Magnetic Resonance Imaging (MRI)
What is MRI?
Magnetic Resonance Imaging (MRI) uses a very powerful magnet and radio-frequency pulses to collect signals that are then processed by a computer to form a picture of the body part being studied. Images line up like slices from a loaf of bread.
MRI gives a detailed picture of the soft tissues of the body e.g. muscles, ligaments, brain tissue, discs and blood vessels.
Who cannot have an MRI scan?
Anyone with a pacemaker, certain clips in the brain, cochlear implants or metal chips in their eye must NOT go near such a powerful magnet. Most metal put in at surgery (hip replacements and metal rods) is safe. You will need to complete a safety questionnaire prior to the procedure.
Is an MRI scan safe?
An enormous amount of study has not demonstrated any danger from an MRI scan. It uses no x-ray radiation. The radio wave pulses are of similar frequency to your radio. The powerful magnet does not have any known side effects.
Will it hurt?
MRI is painless but may be noisy, and since scans take between 30 and 40 minutes you may become a little uncomfortable lying still for that period.
In most cases there is no special preparation and you can eat and drink normally with a 2 hr fast.
If you think or know that you may have problems with enclosed spaces (claustrophobia) then it is advisable to contact us prior to the scan.
There are several techniques that the technologists will employ to assist you. However, if sedation is required you will need to fast for 2 hours prior to attending and be escorted by someone who will accompany you home. You will not be permitted to drive home under any circumstances and will need to remain under observation for some time after the completion of the scan.
If you are taking any pain medication, please do so such that its peak action corresponds to the intended scan time. (12 hr restrictions).
Other medications should be taken as normal.
Do not wear eye make-up or hairspray if you are having a head scan.
On arrival, you will be asked to complete a safety questionnaire to ensure that you are eligible to be scanned. Certain implants and metallic objects will exclude you from an MRI scan.
If you have worked in the welding industry or have ever had metal fragments in your eye then you MUST inform us so that you can have eye x-rays to ensure that no fragments remain. It is imperative to have any metal fragments removed prior to the scan.
You will be asked to change into a hospital gown to avoid any metallic objects being inadvertently taken into the scanner. You will be provided with a secure site to store your valuables including watch and wallet. Any credit cards taken into the scanner will have their magnetic strips erased.
For some examinations your heartbeat may need to be recorded by placing small patches and wires on your back and chest.
During the scanning process
Prior to the scan beginning a special signal receiving coil may be placed around your knee, shoulder or abdomen (depending on the nature of the examination).
You will be asked to lie on a movable table which positions the body part to be imaged in the centre of the tunnel.
During the examination you will hear a series of loud knocking noises and may feel a slight vibration. Headphones or earplugs will be provided.
It is important that you remain as still as possible during the scan otherwise the images taken will appear blurry.
Constant communication, both verbal and visual, is maintained throughout the scan to ensure that you are comfortable and updated on the progress of your examination. If at any time you become uncomfortable, a buzzer enables you to communicate with the technologist.
Will I require an injection?
Most MRI tests will not require a contrast injection, however in certain circumstances it may improve the accuracy of the scan. This injection (gadolinium solution) is usually into an arm vein. It is not like the contrast used in x-ray examinations. Let staff know you have renal / kidney problems.
If sedation is required it is injected into a vein through thin plastic tubing in the elbow area or the back of the hand.
What if I’m pregnant?
If you are pregnant, or could be pregnant at the time of your appointment, please contact us prior to that time so that the situation can be discussed with your referring doctor.
MRI is usually avoided in the first trimester of pregnancy unless the diagnosis cannot wait and your doctor considers MRI to be the best investigation.
When will I get my results?
MRI investigations contain specialised and complex information. A large number of images are produced and review of these images may take several hours and or days
Usually the report is available to your referring doctor the next working day.
For some examinations MIA may electronically send your examination for additional super-specialist opinion elsewhere in Australia.
Please bring any previous x-rays with you on the day of your examination.