-- Question: Is it true that I can never get an MRI (magnetic resonance imaging scan) again once I have a pacemaker?
Answer :MRI, CT, and PET are three different techniques for getting images of the heart. MR is a magnetic system, it doesn't use radiation. But because it involves the use of very powerful magnetic fields, in general, anybody with a pacemaker or a defibrillator should not have an MRI examination performed. Now that said, there are MRI compatible devices that are being developed and at some centers there is some experimental work using MRI in patients with pacemakers. However, in 2008 it is our recommendation that patients with metal in their bodies -- and that includes pacemakers or defibrillators-- not have MRIs done.
Now a CT scan is a form of x-ray. Both CT and MRI produce very detailed three-dimensional pictures of the heart. They just use different approaches to achieve the same result. And anybody with a pacemaker or a defibrillator can have a CT scan of their heart done perfectly safely. The difference between the MRI and the CT is that the MRI involves no radiation and the CT is an x-ray system.
PET imaging is another form of imaging of the heart that uses an isotope which allows the imaging technique to detect metabolic activity. So it's one of the imaging techniques that is used to determine whether or not an area of heart muscle is in fact still living or whether it is completely scarred, and that may affect a decision about whether a patient needs bypass surgery or would benefit from bypass surgery or a stent procedure.