MR Angiography at 3 T of Peripheral Arterial Disease: A Randomized Prospective Comparison of Gadoterate Meglumine and Gadobutrol

OBJECTIVE. This large-scale randomized study aimed to show the noninferiority in terms of diagnostic performance of gadoterate meglumine-enhanced versus gadobutrol-enhanced 3-T MR angiography (MRA) using digital subtraction angiography (DSA) as the reference standard in patients with peripheral arterial occlusive disease (PAOD). SUBJECTS AND METHODS. In this prospective international randomized double-blind phase IV trial, 189 patients were enrolled. Of them, 156 could be included in the per-protocol population for on-site assessments and 154 for off-site readings. Subjects underwent peripheral MRA, after injection of 0.1 mmol/kg of either gadoterate meglumine or gadobutrol, and DSA within 30 days. The diagnostic accuracy was evaluated and compared using a noninferiority analysis. Secondary endpoints included sensitivity, specificity, diagnostic confidence, contrast-to-noise ratio, and signal-to-noise ratio evaluations. RESULTS. The percentage agreement between MRA and DSA for stenosis detection was similar for on-site readings for both groups (mean +/- SD, 80.6% +/- 16.1% with gadoterate meglumine vs 77.1% +/- 19.6% with gadobutrol; 3.5% difference), and the same was true for off-site readings (73.9% +/- 16.9% with gadoterate meglumine vs 75.1% +/- 13.8% with gadobutrol; 1.1% difference). The noninferiority of gadoterate meglumine to gadobutrol was shown for both on-and off-site readings. Sensitivity in detecting significant stenosis (> 50%) was 72.3% for gadoterate meglumine versus 70.6% for gadobutrol, whereas specificity (92.6% vs 92.3%), diagnostic confidence (87.0% vs 86.0%), signal-to-noise ratio (165.5 vs 161.0), and contrast-to-noise ratio (159.5 vs 155.3) did not differ statistically significantly between the two groups. CONCLUSION. Gadoterate meglumine was found to be not inferior to gadobutrol in terms of diagnostic performance in patients with PAOD undergoing 3-T contrast-enhanced MRA. No statistically significant differences were detected between the two MRA groups.