The U.S. Food and Drug Administration (FDA) is investigating the potential for brain deposits caused by repeated use of gadolinium-based contrast agents (GBCAs) for magnetic resonance imaging (MRI). According to recent publications in medical literature, there have been reports that GBCAs remain in the brains of some patients who undergo four or more MRIs, long after the patients have the scans.
The FDA, including its National Center for Toxicological Research (NCTR), will study the safety risk, as it is not known whether these gadolinium deposits are harmful or may lead to adverse health effects. The agency said it will not require manufacturers to make changes to the labels of GBCA products at this time.
GBCAs are primarily eliminated from the body through the kidneys, but trace amounts may stay in the body for long periods of time. Recent studies conducted in humans and animals have confirmed that gadolinium can remain in the brain, even in patients with healthy kidneys.
The FDA is instructing healthcare professionals to limit the potential for gadolinium accumulation by limiting GBCA use to clinical circumstances in which the additional information provided by the contrast is necessary. The agency is also urging healthcare workers to reassess the necessity of repetitive GBCA MRIs in established treatment protocols.
Patients and caregivers should discuss any questions concerning the use of GBCAs with MRIs with their healthcare professionals, the agency said. This issue is limited to GBCAs and does not apply to other types of scanning agents used for other imaging tests, such as those that utilize isotope-based radioisotopes.