MRI Safety: Operational Issues and Contrast Agent Administration Precautions

The American College of Radiology (ACR) has developed a guidance document that addresses important MRI safety concerns. For instance, the ACR emphasizes the importance of creating 4 separate zones of increasingly limited access to prevent the entry of hazardous objects, including any metal object that is subject to attraction by a magnetic field, from entering the MRI operational suite. These precautions were spelled out as a result of reports of metallic objects being brought into the MRI suite and becoming deadly projectile objects when entering the magnetic field.3 The ACR guidance document also warns that patients should be properly evaluated to ensure that they have not received any implanted objects that could likewise be subject to the magnetic field, which could disrupt the study or cause considerable patient harm due to burns or other complications.3
The administration of an intravenous (IV) contrast agent is another important safety consideration in MRI studies. Individuals can potentially suffer from adverse reactions to gadolinium-based contrast agents (GBCA), and those who have experienced a reaction to another agent may also react to GBCA. The ACR recommends that those who have suffered from previous reactions can be treated with corticosteroids, and in some cases antihistamines, prior to the administration of the GBCA. Likewise, although the use of MRI is generally accepted as safe during pregnancy, the ACR recommends that studies with contrast agents should be avoided, if possible, during pregnancy.3

--> Although rare, cases of nephrogenic systemic fibrosis have been reported in individuals with previous kidney disease who had undergone MRI studies with gadodiamide, a GBCA. As a result, the US Food and Drug Administration (FDA) recommends that clinicians should refrain from conducting imaging studies requiring the administration of GBCA in patients with advanced kidney disease (glomerular filtration rate [GFR] <60 mL/min/m2).4 The ACR also recommends that patients with a history of renal disease (including solitary kidney, renal transplant, or renal tumor); age greater than 60 years; a history of hypertension; a history of diabetes; or a history of severe hepatic disease, liver transplant, or pending liver transplant, should receive an updated GFR assessment within 6 weeks of undergoing an imaging study requiring the administration of GBCA.5
Although these precautions should be strictly followed in administering GBCA, the contrast agents used in MRI studies, including cardiac MRI, are generally safe and do not pose excessive hazards to most patients.