The clinical value of spectral CT iodine-based material decomposition imaging in differentiating intrahepatic cholangiocarcinoma from atypical hepatocellular carcinoma

Objective: To explore the clinical value of spectral CT Iodine-based material decomposition imaging in differentiating intrahepatic cholangiocarcinoma (ICC) from atypical hepatocellular carcinoma (AHCC). Methods: Retrospectively analyzed 52 patients of our hospital during April 2013-February 2014 who underwent tri-phase enhanced spectral CT imaging including arterial phase, portal venous phase and equilibrium phase. Primary hepatocellular carcinoma (ICC patients 24 cases, AHCC patients 28 cases)was pathologically confirmed in each case. The Iodine concentrations of ICC, AHCC, and normal hepatic tissue in tri-phase were measured. The iodine concentration differences between equilibrium phase and arterial phase (EAD), lesion and normal hepatic tissue iodine concentration difference during equilibrium phase (LNDE) were calculated. The group differences of ICC and AHCC were evaluated by two samples t test and receiver operating characteristic curve (ROC) analysis. Results: During arterial phase, portal venous phase, and equilibrium phase, the mean iodine concentrations of ICC were significantly higher than those of AHCC (P < 0.01). The EAD and LNDE of ICC were significantly higher than those of AHCC (P < 0.01). ROC analysis showed that the sensitivity and specificity of the iodine concentration during equilibrium phase, EAD and LNDE in differentiating between ICC and AHCC were 95.8% and 92.9%, 62.5% and 89.2%, 95.8% and 82.1%, respectively. Conclusion: Spectral CT iodine-based material decomposition image is a suitable tool to quantitatively evaluate contrast enhancement characteristics of ICC, the iodine concentration measurement during equilibrium phase performs best in differentiating AHCC from ICC. (authors)