What is MRI ?
Magnetic Resonance Imaging is a diagnostic scanning technique based on the principles of magnetic resonance. MRI uses a strong magnetic field and radiofrequency moves to produce detailed images of the internal organs and tissues.
Is it safe?
There are no known risks or side effects associated with MRI. Unlike traditional X-rays and CT scans MRI does not require the use of ionising radiation. MRI scans can therefore be performed repeatedly without adverse effect.
During the scan, the main magnetic field strength is altered using electromagnetic coils. This causes a wide range of sounds during the scan procedure including banging, buzzing and rumbling noises These are loud and we strongly recommend that you use the earplugs or headphones provided. The scanner table has a patient weight limit, but this varies between centres. Please contact us if you weight over 150kg (23st).
IMPORTANT SAFETY INFORMATION
It is not possible to have an MRI examination if you have:
- A heart pacemaker
- Surgical clips within your head
- Certain metallic heart valves
- Inner ear implants (e.g. cochlear)
- Some neuroelectrical stimulators
- Metal fragments within your eye or head
If you have any of the above please inform the Centre as soon as possible. (Please Note: If you have ever had metal fragments in your eyes due to a penetrating injury and have not had your eyes checked you will require an X-ray of your eyes to ensure there are no fragments still remaining.)
Also please consult the Centre if:
- You are or maybe pregnant
- You have had recent surgery that has required the insertion of metal including joint replacements and clips. The scan may have to be delayed for a few weeks to allow time for the body to heal properly around the surgical site. If you have any fillings or other dental fixtures, the MRI examination can still be carried out.
Can I eat and drink?
You may eat, drink and continue to take any medication prior to your MRI scan. If you are having a scan of your abdomen you may be asked to fast for four hours before your scan.
Will it be Painful?
No. An MRI scan is a painless procedure, but you must be able to keep very still and lie quite flat. If you are unable to keep still or lie flat please contact us.
Will I need an injection
Some patients may need an injection to enhance the images, usually in parts of the body which have poor nature contrast.In most patients the injection is given in the vein in your elbow (the same place as a blood test). The injection should have no adverse effects.
Please note that this is not the same kind of injection which you may have had before during X-ray procedures such as CT.
How long will it take?
For one part of your body to be scanned it generally takes about 15-25 minutes. Therefore, it will take proportionately longer to scan more than one part of your body. The length of the scan may also vary depending upon the diagnosis being sought, for example, it often takes longer to produce high resolution images when very small anatomical structures ore being scanned. The important thing to remember is that there is no connection between the length of the scan and finding something wrong.