The Diagnosis of Intrahepatic Peripheral Cholangiocarcinoma by CT and MRI Correlated with Pathological Findings Study

Objective To study the characteristics of imaging features of intrahepatic peripheral cholangiocarcinoma(IHPCC) on the CT,MRI and correlate these features with histo pathologic findings.Methods Thirty-two patients with pathologically proven IHPCC were reviewed retrospectively.The twenty-nine patients were performed CT scanning and dynamic enhancement.MR imaging were obtained in five patients,and dynamic contrast-enhanced T1-weighted imaging was performed in 2 cases.Results The location of lesions was 24 lesions(75%) in lift lobe and 8 lesions(25%) in right lobe.According to pathological type,the imaging type of tumors were mass-type 18 cases,infiltrative-type 7 cases and intracavitary-type 4 cases.In three patients the tumors were not definable at any imaging phase.The shape of tumor was circular,lobulated,irregular.and margins were clouding.No contrast or rimelike contrast enhancement with mild or moderate were the most frequent enhancement pattern observed in early stage.On the delay scan imaging,the central of tumor was showed mottling,reticular or homogeneous hyperattenuating delayed contrast enhancement.The tumor was consisted of fibrous tissue,tumor cells and coagulative necrosis at the findings of histopathologic analysis.The content of these portion was difference in different positions of tumor.At the edge of tumor,the main components was living tumor cell that was the pathological base of early contrast enhancement.The delay contrast enhancement tended to be fibrosis,that mainly situated in the tumor central,because the contrast material entrance fibrosis was very slowly but stagnated in it for long time.Conclusions Dynamic contrast enhancement scan was very important techniques for the correctly diagnosis of IHPCC.It is a typical feature of IHPCC that hypodensity of hepatic lesion on precontrast scan imaging,peripheral enhancement in the early stage and tumor central delayed contrast enhancement on the dynamic contrast enhancement scan.