MDCT cholangiography with volume rendering for the assessment of patients with biliary obstruction

OBJECTIVE. We sought to evaluate the diagnostic utility of MDCT cholangiography with volume rendering in the evaluation of patients with suspected biliary tree obstruction. SUBJECTS AND METHODS. MDCT was performed in 34 patients who were thought to have biliary obstruction. Portal venous phase scanning was initiated 70 sec after the IV infusion of 150 mL of contrast agent, and no cholangiographic contrast agent was administered. Three-dimensional MDCT cholangiographic images were produced using volume rendering. ERCP was performed in 26 patients, and percutaneous transhepatic cholangiography (PTC) was performed in five patients; 17 patients underwent biopsy or surgery. The findings on MDCT cholangiography were compared with those of ERCP, PTC, biopsy, or surgery. RESULTS. The correct diagnosis was made on MDCT cholangiography for 14 (93%) of the 15 patients with a biliary stone and in 16 (94%) of the 17 patients with malignant biliary obstruction. Microlithiasis in one patient could not be detected on MDCT cholangiography. One patient with polypoid adenocarcinoma and one patient with normal findings were incorrectly diagnosed with a biliary stone on the basis of MDCT cholangiography. In one of the two patients with a benign stricture, the stricture was incorrectly diagnosed as malignant. For the diagnosis of biliary stone, sensitivity and specificity of MDCT cholangiography were 93% and 89%, respectively. For the diagnosis of malignant obstruction, sensitivity and specificity were both 94%. The accuracy of the technique for the diagnosis of the cause of biliary obstruction was 83.3%. CONCLUSION. MDCT cholangiography with volume rendering is a noninvasive and fast imaging technique with high sensitivity and specificity for the diagnosis of the cause of biliary tree obstruction. It is a promising diagnostic tool for the assessment of patients with bile duct obstructions.