MRI and Implant Safety at Low-Field and Ultralow-Field Strengths

Despite its unequivocal value in radiological diagnosis, access to conventional high-field MRI systems remains extremely uneven across the world. Access is particularly limited in underfunded and remote settings, due to the high cost and infrastructure requirements of MRI systems. Low-field MRI offers a range of benefits including affordability, portability, suitability for use in intensive care units, and for point-of-care imaging. Different low-field configurations enhance flexibility in various clinical scenarios, including imaging claustrophobic or obese subjects, accommodating different body postures, extremity-focused investigations, and neonatal imaging. Moreover, lower field strengths offer important safety benefits. However, the overarching assumption that lower fields are safe without exception may foster a false sense of security, potentially leading to hazardous situations. On behalf of the International Society for Magnetic Resonance in Medicine, this paper provides a comprehensive review of important safety considerations for low-field MRI, aiming to inform users and stakeholders of both its benefits and limitations, and to empower them toward its safe use. These recommendations are likely to evolve as new evidence becomes available. EVIDENCE LEVEL: 5. TECHNICAL EFFICACY: Stage 5.