What is an MRI?

Magnetic resonance imaging (MRI) uses powerful magnetic fields and radio waves to produce detailed images of structures in the body.

How it Works

The human body is mostly made up of water. Water molecules (H2O) contain hydrogen nuclei (protons). These protons are constantly spinning with the body’s natural magnetic field.

When an MRI scanner emits magnetic waves to the body, it aligns to the protons. The scanner also sends out a radio frequency current that creates a varying magnetic field. This causes the protons to flip their spin.

When the field is turned off, the protons return to their normal spin in a process called precession. During that process, a radio signal is produced that can be measured by the scanner and computed into an image.