Magnetic resonance imaging, or MRI, is a way of obtaining very detailed images of organs and tissues throughout the body without the need for x-rays. Instead, MRI uses a powerful magnetic field, radio waves, a rapidly changing magnetic field, and a computer to create images that show whether or not there is an injury or some disease process present. For this procedure, the patient is placed within the MR scanner—typically a large, tunnel or doughnut-shaped magnet that is open at both ends. The magnetic field aligns atomic particles called protons that are present in most of the body's tissues. Radio waves then cause these particles to produce signals that are picked up by a receiver within the MR scanner. The signals are specially characterized using a changing magnetic field, and computer-processor to create very sharp images of tissues as "slices" that can be viewed in any orientation.
An MRI exam causes no pain, and the magnetic fields produce no known tissue damage of any kind. The MR scanner may make loud tapping or knocking noises at times during the exam; using earplugs prevents problems that may occur with this noise. You will be able to communicate with the MRI technologist or radiologist at any time using an intercom system or by other means.