Role of multidetector computed tomography in differentiating benign and malignant common bile duct strictures

Objective: To evaluate the diagnostic features in differentiating malignant from benign common bile duct (CBD) strictures using contrast-enhanced multidetector computed tomography (MDCT). Patients and Methods: An ambispective study from January 1, 2008 to December 31, 2010, on fifty patients with liver function tests suggestive of obstructive jaundice and an ultrasound showing biliary obstruction were included. A nonenhanced computed tomography (CT) was done before the administration of the contrast medium and then scans were routinely obtained in four phases: early arterial , late arterial, portal venous, and delayed phases. The CT scans acquired were reviewed on a picture archiving and communication system workstation. CT findings were interpreted with regard to wall thickness, the location, length involved, enhancement pattern, presence of invasion, and margins of the stricture. These were compared with the attenuation of the normal CBD wall, the maximum CBD diameter proximal, and pancreatic duct dilatation. Results: The mean age ± standard deviation of patients was 62.84 ± 11.61 years (range: 38–82 years). Among the fifty patients included in the study, 31 (62%) had malignant CBD stricture. The involved segments of malignant CBD strictures were significantly longer with significantly larger maximum proximal CBD diameter, considerably thicker and irregular stricture wall and showing more enhancement during delayed phase. No significant differences were found between malignant and benign CBD strictures with respect to stricture location. Conclusions: Presence of irregular margins, invasion into neighboring tissues, long-segment involvement, more proximal CBD dilatation, and hyperenhancement in delayed and portal venous phases in contrast-enhanced MDCT helps in the differentiation of malignant from benign CBD strictures.