Magnetic Resonance Imaging (MRI)

MRI stands for magnetic resonance imaging. An MRI scan uses a combination of a strong magnet and radio waves to produce detailed pictures of the inside of your body.

An MRI scan can help to find out what is causing your problem and help your doctor to find the best treatment for you.  An MRI scan provides much more detailed pictures of your body than an ordinary x-rays. It is particularly good at identifying problems in the spine, the brain and blood vessels. It is also helpful for looking at other parts of the body, often when other types of scan have not given a full picture. Unlike x-rays and CT (computerised tomography) scans, MRI scans do not use radiation.

MRI is a very safe procedure for most patients. However, patients with heart pacemakers and certain other surgical implants, for example a cochlear implant, cannot be scanned. There may also be a problem if you have ever had metal fragments in your eyes. You must let us know beforehand if this is the case. (Contact details on your appointment letter and at the bottom of this information ) You will be asked to complete and sign a safety questionnaire before your scan to make sure it is safe for you to be scanned.

National Safety Guidelines recommend that we do not scan pregnant women unless the scan is clinically urgent. The doctor who refers you for the scan, along with the radiologist (doctor who uses x-ray to diagnose and treat illnesses) will decide whether they believe your scan is necessary.

Many pregnant women have had MRI scans at Leeds Teaching Hospitals and at other MRI centres worldwide, with no reported problems. If you have been referred for an MRI scan when you are pregnant and would like further information, please do not hesitate to call us.

If you are claustrophobic we recommend that you speak with your GP who may prescribe medication to help you relax. Please note that we cannot prescribe this for you in the department. Please inform the radiographer if you are anxious.

If you cannot have a scan, for example if you have a pacemaker, the radiologist may suggest an alternative type of imaging. This could be a CT scan or an ultrasound scan.

The radiographer (member of the radiology team trained to carry out scans) will ask you if you are happy for the scan to go ahead. This is called verbal consent and may only involve the radiographer checking you are booked for the correct scan. If you do not wish to have the scan or are undecided, please tell the radiographer. It is your decision and you can change your mind at any time. Please bear in mind that not having the scan may delay your diagnosis as the doctors may not have all of the information that they need. Please remember that you can ask the radiographer any questions you have at any time before, during or after your scan.

In most cases you do not need to do anything to prepare for the scan. You can eat and drink as normal. If you are taking any medication, please continue to take this. If we do need you to do anything in preparation, we will send you information about this with your appointment letter.

We may ask you to change into a hospital gown if any metal fastenings, such as zips or hooks and eyes, on your clothes are close to the area we are going to scan. This is because the fastenings may spoil the pictures. Alternatively you may wish to arrive wearing clothes without metal such as t-shirt, jogging bottoms and sports bra for ladies.

You will need to empty your pockets of any coins, as these may be pulled out by the magnet and fly into the scanner. You will need to take off your watch and take any credit cards or travel cards with magnetic strips out of your pockets. The scanner can affect these and stop them from working.

If we are scanning your head, you will need to remove any dentures that contain metal. Dental fillings will not affect the scan. Hairclips and wigs must also be removed if they contain metal.

Before the scan, you will be given the opportunity to ask the radiographer any questions you have.
We will ask you to lie on the scanner bed where you will be made as comfortable as possible. If this is not comfortable, please tell us, as you will need to keep very still during the scan. It is important that you do not move, or the pictures could be blurred and the scan will have to be repeated. Once you are positioned correctly, we will move you into the scanner – the part of your body that we are scanning must be in the centre of the machine. For scans of the chest or abdomen, you may be asked to hold your breath for a short while.
When the scanner is working, it makes a loud banging noise. We will give you headphones to wear to reduce the noise. You can listen to music while you are being scanned – so please bring in a CD of your choice! You will also be given a buzzer to press if you need to attract our attention during your scan.

This depends on which part of your body is being scanned and the information that your doctor needs. The radiographer will tell you how long he/she expects your scan to take. Most scans take between 20 and 30 minutes, although some can take an hour.

The scan should be completely painless. The most difficult part is keeping still. Make sure you are as comfortable as possible before we start and try to relax. The scanner is a short tunnel which is open at both ends.

If we are scanning certain areas of your body, we may need to give you an injection of contrast dye, The dye shows up on the scan and gives us more detailed pictures, particularly of your blood vessels. The injection will be given by inserting a small needle into a vein in your arm or your hand. If you would like more information about the injection, please ask the radiographer before your scan.

If we are scanning your abdomen or pelvis we sometimes need to give you a muscle relaxant called Buscopan. This reduces your bowel motion and so reduces blurring on the images. It also relaxes the muscles around your eyes and vision may be blurred. It should subside by the time your scan is completed. If not please inform the Radiographer who will advise you to remain in the department until your vision returns to normal.

The contrast dye contains gadolinium, which may, rarely, cause allergic reactions. The most common allergic reactions can present as nausea and vomiting, sneezing, wheezing, runny nose, eye irritation, itching, hives, skin rash and or swelling of the face.

If you have the injection of contrast dye most allergic reactions occur immediately. However an allergic reaction can very rarely occur up to two days after the scan. If this happens, please contact the MRI department where you had your scan for advice. Alternatively, if it is out of hours, contact your local A&E department.

After having Buscopan some patients very rarely develop pain and redness in both eyes. This occurs in the 24hrs after the test. If this happens please attend your local A&E. Please remember that this is very rare.

Current guidelines state that it is safe to breastfeed following the injection of contrast dye as so little dye is passed to the baby via the breastmilk.

Alternatively, if you prefer, you can express and discard the breast milk for 24hrs following the scan.

Unfortunately, we are not able to offer childcare facilities and your children cannot go into the scan room with you. If you need to bring your children with you, please bring along an adult who can look after them while you are having the examination.

As soon as the scan is finished, you can go home, or back to your ward if you are staying in the hospital. You can eat and drink as normal and resume your usual activities.

The pictures taken during the scan are carefully studied by the radiologist who will produce a detailed report.

The results will be sent to the doctor who referred you for the scan, usually a hospital Consultant (specialist). Most results are available to your Consultant within 1 to 2 weeks. For more urgent problems, they may be available sooner.  You may already have an appointment to go back to your Consultant for the results.  If not and you have not heard anything after 2 weeks, please contact your Consultant’s secretary.