Ferumoxytol-enhanced cardiovascular magnetic resonance imaging: applications and technical advances.

Magnetic resonance imaging with gadolinium chelates has transformed the diagnostic practice of cardiovascular medicine. From anatomic and functional cardiac imaging to myocardial tissue composition, vascular imaging, and blood flow measurement, the clinical benefits of contrast-enhanced cardiovascular magnetic resonance (CMR) are well established. Since their introduction over 40 years ago, gadolinium chelates have had an excellent safety track record; however, concerns related to gadolinium retention have prompted in-depth consideration of potential risks and benefits in some patient groups. Recently, ferumoxytol has emerged as an off-label, versatile blood-pool contrast agent for CMR. Endowed with high r1 and r2 relaxivities, ferumoxytol is a clinically available intravenous iron supplement that was initially designed as a diagnostic agent and in 2025, was approved by the U.S. Food and Drug Administration for brain imaging. Because iron is vital for many biological processes, ferumoxytol spans both diagnostic and therapeutic dimensions. In this review, we summarize the attributes of ferumoxytol, highlight promising research directions, and illustrate several growing ferumoxytol-enhanced CMR applications. We conclude with a discussion of safety.