To investigate the enhancement pattern occurring at delayed gadobenate dimeglumine (Gd-BOPTA) MR imaging, as used to characterize focal hepatic tumors.

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.

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.

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.