Magnetic Resonance Imaging, or MRI, is a test that produces a uniquely detailed and high-quality picture of the inside of the body. It is done using a strong magnetic field along with radio waves. A computer then analyzes the signals given off by hydrogen within the tissues of the body and uses those signals to develop an image. It can be done on any part of the body: the brain, chest, heart, joints, abdomen, or extremities.
MRI uses no radiation, is painless, and is extremely safe. However the machine can be loud while it is running, and patients who don’t like the feeling of being in confined spaces might feel uncomfortable. MRI might also not be appropriate for patients who have certain types of metal inside their bodies such as pacemakers, shrapnel, or metal aneurysm clips.
When you arrive for your MRI, you will usually be instructed to remove your clothing and be given a gown to wear. Because MRI works using a strong magnetic field, it’s very important that you remove all metal objects from your body, including watches, earrings, hearing aids, and hair clips. Some tests require an injection of a contrast dye to help specific parts of the body show up better in the image. You will lay down on a table and usually be offered earplugs or headphones to cancel the noise from the machine. Then the table moves you through a ring, tube, or tunnel shaped machine that makes thumping, hammering sounds. It’s important to stay as still as possible to get as clear an image as possible. An MRI can take as little as 15 minutes or more than an hour, depending on the area being examined.