Benign and Malignant Bile Duct Strictures

Imaging plays a crucial role in the evaluation of patients with biliary strictures such as in detection, characterization and treatment planning. MRCP is well-established for the detection of intra- or/and extrahepatic bile duct strictures as well as for the site, length and degree of stricture. For the differentiation of benign from malignant causes of biliary strictures and for treatment planning, MRCP/gadolinium-based contrast-enhanced (CE) MRI has been traditionally widely used. Diffusion-weighted imaging (DWI) has recently been implemented in clinical protocols. Literature data on its role in the evaluation of patients with bile duct strictures are somehow contradictory. The available studies are retrospectively designed and, in their vast majority, indicate that the addition of DWI to MRCP/CE-MRI contributes in the differentiation of benign from malignant causes of bile duct strictures as well as in the preoperative assessment of tumour extend. Furthermore, DWI has been shown to perform better than MRCP (and/or T2-weighted sequences) for the diagnosis of bile duct stricture of malignant aetiology.