The Food and Drug Administration (FDA) is investigating the risk of brain deposits following repeated use of gadolinium-based contrast agents (GBCAs) for magnetic resonance imaging (MRI). Recent publications in the medical literature have reported that deposits of GBCAs remain in the brains of some patients who undergo four or more contrast MRI scans, long after the last administration.
The FDA says it is not known whether gadolinium deposits are harmful or can lead to adverse health effects.
The FDA is working with the research community and industry to understand the mechanism of gadolinium retention and to determine if there are any potential adverse health effects.
The National Center for Toxicological Research (NCTR) of the FDA will be involved in the study of this possible safety risk. Based on the information available at this time, the FDA is not requiring manufacturers to make changes to the labels of GBCA products.
Contrast agents are used to increase the visibility of internal body structures in MRI scans. MRI contrast agents may be administered by injection or orally. Oral administration is well suited to gastrointestinal tract (GI) scans, while intravascular administration proves more useful for most other scans. GBCAs are mostly eliminated from the body through the kidneys, but trace amounts of gadolinium may stay in the body long-term, according to the FDA.
Researchers advise that GBCAs should not be given to any individual with chronic kidney disease
Recent studies conducted in people and animals have confirmed that gadolinium can remain in the brain, even in individuals with normal kidney function. Researchers advise that GBCAs should not be given to any individual with chronic kidney disease. Available information has not identified any adverse health effects, the FDA says.
To reduce the potential for gadolinium accumulation, the FDA suggests that health care professional should consider limiting GBCA use to circumstances in which the additional information provided by the contrast is necessary.
Health care professionals are also urged to reassess the necessity of repeat GBCA MRIs. Patients, parents, and caregivers should talk to their health care professionals if they have any questions about the use of GBCAs with MRIs. This issue affects only GBCAs; it does not apply to other types of contrast agents used for other imaging procedures, such as those that are iodine-based or radioisotopes.
The FDA encourages health care professionals and patients to report adverse events or side effects related to the use of these products to the FDA’s MedWatch Safety Information and Adverse Event Reporting Program: www.fda.gov/MedWatch/report.