CT scans and MRIs are both used to capture images within your body. The biggest difference is that MRIs use radio waves and CT scans use X-rays. With a CT scan, an X-ray machine rotates around the patient’s head or body while a computer collects all of the data from each angle.

This is repeated for each layer until we have a 3D image of the inside of your head or body in cross-section.

MRI stands for “magnetic resonance imaging” which uses strong magnetic fields instead of radiation to produce images. An MRI scanner has powerful electromagnets, similar to those found in an electric generator, but they are turned off by default when not in use as it generates heat.

These magnets produce a field that aligns the atomic nuclei in your body, and then pulses of radio waves are used to measure how these atoms react.

A CT scan has more radiation exposure than an MRI because it requires multiple X-rays to be taken at various angles around the patient.

An MRI uses magnetic fields which do not require any additional external energy or sources such as from an X-ray machine; there is also no need for contrast material with MRIs like you would have to provide for a CT scan, either intravenously (IV) or orally if needed.