Magnetic resonance imaging

By Reese Lipscomb

The EM wave type is a radio wave

It is a procedure used in hospitals to scan patients and determine the severity of certain injuries. An MRI machine uses a magnetic field and radio waves to create detailed images of the body. Common reasons people go in to get an M.R.I. are for a sprained ankle or back pain. Patients who have any metallic materials within the body must notify their physician prior to the examination or inform the MRI staff. Metallic chips, materials, surgical clips, or foreign material (artificial joints, metallic bone plates, or prosthetic devices, etc.) can significantly distort the images obtained by the MRI scanner. Raymond Vahan Damadian was the first to perform a full body scan of a human being in 1977 to diagnose cancer. Damadian invented an apparatus and method to use NMR safely and accurately to scan the human body, a method now well known as magnetic resonance imaging (MRI).

In MRI, a patient lies in a large cylinder that is equipped with a powerful magnet, a radio wave emitter, and a radio wave detector. Particles in the bones and soft tissues behave like tiny magnets and can be lined up. When the MRI machine causes the orientation of the particles to flip, they produce radio waves. The released energy is detected by the radio receiver and used to create a map of the different tissues.