Differentiation of Extrahepatic Cholangiocarcinoma from BenignBile Duct Stricture: Usefulness of Helical Computed Tomography

Han, Seung Min; Jeong, Yong Yeon; Chung, Tae Woong; Shin, Sang Soo; Heo, Sook Hee; Choi, Song; Kang, Heoung Keun

Abstract

We tried to compare the findings of helical CT in patients with malignant stricture in extrahepatic bile duct caused by infiltrating cholangiocarcinoma and benign stricture. Subjected to this study were 31 cases of extrahepatic biliary stricture comfirmed by pathology or follow up of imaging study (15 malignant and 16 benign) during 4 years. Helical CT during both hepatic arterial and portal phase was performed in all patients. CT findings were analyzed retrospectively about thickness of lesion, upstream extrahepatic bile duct diameter, enhancement pattern of lesion, asymmetric wall thickening and abrupt luminal narrowing by two radiologists in consensus. Thickness of lesion in malignant stricture (4.0 mm+/-1.8) was greater than that in benign stricture (1.7 mm+/-0.6) (p<0.001). During both hepatic arterial and portal venous phase, higher attenuation was observed more frequently in malignant strictures than in the normal CBD (arterial phase; p=0.049, portal phase; p=0.006). Asymmetric wall thickening and abrupt luminal narrowing were also observed more frequently in malignant stricture (p<0.001). In differentiation of malignant stricture caused by infiltrating extrahepatic bile duct cholangiocarcinoma from benign stricture, thickness of lesion, high attenuation of lesion during hepatic arterial or portal phase, asymmetric wall thickening and abrupt luminal narrowing are thought to be the significant findings.