Gadolinium-based contrast agents (GABAs) were first approved by the FDA in 1998. The American College of Radiology estimates that over the past two decades GABAs have been used on 300 million people around the globe in order to assist doctors in interpreting MRIs. According to a recent article in Radiology, as many as 27 million Americans undergo an MRI with the use of a contrast agent every year.
Chances are good that anyone who has had an MRI “with contrast” has had gadolinium exposure. Normally, up to 98% of that gadolinium leaves the body through urination. However, those with impaired kidney function run the risk of developing a condition known as nephrogenic systemic fibrosis, a disorder characterized by hardening of the skin surface, swelling, itching, and bone pain. It can also compromise organ function and result in muscular weakness. For the past twelve years, physicians have made it a point to test patients for kidney impairment before ordering an MRI.
While most gadolinium may be excreted through the kidneys, small deposits can wind up in the brain and remain there for many years. This has raised serious questions about the safety of GABAs. In May 2015, an FDA alert was issued and there was a call for more research into the possible dangers.
In December 2017, the FDA began requiring new warnings for GBCAs, urging caution – particularly with pregnant women, patients with poor kidney function, and those who have had MRIs with a GABA previously. The European Medicines Agency went a step further – although they admitted there was no irrefutable scientific evidence of injury due to gadolinium retention, they suspended the use of GABAs in EU countries with very few exceptions.
The recent ongoing lawsuit filed by film actor Chuck Norris and his wife Gena have brought the issues of gadolinium to public attention. Mrs. Norris currently suffers from several symptoms, which include chronic pain, breathing difficulties, kidney damage, and cognitive impairment, which all are consistent with heavy metal poisoning. The couple claims these conditions are due to Mrs. Norris’s exposure to GBCAs in 2012.
Although the FDA has issued warnings, its official position is that “gadolinium retention has not been directly linked to adverse health effects in patients with normal kidney function, and…has concluded that the benefit of all approved GBCAs continues to outweigh any potential risks.”
If your physician recommends an MRI and you have concerns, there are some questions you should ask. First of all, find out if the MRI will be performed with or without the use of a contrast agent. Generally, this will depend on what is being examined. If it is a joint, chances are that a contrast agent will not be necessary. On the other hand, an examination of the heart or other internal organ usually requires the use of a contrast agent.
You should also ask if there are alternatives to an MRI, or if a different scan will provide the necessary images or information. Studies carried out so far indicate that patients who exhibit symptoms of gadolinium poisoning have undergone MRIs at least four times, so if you have had one recently – or expect to undergo additional scans – it is a good idea to ask this question.
If there is no avoiding it, find out what kind of GBCA will be used. Two forms are currently used: one is known as “linear,” and the other is “macrolytic.” The latter form is “caged” within a molecule that is more easily eliminated from the body, whereas the “linear” type is made up of “free” gadolinium and is more likely to result in accumulation in the brain.