How does an MRI scanner work?
Your body is composed of small particles called atoms. Hydrogen atoms, i.e. in water, make up 95% of the body. Normally, these hydrogen atoms within your body spin around at random. However, when you are placed inside a strong magnetic field, the hydrogen atoms line up and spin in the same direction as the magnetic field. When a radio wave is transmitted through the body, the hydrogen atoms give off a signal. That signal, with the aid of a computer, becomes the source of MRI information to produce two-dimensional images or three-dimensional volumes of a part of your body.