Preparing for an MRI scan
Inform your doctor if:
- You have any medical devices or implants in your body. Examples include a cardiac pacemaker or defibrillator, implantable pump, electronic stimulator, clips, staples, screws, rods and plates. Bring along the device/implant information card (if any) during your scan appointment.
- You are pregnant or suspected to be pregnant.
- You have claustrophobia or fear of confined spaces. Your MRI scan may be performed under sedation. Please highlight this when making an appointment. You will need to fast if sedation is required.
In most cases, surgical staples, plates and screws pose no risks during MRI if they have been in place for more than 4 weeks.
You will need to change into a gown and remove all loose items such as jewelleries, watch, keys, coins, smartphone, wallet and cards. You may keep your personal belongings in the locker provided.
You will be asked to fill in a pre-MRI questionnaire to provide information on your medical history. Indicate on the questionnaire if you have any medical device/implant or aesthetic procedures performed such as permanent eyeliner, magnetic eyelashes and skin tattoo. The radiographer will go through the questionnaire with you and explain how the scan will be performed.
During the MRI scan
You will need to lie on the scan table, and headphones or ear plugs will be provided to you. A call bell/button will also be provided in case you need to call the radiographer during the scan.
The body region to be examined will be covered by a coil which acts as signal receiver.
The scan table will move into the magnet bore or tunnel so that the scan region is positioned at the centre of the magnetic field. There will be intermittent knocking and humming sounds throughout the scan. This is caused by the changes in gradient fields in the magnet.
It is important that you remain still during the scan. Any body movement will cause blurry images and the scan will have to be repeated.
You should not feel any discomfort during the scan. However, some patients may feel warm after some time in the magnet. This is normal but if it bothers you, you can press the call bell and inform the radiographer.
Sometimes, your doctor may order your MRI scan with contrast injection. A contrast medium acts like a dye when it is injected into your blood vessel. It helps to delineate the body organs and soft tissues for better visualisation.
Allergic reaction to MRI contrast is extremely rare. Should you feel any discomfort after the contrast injection, inform the nurse or radiographer immediately.
A typical MRI scan will take about 30 – 45 minutes for one body region. It will take longer for multiple body regions, complex studies or if contrast injection is required. MRI under sedation will also take longer time.
After the MRI scan
- You may leave and go about your day as usual after the scan.
- If you had your MRI scan under sedation, the nurse would monitor you for a short period until you are fit to be discharged.