It's something else for seniors and caregivers to remember: If someone has a pacemaker, newly released research indicates that an MRI might not be a safe procedure. With potentially one of every four people receiving an MRI also having an implanted pacemaker, this raises some serious concerns.

In a study released in late 2009, FDA researchers identified an MRI safety risk for anyone with a pacemaker. MRI systems expose patients to very strong magnetic fields, which can disturb electronic pulses generated by the pacemaker. According to the research, the magnetic field can also increase the temperature at the tip of the pacemaker lead within the heart, cause burning of heart tissue.

FDA researchers found that when exposed to the strong, "gradient" magnetic field, the pacemaker could deliver a drastically altered pulse and stimulate the heart inappropriately, which could have devastating consequences for the patient.

According to the National Council on Aging, after the age of 65, a person's chance of needing medical imaging doubles, and between 50% and 75% of patients with electronic implantable devices will likely need medical imaging over their device's lifetime.

The survey, made possible by a grant from Medtronic, found that nearly a third of patients and more than half of caregivers did not recall being informed that they or the person they care for might not be eligible for some forms of medical imaging at the time the device was implanted. The survey also found that three in 10 electronic implantable device patients have had an MRI despite the risks, and of this group nearly 20% reported experiencing problems with their device afterwards.

To add to the confusion, some cardiologists have published special protocols that describe how to allow patients with cardiac pacemakers to receive MRI scans. Some say that for certain patients, the diagnostic benefit from MR imaging versus other pacemaker-compatible choices outweighs the risks.

If someone has recommended that you or your loved one with a pacemaker have an MRI for diagnostic purposes, make sure that you point out the pacemaker. You might be surprised what can be overlooked in an emergency room or other setting where the treatment team doesn't know their patient. You might also want to have a quick consultation with your cardiologist about your concerns and possible alternatives to an MRI.