Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging predicts the histological grade of hepatocellular carcinoma only in patients with Child-Pugh class A cirrhosis

Abstract

The aim of this study was to investigate the role of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) in predicting the histological grade of hepatocellular carcinoma (HCC) according to the hepatic function. Eighty-one consecutive patients with 122 histologically proven HCCs who underwent Gd-EOB-DTPA-enhanced MRI before resection (45 HCCs in 42 patients) or transplantation (77 HCCs in 39 patients) were analyzed retrospectively. We calculated the relative enhancement ratios (RER), which is the ratio of the relative intensity of a tumor versus the surrounding parenchyma on hepatobiliary phase images to the relative intensity on unenhanced MRI scans. We then analyzed the correlation between the RER and the tumor differentiation grade in patients with various degrees of hepatic function. The degree of tumor enhancement, which included the precontrast relative intensity ratio (RIR), the postcontrast RIR, and the RER, for well-differentiated (WD) HCCs was significantly higher than the degree of tumor enhancement for moderately differentiated and poorly differentiated (PD) HCCs (P = 0.001 and P = 0.001, respectively, for precontrast RIRs; P < 0.001 and P < 0.001, respectively, for postcontrast RIRs; and P = 0.01 and P = 0.001, respectively, for RERs). In a subgroup analysis based on liver function, the correlation between the histological grade and the enhancement ratio was demonstrated only in the group of patients with Child-Pugh class A cirrhosis. The accuracy of postcontrast RIRs for predicting WD and PD HCCs was favorable; the areas under the receiver operating characteristic curves were 0.896 [95% confidence interval (CI) = 0.817-0.974] and 0.769 (95% CI = 0.658-0.879), respectively. In conclusion, the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI may help to predict the differentiation of HCCs, especially in HCC patients with Child-Pugh class A cirrhosis before liver transplantation or resection.