ObjectiveTo investigate the clinical value of MRCP and (or) MRI on combination of choledochoscopy and duodenoscopy during the course of therapeutic laparoscopy with preoperative or intraoperative help diagnosis and treatment of gallbladder stone with common bile duct stones of diameter in the normal range. MethodsThe clinical data of 998 patients with calculus of bile duct with diameter in the normal range of common bile duct (common bile duct diameter of 0.2-0.8 cm) by MRCP and (or) MRI assist in diagnosis and treatment from Oct. 2001 to Dec. 2015 in the Second People's Hospital of Chengdu City were retrospectively analized. ResultsThe 998 cases of common bile duct diameter≤0.8 cm were diagnosed and treated by using MRCP and (or) MRI examination. Choledochoscopy group: There were 399 cases, 352 cases (88.2%) were successful removed the bile duct residual stones through the choledochoscopic procedure, converted to intraoperative endoscopic sphincterotomy in 47 cases (11.8%). The false positive rate of MRCP and (or) MRI was 3.7% (13/352), the false negative rate of color Doppler ultrasound was 79.3% (279/352). Duodenoscopy treatment group: It was performed in 408 cases. The stones of common bile duct removed with duodenoscopic papillo-tomy in 381 cases (93.4%), the stone expulsion after duodenoscopic papillotomy in 18 cases (4.4%), 9 cases (2.2%) were shifted to other operation. False negative rate of color Doppler ultrasound was 79.5% (303/381). Three endoscopy group: There were 191 cases that intraoperative choledochoscopic exploration or intraoperative endoscopic papillotomy. The false positive rate of MRCP and (or) MRI was 2.6% (5/191), the false negative rate of color Doppler ultrasound was 76.4% (146/191). ConclusionsRoutine use of MRCP and MRI, in preoperative or intraoperative help diagnosis and treatment of gallbladder stone with common bile duct stones of diameter in the normal range, on combination of choledochoscopy and duodenoscopy during the course of therapeutic laparoscopy. It is necessary, feasible, effective and safe.