the upper abdomen by associating it with conventional MRI. ERCP, instead, allowed detection of the presence and site of biliary stenosis in 20/21 (95%) cases.
Discussion and conclusions: ERCP may have some limitations as regards identification of distal bile duct stenosis in cases of critical stenosis. The non-invasive nature and panoramic capabilities of MRCP and the fact that no contrast material is needed make MRCP the examination of reference in the diagnosis of malignant stenosis of the distal bile duct, also thanks to its ability to visualise the entire biliary tree in the presence of critical strictures of the common bile duct. The rationale for the use of ERCP lies in the possibility of taking histological samples and performing minimally invasive surgical interventions.