Multiphase CT scans findings for AI training in the differentiation of hepatocellular carcinoma and intrahepatic cholangiocarcinoma based on interobserver agreement of expert abdominal radiologist.

Computed tomography (CT) is the imaging modality used to evaluate liver nodule and differentiate hepatocellular carcinoma (HCC) from intrahepatic cholangiocarcinoma (ICC). The purpose of this study was to find out potential CT features in the differentiation of hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Patients with radiological and pathologically confirmed diagnosis of HCC and ICC between January 2013 and December 2015 were included. Two board certified diagnostic radiologists independently reviewed multiphase CT images. Most of HCC showed arterial hyperenhancement at 95.8%. Arterial enhancement in ICC was less often at 15.4% to 26.9%. Two readers showed a moderate agreement of cirrhosis appearance in both HCC and ICC. Cirrhosis appeared in HCC group more frequently than ICC group. Lymph node enlargement was more common seen in ICC than HCC and agreement between readers was almost perfect. Portal vein invasion in HCC was seen 14.6 % by both readers with a substantial agreement. We believed cirrhosis appearance and lymph node enlargement could be remarkable imaging feature in differentiated HCC and CCA.