Double-dose 1.0-M gadobutrol versus standard-dose 0.5-M gadopentetate dimeglumine in revealing small hypervascular hepatocellular carcinomas

The purpose of this study was to compare the diagnostic efficacy of double-dose 1.0-M gadobutrol with that of standard-dose 0.5-M gadopentetate dimeglumine for revealing small hypervascular hepatocellular carcinomas (HCCs). Twenty-three patients with 37 HCCs (mean size: 1.2 cm) that were diagnosed by histology (n = 13) or imaging findings (n = 10) underwent two separate 3D dynamic MRIs with 0.2 mmol/kg of gadobutrol and 0.1 mmol/kg of gadopentetate dimeglumine. Three observers interpreted both MRIs in terms of lesion detection using the alternative-free response receiver operating characteristic method and lesion-to-liver contrast using matched pairs analysis. The two MRIs were also compared quantitatively by measuring the signal-to-noise ratio (SNR) of the liver and lesion as well as the lesion-liver contrast-to-noise ratio (CNR). The SNR of the liver and lesion and lesion-liver CNR with gadobutrol were better than those with gadopentetate dimeglumine (p < 0.01). However, in terms of the diagnostic accuracy (mean Az for gadobutrol: 0.878, and mean Az for gadopentate dimeglumine: 0.873), the sensitivity (92.8%), positive predictive value (92.8% vs. 93.7%) and lesion-liver contrast, the two dynamic MRIs were equivalent. Gadobutrol showed a superior degree of enhancement for hypervascular HCC than did gadopentetate dimeglumine, but the diagnostic capabilities of the two agents for revealing HCCs were equivalent. (orig.)