Objective：To evaluate computed tomography（CT） or magnetic resonance imaging（MRI） findings of annular pancreas in the adults in order to improve the recognition. Methods：Six adult patients with annular pancreas were retrospectively analyzed. Three cases received plain and contrast-enhanced CT scanning while the other three cases received plain and contrast-enhanced MRI scanning. Among them，one case undertaken magnetic resonance cholangiopancreatography examination. The CT and MR images were reviewed by two radiologists blindly and consensus agreement was reached. Results：Both CT and MRI findings can detect annular pancreas by visualizing not only the direct sign but also the indirect sign. The imaging findings of all cases were extension of pancre－atic head which encircled the second portion of the duodenum. The indirect signs included dilation of the intrahepatic bile duct（two cases），the common bile duct（three cases） and the Wirsung duct（four cases），pancreatitis（one case） and cholecystitis（one case）.Conclusions：CT plain and enhanced scan can be a pivotal method in the diagnosis for annular pancreas in adults by demonstrating the morphologic features clearly.
