The FDA is currently investigating whether remnants of gadolinium-based contrast agents (GBCAs) used in MRI can remain in the brains of patients long after administration.
The inquiry follows several published reports that reported deposits of GBCAs in the brains of patients who underwent four or more contrast MRI scans. It is not known whether the deposits are harmful or if they could lead to adverse effects on health.
The FDA, along with the National Center for Toxicological Research, is working with the research community and industry to better understand the mechanism behind gadolinium retention and determine any adverse effects. As of now, the FDA is not requesting that manufacturers make changes to the labels of GBCA products.
GBCAs are usually flushed from the body through the kidneys; however trace amounts of GBCAs may linger in the body for long periods after administration. In this case, researchers found deposits in the brain, even in those with normal kidney function. No adverse events were recorded in the published reports. The current inquiry only affects GBCAs and not other scanning agents, including iodine-based agents or radioisotopes.
Until further information is made available, the FDA is asking healthcare professionals to limit use of GBCA to circumstances where contrast information is clinically necessary, and to evaluate the need for repetitive GBCA MRIs based on treatment protocols.
In the event of adverse health effects related to the use of GBCAs, healthcare professionals and patients are encouraged to report these events to the FDA’s MedWatch Safety Information and Adverse Event Reporting Program.