Most patients getting an MRI don’t know to ask a critical question: Will the MRI use gadolinium or not?
Magnetic resonance imaging with a gadolinium-based contrast agent, called a GBCA, leaves metal deposits in the body’s organs and tissues including the brain, research shows. Scientists are exploring whether the deposits harm patients.
Gadolinium is a metal dye injected into the veins to help radiologists better read an MRI scan. The dye is used, experts estimate, in as many as half of the millions of MRIs performed annually in the U.S., generally for scans that are looking for tumors, severe inflammation or blood vessels. Doctors say the dye makes it possible to detect and diagnose more detail. MRIs to look at bone and joint issues don’t need a contrast agent for doctors to make a diagnosis.
Some patients with healthy kidneys are reporting getting sick from the dye and are pressing for more research and warnings to the public. Doctors have for years cautioned patients with serious kidney problems about getting MRI’s that use gadolinium because their kidneys can’t always fully flush out the metal toxins.
Earlier this month an advisory committee to the U.S. Food and Drug Administration voted 13 to 1 in favor of adding a warning on labels that gadolinium can be retained in some organs, including the brain, even in patients with healthy kidneys. Certain types of agents, called linear GBCAs, have a greater retention than others, such as macrocyclic GBCAs, the committee warned. It also voted to request that manufacturers of GBCAs perform more studies to see if there is a need for additional regulatory actions, such as restricting their use in pregnant women and children.
“People understand the incredible value that MR with contrast has brought to medicine,” says
a member of the committee and professor of radiology and pediatrics at the University of Kentucky in Lexington, speaking as an individual and not on behalf of the committee. “We need to image gently.”
senior associate consultant of neuroradiology at the Mayo Clinic in Rochester, Minn., says studies he and others have done using animals and postmortem human tissue have shown that residual gadolinium is retained in tissues and organs. “We’re trying to understand to what extent it’s happening in the tissues of the body and also the clinical significance, if any,” says Dr. McDonald who was at the FDA committee hearing after several manufacturers asked him to attend.
, one of the manufacturers of GBCAs, paid for his travel expenses.
“The big question is whether or not these deposits are biologically active,” he says. “So far we haven’t been able to see any evidence of tissue injury.”
A spokeswoman for GE Healthcare Life Sciences, one of several manufacturers of GBCAs, says GE strongly supports the FDA vote and “agree that further research is needed in this area.”
“It’s a critical tool for the detection and diagnosis of many diseases,” says
a professor of radiology at the University of Wisconsin, Madison who spoke at the FDA hearing representing the International Society for Magnetic Resonance in Medicine and the Society of Computed Body Tomography and Magnetic Resonance.
The term “gadolinium deposition disease” was coined by
until recently director of MRI Services and a professor of radiology at UNC Hospitals in Chapel Hill, N.C., in a paper published last year in the American Journal of Roentgenology. He estimates that about one in 1,000 people with gadolinium deposits in their body will get sick from it. “We have to figure out who these people are,” he says. “They appear to be people who have a genetic problem with handling heavy metals.”
was among the patients to testify at the FDA hearing. Ms. Combs was in the insurance industry for 30 years before going on disability last year due to complications such as muscle weakness that she believes stem from gadolinium deposition from an MRI done in 2006.
“I was in the absolute prime of health,” says the 55-year-old, who lives in a suburb near Cleveland. “I was out hiking and slipped and fell and hit the back of my neck on a log.”
A doctor recommended an MRI of her brain. She says she immediately felt burning and strokelike symptoms after the MRI and could barely walk by the time she got home. She was rushed back to the emergency room with seizures and discharged after doctors couldn’t find anything wrong with her. “I have never been the same since,” she says. Symptoms have included burning sensations in her body, sunburn-like rashes, blistering, tremors and difficulties walking, as well as cognitive declines.
The FDA advisory committee’s action, she says, is not enough. “A patient isn’t going to see the label,” she says.
a staff physician at the South Texas Veterans Health Care System in San Antonio and a nephrologist, says his laboratory studies have found that human cells exposed to gadolinium show signs of fibrosis, or scarring. He says the symptoms that patients with healthy kidneys have complained about are similar to the ones exhibited by kidney patients who develop nephrogenic systemic fibrosis (NSF) from gadolinium exposure, a rare disease that causes severe pain and scarring all over the body and in the internal organs.
Dr. Wagner is now using animal models to identify the mechanism that results in patient symptoms. The goal is to develop a screening tool to identify the patients who are at a higher risk of having a bad reaction to the gadolinium. He ultimately hopes to invent a way to lessen their risk of a bad reaction.
Write to Sumathi Reddy at email@example.com