Contribution of the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI to Dynamic MRI in the detection of hypovascular small (≤2 cm) HCC in cirrhosis

Abstract

To prospectively assess the additional value of the hepatobiliary (HB) phase of Gd-EOB-DTPA-MRI in identifying and characterising small (≤ 2 cm) hepatocellular carcinomas (HCCs) undetermined in dynamic phases alone because of their atypical features, according to the AASLD criteria. 127 cirrhotic patients were evaluated with Gd-EOB-DTPA-MRI in two sets: unenhanced and dynamic phases; unenhanced, dynamic and HB phases. Sixty-two out of 215 nodules (29%) were atypical in 42 patients (33%). 62 atypical nodules were reported at histology: high-grade dysplastic nodules (HGDN)/early HCC (n = 20), low-grade DN (LGDN) (n = 21), regenerative nodules (n = 17) and nodular regenerative hyperplasia (n = 4). The sensitivity, specificity, accuracy, positive and negative predictive value (PPV, NPV) were increased by the addition of the HB phase: 88.4-99.4%, 88-95%, 88-98.5%, 97-99%, and 65-97.5%, respectively. Twenty atypical nodules were malignant (32%), 19 of which were characterised only during the HB phase. The HB phase is 11% more sensitive in the classification of HGDN/early HCC than dynamic MRI, with an added value of 32.5% in the NPV. The high incidence (33%) of atypical nodules and their frequent malignancy (32%) suggest the widespread employment of Gd-EOB-DTPA-MRI in the follow-up of small nodules (≤ 2 cm) in cirrhosis.