On call: MRIs and coronary stents
MRIs and coronary stents
Q. When I had an MRI of my knee after a skiing injury last fall, I was told the test was dangerous for people who have metal devices in their bodies. Since then, I developed angina and my cardiologist put in a metal stent. I'm doing fine, but if I need an MRI in the future, will I be able to get one?
A. It is true that MRIs are dangerous in patients with certain artificial joints, cardiac pacemakers and defibrillators, and other implanted metal devices. Even a tiny metal fragment in the eye can be hazardous, since the energy from an MRI can cause the metal to heat up, possibly damaging sensitive tissues.
Fortunately, coronary artery stents are different. Doctors in England evaluated 49 patients with stents who had MRIs within three days of their angioplasties, when stents are most vulnerable. Most patients had more than one stent; the average was 2.2. There were no adverse consequences at the time of the MRIs, and when the patients were evaluated after nine months, 96% of them had excellent stent function.