Usefulness of gadobenate dimeglumine-enhanced hepatobiliary phase MR imaging on predicting histological grade of hepatocellular carcinoma

Abstract

Purpose : To assess the usefulness of gadobenate dimeglumine-enhanced hepatobiliary phase MR imaging for evaluation of histological characteristics of hepatocellular carcinoma (HCC).Materials and Methods : 57 HCCs histopathologically proved by surgery in 51 patients were retrospectively evaluated. All patients underwent gadobenate dimeglumine-enhanced MR imaging prior to surgery. The signal-to-noise ratio (SNR) of lesion and liver, and the liver-to-lesion contrast-to-noise ratio (CNR) for both pre- and postcontrast hepatobiliary phase were measured and contrast enhancement ratio (CER) of lesion and liver were calculated to correlate with three groups stratified by histological grades (Edmondson-Steiner classification) of the lesions. The differences between means of each group were statistically analyzed with one-way analysis of variance test. Results : The liver-to-lesion CNRs of well-differentiated HCCs (n=9) on pre- (-0.8±13.2) and postcontrast hepatobiliary phase images (13.2±30.4) were significantly lower (P<0.05) compared to those of moderately (14.2±9.4 and 39.1±15.4 on pre- and postcontrast, respectively) (n=37) and poorly differentiated HCCs (18.6±11.3 and 39.3±27.9) (n=11), respectively. There were no significant difference for CERs between three histological tumor grades. Conclusion : Gadobenate dimeglumine-enhanced hepatobiliary phase MR imaging can help predict the histological grades of hepatocellular carcinomas preoperatively, especially differentiating well- from moderately and poorly differentiated HCCs.