RESUMEN
Objective To studying the MR findings and pathology of peripheral small intrahepatic cholangiocarcinoma and improving the understanding of peripheral small cholangiocarcinoma with no-bile duct dilatation. Methods A retrospective analysis of 12 patients with intrahepatic peripheral cholangiocarcinoma which were confirmed by surgery and pathology, all patients were examined by abdominal MRI without and with contrast. Correlation was made with gross pathology and surgical pathological specimen. Results On T1WI, there were 4 cases of complex low signal intensity and 8 cases of low signal intensity. On T2WI, there were 8 cases of high signal intensity and 4 cases of complex high signal intensity. Enhanced MRI showed: marked nidus enhancement on arterial phase in 1 case, and the pathological diagnosis was poorly differentiated adenocarcinoma. Inhomogeneous enhancement or annular enhancement were seen in 10 cases on arterial phase, 3 of these cases showed thin annular enhancement on arterial phase, low signalintensity on portal venous phase and isointensity on delayed phase. One case showed delayed enhancement. Thick circular enhancement correlated with pathological changes of survival of tumor cells, center areas correlated with fibrous connective tissue, and a small amount of necrotic tissue. Island-like enhancement or inhomogeneous enhancement were seen in 3 cases. Corresponding pathological changes consisted of tumor tissue and a small amount of fibrous connective tissue, as well as somenecrotic tissue. In 1 case, no enhancement was seen on all three phases and pathological changes showed cystic changes, hemorrhage, necrosis, with survival tumor cells seen between cyst and normal liver tissue. Conclusions MRI scanning of peripheral small cholangiocarcinoma lacked characteristic features, but dynamic contrast-enhanced MR had certain specific findings. Due to different pathology, the fibrous tissue, necrotic tissue and survival tumor tissue components were exhibited different imaging findings.