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MRIs pose risk for patients with pacemakers, other implanted devices: Advocates hope to raise awareness of effects of MRIs on metal implants.

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. 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.

McShane's youth made her case unusual, but millions of Americans already have implanted medical devices that make getting an MRI a problem -- prompting advocates for the elderly to launch an awareness campaign Saturday in Orlando.

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.

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, and it burns 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 likely to come loose within the body. But even those are worth mentioning should have an MRI.

"The biggest risk is to people with pacemakers and defibrillators because they attach to the heart and because a large number of people have those devices now," he said. "One of our patients has a brain tumor and he has a pacemaker, and we had to allow him to have an MRI with a crash cart standing by in case he went into cardiac arrest."

Doing so leaves the doctor with a huge risk of being sued -- a risk most doctors wouldn't take. But because Bello has done extensive research on the issue, including developing an MRI-compatible pacemaker that is awaiting approval by federal regulators, he ends up dealing with similar cases about once a month. McShane, who works for Bello's practice, was also one of his patients.

"I requested to the FDA that we use one of the experimental, MRI-compatible pacemakers in her case -- because she is so young," he said. "But ultimately they declined."

Other devices that may cause problems range from insulin pumps and stents to cochlear implants for the deaf and neuro-stimulators used for depression or seizures. Even orthodontic braces are a problem, 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 in their wallet 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.

The National Council on Aging will kick off a cross-country awareness campaign in Orlando on Saturday with a three-hour event focused on MRIs and implanted medical devices.

Source: Orlando Health

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