Preoperative staging accuracy of multidetector row computed tomography for extrahepatic bile duct carcinoma

PURPOSE: This study sought to evaluate the accuracy of multidetector computed tomography (MDCT) for preoperative staging of extrahepatic bile duct (EHD) carcinoma and to assess the value of coronal reformations from isotropic voxels. MATERIALS AND METHODS: Thirty patients with surgically proven EHD cancer underwent dynamic MDCT with coronal reformation. Two experienced radiologists independently evaluated contrast-enhanced dynamic transverse CT images (axial approach) and combined transverse and coronal images (combined approach). The radial extent (TNM staging) and the vertical extent of tumors were assessed and correlated with pathological findings of surgical specimen. RESULTS: All of primary tumors were detected by axial and combined CT imaging (100%). Overall accuracy of the T staging was 73% (22/30) with axial and 77% (23/30) with combined CT imaging (P > 0.05). The accuracy of N staging was 57% (17/30) with axial and 63% (19/30) with combined CT imaging (P > 0.05). The accuracy of M staging was 97% (29/30) with both axial and combined CT imaging.Upper margin accuracy was 97% (29/30) for axial and 100% for combined CT imaging (P > 0.05), whereas that of the lower margin was 90% (27/30) for axial and 93% (28/30) for combined CT imaging (P > 0.05). CONCLUSIONS: Multidetector computed tomography was sufficiently accurate for evaluating the vertical extents, but radial extents of EHD cancer. The addition of coronal reformatted images did not improve the accuracy for staging of EHD cancer.