Having an MRI scan

This leaflet has been designed to improve your understanding of your forthcoming treatment and contains answers to many of the common questions. If you have any other questions that the leaflet does not answer or would like further explanation please ask your surgeon.

What is an MRI scan?

Magnetic resonance imaging (MRI) is a method of building up a detailed picture of your body and its organs. Unlike CT (computerised tomography), which uses x-ray radiation, it uses magnetic fields to create the pictures.

Is it safe?

MRI scan are considered safe with very little risks or side effects.. Because of the magnets involved, MRI must not be performed on people with certain metal implants in their bodies such as pacemakers, inner ear implants, surgical clips within the head and some artificial metallic heart valves. If you have ever had metal fragments in your eyes, it will be necessary for you to have an x-ray of your eyes to ensure that no fragments still remain. It is important that you let us know if you have had any metal or medical devices in your body.

During the scan, the magnets make a wide range of loud noises; banging, buzzing and rumbling. You will be provided with headphones to protect you from these.

Will I need an injection?

Some patients may need an injection to improve the quality of the scan. In most patients, the injection is given in a vein in your elbow (the same place as a blood test).

How long will the MRI scan take?

It usually takes around 30 minutes to scan one part of your body. It will take longer to scan more than one part. The length of the scan also varies depending upon the issue that your doctor is trying to investigate. It is important to remember that if the scan takes a little longer it does not necessarily mean that there is something wrong.

Can I eat or drink?

You may eat, drink and continue to take any medication prior to your MRI scan. If you are having a scan of your stomach, you may be asked to starve for four hours before your scan.

Does it hurt?

No. An MRI scan is painless, but you must be able to keep very still and lie quite flat. The MRI scanner is like a tunnel and some people do feel claustrophobic.

Is there anything else I need to know?

It takes a long time to look at all the pictures that your scan produces, so the report will not be available for several days. You will be sent an appointment for a review in the Outpatients Department to discuss the findings of your scan and any further treatment that might be necessary.

Adapted from:

British Association of Oral and Maxillofacial Surgeons (opens in a new tab)