Evaluation of the Gross Type and Longitudinal Extent of Extrahepatic Cholangiocarcinomas on Contrast-Enhanced Multidetector Row Computed Tomography

Objective: The objective of this study was to determine the accuracy of contrast-enhanced multidetector row computed tomography (MDCT) in classifying the morphological subtype and revealing the longitudinal extent of extrahepatic cholangiocarcinomas (EHCs). Methods: Our institutional review board approved this retrospective study, and informed consent was waived. Two radiologists reviewed the preoperative MDCT images of 56 patients who had undergone surgical treatment of EHCs from 2000 to 2006. The reviewers classified the morphological subtypes and measured the enhancing segment of the bile duct with wall thickening on axial images; they then reviewed the axial and multiplanar reconstruction images of 39 patients. The image analysis results were compared with the pathological findings. Results: The accuracy of MDCT for morphological classification was 78.6% (44/56). The differences between the radiological and pathological measurements of the longitudinal extent of the tumors ranged from 0 to 53.5 mm, with a mean (SD) of 5.89 mm (11.42 mm). There was moderate correlation between the 2 measurements of the longitudinal extent of the tumors (P < 0.05, gamma = 0.4455). In 35 patients, MDCT measurements did not differ significantly from the pathological measurements (62.5%). In 18 patients, computed tomography (CT) underestimated the longitudinal extent of the tumor by more than 6 nun (32.1%). In the 39 patients with multiplanar reconstruction images, the correlation between the CT and the pathological measurements of the longitudinal extent was better in the combined interpretation of the axial and coronal images (P < 0.05, gamma = 0.4153) than that in the interpretation of only the axial images (P > 0.05, gamma = 0.2652). Conclusions: our results demonstrate that MDCT can correctly classify the morphological subtype of EHC. Nevertheless, CT has a strong tendency to underestimate the longitudinal tumor extent compared with the pathological results.