Enhancement Pattern of Focal Hepatic Tumors with Gadobenate Dimeglumine-Enhanced Delayed MR Imaging

ABSTRACT

PURPOSE: To investigate the enhancement pattern occurring at delayed gadobenate dimeglumine (Gd-BOPTA) MR imaging, as used to characterize focal hepatic tumors. MATERIALS AND METHODS: Forty patients with 64 focal hepatic tumors (32 hepatocellular carcinomas [HCC], 15 hemangiomas, 14 metastasis and 3 cholangiocarcinomas) underwent MR imaging before and 60 minutes after the intravenous administration of 0.1 ml/kg Gd-BOPTA. For all MR studies, a 1.5-T MR system was used, and T1-weighted in-phase gradient echo (GRE) imaging was porformed. The quantitative assessment of early and delayed images included determination of the signal-to-noise ratio (SNR), tumor-to-liver contrast-to-noise ratio (CNR), and degree of enhancement (DE). Two experienced radiologists evaluated lesion conspicuity and the pattern of contrast enhancement (CE), reaching their conclusions by consensus. RESULTS: At delayed imaging, SNR and CNR showed significant increases (p>0.05), and the DE of all lesions had also increased. Lesion conspicuity, however, was not significantly different between (p>0.05). The most common enhancement patterns seen at delayed imaging were inhomogeneous hypointense in HCCs, homogeneous iso- or hyperintense in hemangiomas, and target-like in metastases. CONCLUSION: At delayed imaging with Gd-BOPTA, tumors of both hepatocytic and non-hepatocytic origin showed enhancement, and in the characterization of focal hepatic lesions, observed differences in enhancement are thus of limited usefulness. However, the observed homogeneous iso- or hyperinteuse enhancement of hemangiomas, and the target-like enhancement of metastases, may help differentiate then from other tumors.