Macrocyclic contrast agents for magnetic resonance imaging of chronic myocardial infarction: intraindividual comparison of gadobutrol and gadoterate meglumine

Objectives

To compare 0.15?mmol/kg gadobutrol for late gadolinium enhancement (LGE) imaging of chronic myocardial infarction with a relaxivity-adjusted dose of gadoterate meglumine (Gd-DOTA).

Methods

Seventeen patients with suspected chronic myocardial infarction underwent LGE imaging at 1.5 T, acquiring an inversion-recovery-prepared gradient echo sequence 15?min after contrast agent administration. Each patient underwent LGE imaging twice, once after administration of 0.15?mmol/kg gadobutrol (r1?=?5.2?l?mmol^-1?s^-1) and after 0.22?mmol/kg Gd-DOTA (r1?=?3.6?l?mmol^-1?s^-1). Two readers independently determined infarct size and contrast-to-noise ratios of infarcted myocardium to remote myocardium (CNR_remote) and to the left ventricular lumen (CNR_lumen).

Results

LGE was present in 14 patients. Infarct sizes determined after administration of gadobutrol [23.4?ml; 95?% CI (14.4; 32.5)] and Gd-DOTA [22.1?ml; 95?% CI (13.0; 31.1)] were not statistically different (P?=?0.22). The CNR_remote of LGE in infarcted myocardium on gadobutrol- and Gd-DOTA-enhanced images was 44.1 [95?% CI (31.0; 57.1)] and 45.2 [95?% CI (32.2; 58.3)], respectively (P?=?0.73). CNR_lumen was significantly higher on gadobutrol-enhanced LGE images [12.7; 95?% CI (2.5; 23.0) versus 6.8; 95?% CI (-3.5; 17.0); P?=?0.02].

Conclusion

At relaxivity-adjusted doses, gadobutrol and Gd-DOTA yielded similar infarct sizes with superior contrast between infarcted myocardium and left ventricular lumen on gadobutrol-enhanced images.

Key points

? Contrast-enhanced magnetic resonance imaging is increasingly used to assess the myocardium ? Macrocyclic Gd-based contrast agents are considered to be safer than linear agents ? Myocardial infarction MRI can be performed using either gadobutrol or gadoterate meglumine ? Contrast between infarcted myocardium and the left ventricular lumen was greater using gadobutrol ? The minimum macrocyclic dose needed for reliable LGE imaging requires further evaluation