MRIs, pacemakers don't mix
ORLANDO, Fla. - Cristina McShane is 25 and an exceptionally fit long-distance runner. But a year ago, a rare heart condition left her hospitalized and needing a pacemaker.
Ms. McShane, an Orlando physician's assistant at a cardiology practice, knew that she faced a dilemma: If she didn't get the pacemaker, the random pauses in her heartbeat would lead to continued blackouts, leaving her unable to drive and severely limiting the quality of her life. Getting the device, though, would make it dangerous for her to get an MRI, or magnetic resonance imaging, the most important tool for diagnosing certain soft-tissue problems, such as brain tumors.
In fact, most doctors wouldn't allow her to get an MRI.
"I was upset," Ms. McShane said. "I was only 24, and looking to the future and what I might need medically, I knew I might need an MRI. But I didn't have a lot of choice. I couldn't keep passing out."
Ms. McShane's youth made her case unusual, but millions of Americans already have implanted medical devices that make getting an MRI a problem.
Although fatal complications are rare, the threat is growing as more people get defibrillators, pacemakers and other implants and the use of MRIs increases, experts say. More than 60 million MRIs are performed in the U.S. each year to diagnose cancer, Alzheimer's disease, heart and artery conditions, and muscle, bone and back pain. Sometimes there are good alternatives to the scan, sometimes not.
And although most physicians are aware of the issue, a surprising number of patients and caregivers aren't. A survey of seniors by the National Council on Aging released this week found that nearly a third of adults 65 and older and more than half of their caregivers reported being uninformed about the problem.
"People are just not having the dialogue with their doctors that they need to," said Stuart Spector, senior vice president for the National Council on Aging. "I was aware of the problem because my father ... had an implantable device for Parkinson's. So I uncovered it speaking with his doctors."
The danger potentially applies to anyone with metal in his or her body because the MRI employs a powerful magnet. It can superheat the metal, burning heart tissue where the leads of a pacemaker are attached. Or it can disrupt the device's signal, causing the heart to go into a life-threatening arrhythmia.
Dr. David Bello, director of cardiovascular imaging at Orlando Health, said most orthopedic implants - typically, the pins and screws that hold together broken bones - are not a problem because they don't attach to soft tissue and they're not apt to come loose within the body.
Other devices that may cause problems range from insulin pumps and stents to cochlear implants for the deaf and neurostimulators used for depression or seizures. Even orthodontic braces are a problem, Dr. Bello said, though because they are used most often in children and could be removed if necessary, they're not as great a risk as an implant.
Imaging centers and hospitals post a list of MRI-incompatible devices for technologists. And patients with the devices are supposed to carry a card advising medical personnel of the situation. But because the diagnostic tool has become so popular, 98 percent of doctors in the NCOA survey said more education is needed.