Ask the doctor: Do I need an MRI scan of my heart?
Q. I am an 84-year-old man with atrial fibrillation, mild heart failure, and well-controlled high blood pressure. My doctor had me wear a Holter monitor and get a SPECT scan (which showed mild nonischemic cardiomyopathy). Now he wants me to have a cardiac MRI. What information would this test give that he doesn't already have?
A. Assuming that the results of your tests haven't made your doctor suspect something else is going on, the short answer is that you probably don't need a cardiac MRI. The single-photon emission computed tomography (SPECT) scan you had generates three-dimensional images that show how blood flows through your heart. It is good at identifying narrowings in the coronary arteries that may hinder the flow of blood to part of the heart muscle. The Holter monitor you wore detected whether your heart slipped into irregular rhythms over the course of one or two days.