The Food and Drug Administration (FDA) said Monday in a safety alert that it is investigating the risk of gadolinium being retained in patients who undergo MRI with certain gadolinium-based contrast agents (GBCAs).

“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 safety alert said. “It is unknown whether these gadolinium deposits are harmful or can lead to adverse health effects.”

Concerns about gadolinium retention have been growing over the last year, with multiple studies on the topic appearing in Radiology and other publications raising concern about lingering deposits of the heavy metal. Early evidence suggests that GBCAs of linear molecular structure, as opposed to macrocyclic agents, may carry more of a risk for releasing free gadolinium in the body. 

Emanuel Kanal, MD, a recognized expert on MRI safety, spoke at length with HealthImaging.com earlier this year about the need for more accountability and oversight by radiologists in regards to using GBCAs.

In its alert, the FDA stressed that it is not requiring any labeling changes at this time due to a lack of concrete information. However, physicians are asked to limit their use of GBCAs when possible.

“To reduce the potential for gadolinium accumulation, healthcare professionals should consider limiting GBCA use to clinical circumstances in which the additional information provided by the contrast is necessary,” the alert said. “Healthcare professionals are also urged to reassess the necessity of repetitive GBCA MRIs in established treatment protocols.”

If anyone wishes to report “adverse events or side effects” related to gadolinium and GBCAs, they can fill out the online form or call 1-800-332-1088, according to the alert.