Correlation between dynamic contrast-enhanced CT and MRI features of intrahepatic mass-forming cholangiocarcinoma and pathologic differentiation

Abstract

Objective To investigate the correlation between dynamic contrast-enhanced CT and MRI image findings of intrahepatic mass-forming cholangiocarcinoma(IMCC) and pathologic differentiation. Methods The CT and (or) MRI features of ninety-five patients with IMCC proved by pathologic examination were retrospectively reviewed. Sixty-five patients underwent multiphasic dynamic contrast-enhanced CT scan, twenty-nine underwent multiphasic dynamic contrast-enhanced MRI scan and ten patients underwent multiphasic dynamic contrast-enhanced CT and MRI examination simultaneously. According to the case history and laboratory examination, patients were divided into groups: with chronic hepatitis and without chronic hepatitis and according to the maximum diameter of the tumor, they were divided into 6 cm groups. The imaging features of tumor enhancement were reviewed among groups. The pathologic results and imaging features were compared and patients were divided into well differentiated, moderately differentiated, and poorly differentiated groups. Analyzed by Chi-square test, the difference of tumor enhancement between groups were analyzed. Results The patterns of multiphasic dynamic contrast-enhanced CT and MRI in IMCC patients had five types: type1∶60 cases, peripheral rim and (or) separating enhancement during artery phase, followed by centripetal enhancement progressively and(or) separating enhancement in the equilibrium phase; type 2∶11 cases, peripheral rim enhancement in the artery phase and hypointensity (hypoattenuating) during equilibrium phase with central nodular enhancement; type 3∶15 cases, no enhancement in the arterial phase and internal heterogeneous enhancement during equilibrium phase; type 4∶6 cases, heterogeneous enhancement in the early phase and wash-out during equilibrium phase; type 5∶3 cases, no enhancement throughout dynamic enhancement.The results showed that in hepatitis group type1 to 5 had 31, 7, 12, 5 and 1 cases and without hepatitis group had 29, 4, 3, 1 and 2 cases. There was no statistical significance between groups(χ2=3.567,P=0.059). The maximum diameter 6 cm group(27 cases) had 24, 1, 2, 0 and 0 cases. There was significant difference in groups(χ2=19.582,P<0.01).Pathological well differentiated and moderately differentiated groups(40 cases) had 24, 7,6, 2 and 1 cases presented enhancement type 1 to 5 and poorly differentiated group(55 cases) had 36, 4, 9, 3 and 3 cases. There was no statistical difference in three differentiated groups(χ2=0.296,P=0.586). Conclusions CT and MRI enhancement patterns of IMCC are presented with diversity. The imaging features are associated with focus size and had no relationship with pathological differentiated degree. Key words: Liver neoplasms; Bile duct neoplasms; Tomography, X-ray computed; Magnetic resonance imaging