MRI and CT Scan

What it involves

An MRI scan uses strong magnets and radio waves to create detailed images of soft tissues, the brain and joints, without ionising radiation. A CT scan uses a series of X-ray images combined by a computer to produce cross-sections of the body, and it exposes you to a higher dose of radiation than a standard X-ray. Both are done in large scanners.

Who it is for

They are for people whose doctor needs detailed pictures to investigate symptoms, injuries or conditions. Your doctor chooses between them based on what must be seen, and a request from a doctor is usually required. Tell staff about implants, pacemakers, pregnancy and allergies.

How long it usually takes

A CT scan often takes only minutes on the scanner, while an MRI usually takes longer, often thirty minutes or more. Preparation time adds to the visit.

What to expect

You lie on a table that slides into the scanner. MRI is noisy, and you are given ear protection. The space is narrow, and you need to keep still. For some scans a contrast dye is injected. A radiologist reports the images and your doctor explains the result.

Aftercare

You can usually return to normal activities. If contrast was used, drink fluids as advised and report any reaction. Ask how and when you will receive the results.

When to seek it

Your doctor may recommend a scan to investigate symptoms or follow a condition. Tell the team if you feel anxious in enclosed spaces, as there are options to help.

What affects the cost

Cost depends on the type and area scanned, the use of contrast, who reports the images and the facility. HealthNaro shows a price only where a clinic has supplied a figure with a source and date.

Read more in our guide: X-ray, ultrasound, CT and MRI scans: how they differ and what to expect.

This page is general information and not medical advice. In an emergency, contact your local emergency number.

Sources: NHS; NHS; World Health Organization.