What is MRI?
MRI stands for Magnetic Resonance Imaging. A combination of a strong magnet and radio waves produces detailed pictures of the inside of your body in any plane. Unlike x-rays and CT (Computerised Tomography) scans, MRI scans do not use radiation.
An MRI scan can help us find the cause of your problem and the best treatment options for you. MRI scans are particularly good at identifying problems in the spine, brain and joints and are much more detailed than a standard x-ray.
Preparation for your scan.
Please check your letter carefully for any specific information about preparing for your MRI scan and to ensure that you know which of our 3 scanners you need to go to.
If you have any mobility issues could you please let your doctor know or contact the MRI bookings clerks so that we can ensure that this is taken into account when booking your appointment.
If you think that you have ever had an accident involving metal fragments in your eyes (e.g. from welding or grinding) then you must phone our bookings clerks to arrange to come in to have your eyes x-rayed, if necessary. This can be done on another day prior to your scan or you could come in early on the day of your scan to allow time for the x-ray.
You may prefer to arrive for your scan in clothes which do not contain metal, for example you could wear a zip less tracksuit, shorts or an elasticated skirt. If you do this you will not have to change for your scan. It will not be a problem if you do need to get changed.
The scanner is a short tunnel, so if you suffer from claustrophobia (fear of enclosed spaces) please let us know before you come for your scan. Many patients worry about this aspect of the scan but find that it isn’t as bad as they had imagined or been told. If necessary, somebody can stay with you in the scan room during the scan.
There is usually no need for any special preparation before your scan. On the day you will probably be able to eat and drink as normal and take any medicine you have been prescribed - if not, we will tell you when you book your appointment.
What will happen?
When you arrive a member of staff will complete a safety checklist with you to make sure that you can be scanned, and will answer any questions that you may have.
You will need to remove all metal objects such as zips, jewellery, hair grips and so on before entering the scan room because of the powerful magnet that is used to scan. Credit cards are also affected by the magnet - you can leave these and other valuables in the lockers provided. Please do not wear mascara if you are having a scan of your head or eyes as it contains fine metallic particles which affect the pictures.
We will probably ask you to change into a gown if you are wearing clothes that contain metal.
The radiographer will ask you to lie on the scanner bed and position you correctly. Every effort will be made to make you comfortable as you will need to keep very still during the scan to avoid blurring the pictures.
If we are scanning your chest or abdomen, we may ask you to hold your breath for a moment during each scan.
There is a chance that we may have to give you an injection of contrast medium as part of your scan. There is more information about this in the ‘Contrast Media’ section.
A scan usually takes 20 - 30 minutes, depending on the area of your body that is being scanned. Although we try to keep to appointment times sometimes scans can take longer than anticipated due to technical reasons or patient condition. If we are running late when you attend for your appointment we would appreciate your understanding.
MRI is a completely harmless procedure, but the scanner is very noisy when it is taking pictures so we will provide you with ear protection. We will be able to play music during your scan so you might like to bring a CD with you to listen to.
There are no after-effects from your scan so you can carry on with all your normal activities (driving, for example) straight away.
Sometimes we need to give you an injection of contrast dye before or during the scan. This contains gadolinium, which is very safe and rarely causes allergic reactions or other problems. Unlike some other contrast media it does not contain Iodine.
For some abdominal and gynaecological scans we will need to give you a drug called Buscopan which is necessary to relax the bowel thus reducing movement blurring on the pictures.
Before giving you any drugs or contrast media we will check thoroughly that it is safe to do so and ask for your consent.
If you are pregnant, national safety guidelines recommend that we do not carry out an MRI scan unless it is clinically urgent. The doctor who refers you for the scan will decide with the radiologist (doctor who reads the scan) if your scan is necessary or if it can wait until after your pregnancy. Many pregnant women have had MRI scans with no reported problems.
Please do not hesitate to contact the department if you have any concerns about this.
What happens after the scan?
As soon as the scan is finished, you can go home or back to your ward if you are an inpatient.
You can eat, drink and resume normal activities straightaway.
The results will be sent to the doctor who referred you. If you make an appointment 2 weeks after your scan, your results should be available. For urgent problems, the results will be available sooner.
If you are an inpatient, the results will be given to the doctors looking after you on the ward.