ObjectiveTo investigate the CT and MRI imaging features and differential diagnosis of IgG4-associated cholangitis(IAC).MethodsAltogether 15 patients who were confirmedly diagnosed as IAC in our hospital from January 2014 to June 2017 were selected as the subjects.The research was underwent CT plain scan and enhanced scan,MRI scan and enhanced scan as well as Magnetic Resonance Cholangiopancreatography (MRCP)examination.Statistical analysis of the examination results was made and all the patients received hormone therapy after examinations.Patients were followed up via telephone and outpatient.And the imaging data were evaluated.ResultsOf the 15 patients,10 patients received CT plain scan and enhanced scan,8 patients received MRI plain scan and enhanced scan,and 10 patients received MRCP examination.CT scan showed obvious thickening of the pancreatic duct wall of extrahepatic bile duct.Eccentric thickening of the bile duct wall in the upper part of the pancreas was also showed in some patients with progressive enhancement in bile duct wall.MRCP examination showed extrahepatic biliary pancreatic stricture,intrahepatic bile duct stricture and extrahepatic bile duct stricture were shown in a few patients.The follow-up results showed that 8 patients did not receive steroid treatment,and 3 patients had recurrent bile duct lesions after treatment,resulting in aggravation of the disease.In the rest of the patients,the lesions of the bile duct were obviously improved after steroid treatment.ConclusionThe imaging features of CT and MRI in patients with IgG4-associated cholangitis have obvious characteristics,which can provide reliable references for clinical diagnosis and differential diagnosis,it deserves attention.