Background/purpose: The aim of this study was to compare the diagnostic accuracy of multidetector computed tomography (MDCT) and direct cholangiography in evaluating the longitudinal spread of extrahepatic bile duct cancer.
Methods: Images obtained from a 16-detector row scanner (MDCT) and from direct cholangiography (via either endoscopic naso-biliary drainage or percutaneous transhepatic biliary drainage) of 47 patients with histopathologically proven extrahepatic bile duct cancer were retrospectively interpreted. Differences between measures of longitudinal tumor spread determined by each modality and measures of macroscopic spread in resected specimens were assessed and compared.
Results: Assessments carried out using MDCT differed significantly less from the macroscopic measurements than those made using direct cholangiography (P < 0.0001). Provided the diagnosis was defined as being accurate, based on a diagnostic difference of within +/-5 mm, the diagnostic accuracy of MDCT (96%) was significantly higher than that of direct cholangiography (70%) (P = 0.028). Preoperative evaluation with direct cholangiography resulted in a 30% underestimation of the incidence.
Conclusion: MDCT is superior to direct cholangiography for evaluating the preoperative longitudinal extent of bile duct cancer. Consequently, the utility of MDCT for preoperative evaluation of extrahepatic bile duct cancer warrants further examination.