A new study raises questions about the link between gadolinium-based MRI contrast agents and toxic side effects reported by some users, who have been left with persistent headaches, pain and other complications.
In recent months, a number of MRI toxicity lawsuits have been filed against the manufacturers of gadolinium contrast agents, such as Magnevist, Gadavist and Omniscan.
The complaints allege that use of MRI dyes to enhance imaging tests have left users with a condition known as gadolinium deposition disease (GDD), which involves various symptoms, including reduced cognitive function, headaches, bone and joint pain, tendon and ligament pain, thickening of soft tissues and other problems. The condition is considered incurable and progressive, meaning that it worsens over time, raising concerns about the safety of gadolinium contrast agents.
In a new study presented at the annual meeting of the Radiological Society of North America (RSNA) on November 29, researchers from the Mayo Clinic raise questions about the potential toxicity of gadolinium contrast agents. The findings were announced in an RSNA press release and have not yet been published for peer review.
Researchers looked at more than 4,200 cognitively normal men and women between the ages of 50 and 90, found that gadolinium was not linked to any signs of cognitive decline, dementia, neuropsychological performance or movement problems. They also found no dose response relationship.
“Right now there is concern over the safety of gadolinium-based contrast agents, particularly relating to gadolinium retention in the brain and other tissues,” the study’s lead author, Dr. Robert J. McDonald, of the Mayo Clinic, said in the press release. “This study provides useful data that at the reasonable doses 95 percent of the population is likely to receive in their lifetime, there is no evidence at this point that gadolinium retention in the brain is associated with adverse clinical outcomes.”
In prior years, concerns emerged about the safety of MRI gadolinium contrast agents, after it was linked to a rare and life-threatening condition known as nephrogenic systemic fibrosis (NSF), which was found to occur among patients with impaired kidney function, causing their skin to thicken and harden, severely restricting movement.
Sometimes referred to as gadolinium associated systemic fibrosis, NSF is a painful disorder that has no known cure and often results in confinement to a wheelchair and then death.
In 2007, the FDA limited gadolinium contrast doses in most patients and contraindicated it for others, which limited the risk of NSF. In September 2010, the FDA went even further and banned the use of Bayer’s Magnevist on patients with kidney problems, due to the heightened risk of NSF.
The agency also required label changes for all gadolinium agents, warning healthcare professionals to screen patients before injecting gadolinium to identify those suffering from acute kidney injury or chronic, severe kidney disease.
However, the new lawsuits, the most high profile of which was filed by actor and martial artist Chuck Norris on behalf of his wife, indicate that the plaintiffs or family members who suffered gadolinium poisoning suffered no reduced kidney function, raising questions as to whether the gadolinium contrast agent side effects are limited to those with kidney problems.
Recently, there have also been growing concerns over signs of gadolinium build-up in the body. In September, the FDA’s Medical Imaging Drugs Advisory Committee voted to recommend the FDA require new MRI contrast agent warnings about the risk of gadolinium build up in the brain. However, in May the FDA concluded that gadolinium in the brain appeared to carry no threat of health effects.
The FDA is continuing to assess their safety, and its National Center for Toxicological Research is currently conducting a study on gadolinium brain retention in rats.