Differentiation between Infiltrative Cholangiocarcinoma Strictures and Benign Common Bile Duct Strictures Using Multi-Slice Computed Tomography (MDCT)

Objectives: To evaluate CT scan features for differentiating infiltrative cholangiocarcinoma (CC) strictures from benign common bile duct (CBD) strictures. Methods: CT images of 30 patients with infiltrative CC strictures and 20 patients with benign CBD strictures were reviewed retrospectively by two radiologists. CT features were analyzed regarding location, length of ductal stricture, maximum ductal diameter proximal to stricture, ductal wall thickness, ductal wall enhancement in arterial dominant and portovenous phases, stricture pattern (abrupt vs tapering), and symmetry vs asymmetry. CT features were compared by the chi-square test and the Fisher exact test for descriptive factors, and compared by independent T-test and Kruskal Wallis test for lengths of bile duct stricture and maximal ductal diameters. Results: Malignant strictures due to infiltrative CC were significantly longer than benign strictures (median 16.8 mm vs 4.0 mm, p < 0.0001). Ductal diameters proximal to strictures were significantly larger in CC than those of benign strictures (median 17.0 mm vs 10.0 mm, p < 0.0001). Infiltrative CC strictures exhibited more involved ductal thickness, hyperenhancement of ductal wall in both arterial dominant and portovenous phases, and abrupt and asymmetrical narrowing pattern compared to benign CBD strictures (p < 0.0001). Conclusions: CT can help with differentiation between infiltrative CC and benign CBD strictures.