MAGNETIC RESONANCE IMAGING

by National Society for Epilepsy

Magnetic resonance imaging (or MRI) is a scanning technique which produces very clear, detailed pictures of the brain (and other parts of the body). These pictures are very much more detailed than those from other scanning techniques, and can help determine whether or not there is a structural cause for someone's epilepsy. It is important to remember that MRI is a diagnostic technique and not a form of treatment.

The National Society for Epilepsy owns the only MRI scanner in Europe dedicated solely to epilepsy.

Operation

MRI uses a very strong magnetic field, far stronger than the earth's magnetic field, and this scans the hydrogen protons within the human body. Very sophisticated electronic hardware and computer software is then used to produce the images on both a computer screen and on film, so that they can be studied by a specialist.

Application to epilepsy

An MRI scan gives far better anatomical details than other diagnostic techniques. In epilepsy this has meant that even very small abnormalities, which may have been missed by other scans, can be seen. In some people it is possible to remove the abnormal area by neurosurgery.

Side-effects

Unlike an x-ray, MRI is not known to have any harmful side-effects. There are some people for whom it would not be possible to have a scan. For example, people with pacemakers, cerebral aneurysm clips, and some other surgical implants, will not be able to have an MRI scan because of the strong magnetic field.

The scan

Before someone can have a scan, a form has to be completed to make sure that there is no reason why a scan cannot be carried out. The person is then asked to remove any jewellery, hairclips, hearing aids, credit cards, coins, keys, and anything else in their pockets which will interfere with the scanning procedure. They are then asked to lie down on a flat surface, which then moves inside the scanner.

The scan does not hurt, but it is very noisy so earplugs are available. A two-way intercom means that there is constant contact whilst the scan is being carried out. Usually the scan lasts about half an hour, and all the person has to do is lie there and keep still.

Referral

Everyone has to have a medical referral, either from their GP or consultant, before they can have a scan, because the doctors at the NSE have to assess each person's suitability. If you have epilepsy yourself or you know someone with epilepsy who would like a scan, please discuss the possibility with the medical practitioner who manages the epilepsy treatment.