A MRI or magnetic resonance imaging is a test that allows doctors to see a detailed image of certain parts of the body, including the head, chest, breasts and abdomen. A MRI scan does not used radiation to produce an image, but rather creates a 3D image of the inside of the body. It is very detailed and can help doctors to pick up on abnormalities in the body. The test can be very useful, as it can help doctors to pinpoint the exact area causing problems.