Abstract: Objective The aim of this study was to explore the diagnostic efficacy of ultrasonography, CT and magnetic resonance cholangiography (MRCP) in the diagnosis of extrahepatic bile duct stones.Methods A total of 107 patients with extrahepatic biliary obstruction were recruited in our hospital between March 2017 and February 2019, and all of them underwent abdominal ultrasonography, CT scan and MRCP. The diagnosis was confirmed by pathological examination. The diagnostic sensitivity, specificity and accuracy by abdominal ultrasound, CT and MRCP for diagnosis of stones were analyzed by ROC curves and the area under the ROC curve (AUC).Results Out of our 107 patients with extrahepatic biliary obstruction, 59 were diagnosed as with extrahepatic bile duct stones by post-operational pathological examination and the diagnostic rates by ultrasonography, CT and MRCP were 64.4%,67.8% and 84.7%(P<0.05); as to the stones less than 8 mm, the diagnostic rate by MRCP was 80.0%(32/40), significantly higher than 60.0%(24/40) by ultrasonography or 57.5%(23/40) by CT scan, and the accuracy of positioning stones by MRCP was 84.8%(50/59), also much higher than 66.1%(39/59) by sonography or 67.8%(40/59, P<0.05) by CT scan; the diagnostic sensitivity, specificity and accuracy by MRCP were 84.8%(50/59), 89.6%(43/48) and 86.9%(93/107), significantly higher than64.4%(38/59), 83.3%(40/48) and 72.9%(78/107) by sonography (P<0.05) or 67.8%(40/59), 81.3%(39/48) and 73.8%(79/107) by CT scan (P<0.05). Conclusions The diagnostic efficacy of MRCP in detecting extrahepatic bile duct stone is superior to ultrasonography or abdominal CT scan, especially for stones less than 8 mm, which has a very practical roles in clinical practice.

Key words: Extrahepatic bile duct stone, Magnetic resonance cholangiography, Computed tomography, Diagnosis