Abstract: Objective To investigate the magnetic resonance imaging （MRI） and computed tomography（CT） features of clonorchiasis-associated cholangiocarcinoma, and provide reference for its clinical diagnosis. Methods The CT and MRI （including magnetic resonance cholangiopancreatography, MRCP） data of 60 patients diagnosed to have cholangiocarcinoma（26 cases with clonorchiasis-associated cholangiocarcinoma, group A; 34 cases with simple cholangiocarcinomas, group B） by surgery or biopsy in two hospitals in Guangdong Province during July 2005 and June 2015 were collected. The tumor location, pathological types, imaging features, mode of enhancement, and the bile duct expansion were analyzed. Results Imaging results showed that the tumor tended to occur in the right liver in group A（46.2%, 12/26） and in the left hepatic duct and the liver explorer in group B （61.8%, 21/34）（P<0.05）. The pathological types of tumor in both groups included the nodule/mass type（group A, 73.1%, 19/26; group B, 52.9%, 18/34）, the infiltration type （15.4%, 4/26; 23.5%, 8/34）, and the cavity growth type（11.5%, 3/26; 23.5%, 8/34）（P>0.05）. Plain and enhanced CT and MRI results revealed no significant difference in tumor density, signal characteristics or the mode of enhancement between the two groups. MRCP results showed that the intrahepatic distal bile duct cystic dilatation, the intrahepatic bile duct cane soft tubular ectasia, the bile duct dilatation in the tumor, and the bile duct dilatation surrounding the tumor accounted for 61.5%（16/26）, 19.2% （5/26）, 50% （13/26） and 7.7%（2/26） in group A, and 8.8% （3/34）, 64.8% （22/34）, 20.6% （7/34） and 38.2% （13/34） in group B （P<0.05 for each of the four）， respectively. Conclusion The clonorchiasis-associated cholangiocarcinoma has certain imaging characteristics. It is different from the simple cholangiocarcinomas in tumor location and intrahepatic bile duct dilatation.

Key words: Clonorchiasis, Cholangiocarcinomas, Liver, CT, Magnetic resonance imaging, Magnetic resonance cholangiopancreatography