Analysis of CT and MRI Manifestations of peripheral Nodular Cholangiocarcinoma

Objective:To analyze the CT and MRI manifestations of peripheral nodular cholangiocarcinoma correlated with pathology.Methods:Of the fifteen cases with pathology proved peripheral nodular cholangiocarcinoma,11 cases underwent multiphase spiral CT scan without and with contrast enhancement,6 cases(2 of them had concurrent CT scan) underwent plain and dynamic enhanced MR examination.All the imaging features were correlated with pathology findings.Results:Of the 15 cases,totally 19 lesions were revealed,with the longest dimension ranged from 1.1cm to 4.9cm(average,2.8±1.4cm),distributed in either left or right hepatic lobe.Unenhanced CT scan of 11 cases revealed totally 15 lesions,Totally 15 lesions were detected by CT.After contrast administration,14 lesions demonstrated peripheral enhancement on arterial phase and fill-in toward the center on portal venous phase,which was not showed in the rest 6 lesions.The remained one lesion showed in and fast out pattern on CT dynamic enhanced scan.Capsular retraction of hepatic parenchyma could be found in 4 cases,and mild biliary duct dilatation in 2 cases.Of the 6 cases undertook MRI,6 lesions were found.5 of them showed irregular low signal intensities on T2WI,and enhancement could be found on dynamic T1WI.The other one lesion demonstrated marked enhancement on arterial phase,but isointensity on venous and delayed phase.Histologically,all lesions were comprised of glandular or bile ductuloid tumor cells with dense fibrosis and connective tissue under microscope.Immunohistochemically,all lesions were positive for CK7.Conclusion:CT and MRI manifestations of peripheral nodular cholangiocarcinoma varied,due to the various proportions and distribution of the components with the lesion.Characteristic dynamic enhancement of the lesion could be assessed.