A CT scanner

Spot the difference

Magnetic resonance imaging (MRI) vs computerised tomography (CT)





It is non-invasive

It is very useful for producing images of soft tissues, such as the brain, eyes, ligaments and cartilage

It can produce images in any plane (eg horizontal or vertical)


It is non-invasive

It is very useful for imaging hard tissues such as bone

It is quick – a scan can take as little as five minutes

It produces highly detailed images

It can be used on patients with metallic implants



It is expensive

It cannot be used on patients with artificial pacemakers or metallic implants

It is not portable


It is not portable

Some patients are allergic to the contrast dyes that are injected for some CT scans

It exposes the patient to radiation



Lead image:

A CT scanner.

Vila H./Flickr CC BY NC


About this resource

This resource was first published in ‘Inside the Brain’ in January 2013 and reviewed and updated in November 2017.

Inside the Brain
Education levels:
16–19, Continuing professional development