MRI – Magnetic Resonance Imaging
What is an MRI
MRI (Magnetic resonance imaging) is a method of looking inside the body.
Magnetism (instead of x-rays) is used to produce clear pictures of your head, spine, or other parts of your body and to distinguish between normal healthy tissue and diseased tissue.
An MRI is essentially a big magnet. It uses radiofrequency pulses to align certain protons in our bodies – when these pulses are stopped, the body re-aligns its protons and the energy that the body uses to do this is “read” out into the MRI machine and transformed into images that the Radiologist can interpret.
MRI imaging does NOT use any radiation and it is therefore the preferred image modality when it comes to children and infants.
Our Magnet is a tunnel – and both your head and feet will be “open” during the procedure – we might put on a head or body coil – this looks very much like a helmet. That is why, we like to think of our MRI as a “spaceship” – and most of our paediatric patient’s agree that it’s kind of “cool”.
MRI doesn’t need to be a scary experience – and it is therefore very important to read this information section so that you are well informed prior to the examination.
What happens during an MRI scan?
The technologist will position you on a special table within the magnet which is not a closed tunnel as it is open at both your feet and head area.
You will be able to communicate with the technologist during the scan.
It is important to hold very still and relax.
You may be asked to hold your breath for up to 30 seconds.
The machine makes a loud noise but the headphones provided will block out most of the noise.
MRI scan may require the use of a contrast-agent given intravenously to assist in visualization of certain structures in your body.
An examination lasts between 30 -90 minutes, depending on the body part imaged and whether contrast is required.
We adhere to the SASPI Guidelines from Red Cross Childrens War Memorial Hospital, Cape Town, for all our Paediatric imaging.
Available from the rssa website
We also adhere to the RSSA guidelines in terms of Gadolinium contrast agent used and will ONLY administer contrast if it is deemed necessary for a complete examination.
We have a pre-booking system and your doctor will complete a Radiology request form for the specific examination.
You then phone our Department and ask the friendly staff to be put through to the MRI section where you will be allocated a specific time slot and date
- Referral letter
- Medical aid card
- You will be asked to lock your valuables up since you may not take it into the room. The magnet will destroy any electronics and magnetic strips on bank cards. If at all possible you are advised to leave valuables at home.
- If you bring your child:
- Clean set of clothing
- Bottles, milk, nappies, dummies etc
- Favourite soft toy – if applicable
- Treat to enjoy after the scan
- Your clinical condition will determine if admission is needed
- The hospital porter or staff nurse will accompany you to the MRI for your examination
- Here the MRI staff will welcome you and ask you to fill in a questionnaire prior to the MRI examination
The MRI staff will ask you to fill in a questionnaire for MRI safety.
- Please bring the referral letter from your doctor with you, once an appointment time for the study was made.
- We will obtain authorization from your medical aid on the same day as the study is to be performed.
- No special preparation is needed prior to the examination.
- Please wear loose clothing without zippers or metallic parts.
In case of claustrophobia, light sedation is available for adults to make the scan bearable. We do have an anesthetist available in severe cases, but this must be arranged well in advance since she is only available on Wednesdays on request.
In children < 15 kg/4 years – we advise sedation for the procedure as the machine makes a big noise and some children find this alarming.
We have a qualified nurse at the MRI that will administer the sedative to your child in the form of an anti-histaminergic agent (Chloralhydrate). The agent is safe and will only make your child feel sleepy without suppressing normal respiration (breathing)
The sedation will take approximately 20-30 minutes to take effect.
If your child is still very scared or uncooperative after the sedation was given the examination might be postponed and an anaesthetist contacted for proper sedation and monitoring of your child on a scheduled date
- This will be done via your Paediatrician after consultation with our Radiologist
- It is then advised to keep your child nil per mouth (no eating or drinking) for 8-10 hrs prior to the MRI procedure.
- Smaller children (4 year and younger) need to be nil per mouth (no eating or drinking) for 2 – 4 hrs prior to the MRI procedure.
- Your pediatrician & anaesthetist will confirm the exact NPO time period with you.
Once your child is sleepy the MRI staff will accompany you inside the MRI scanner and position your child on the MRI bed
You are welcome to sit with your child in the MRI scanner and our staff will provide you with noise cancelling headphones and a chair
- No cellphones, earrings, metal wedding bands, coins, credit cards, pocket knives or any other metal objects
- If you had recent orthopaedic or cardiac surgery it is imperative that you inform the MRI staff as the magnet may cause a reaction with the metal implant
- Dentures or any Titanium metal dental implants are MRI safe
Once the examination is completed you can eat and drink normally. There are no side effects associated with MRI radiofrequency waves, as no radiation is used. If you or your child had sedation, he/she will be monitored after the MRI procedure by the Anaesthetist responsible.
Finding out the results
- Assessing the multiple images, compiling and typing the report and producing a CD with your images may take at least 40 minutes (we thank you for your patience).
- Your referring doctor will then evaluate your images and report regarding your further management.
Please inform us if any of the following applies to you, as MR works with a strong magnet:
- Aneurysm clips(s)
- Cardiac pacemaker
- Implanted cardioverter defibrillator
- Magnetically-activated implant or device
- Neurostimulation system
- Spinal cord stimulator
- Cochlear implant or implanted hearing aid
- Insulin or infusion pump
- Implanted drug infusion device
- Any type of prosthesis or implant
- Artificial or prosthetic limb
- Any metallic fragment or foreign body
- Any external or internal metallic object
- Other implants
Any metallic substance on your person can affect the quality of the diagnostic images. It can cause discomfort or even injury to you when placed inside the magnet.
Remove all: Watches, jewellery, hairpins, glasses, wallets, hearing aids, firearms, other metallic objects.
Please tell us if you are pregnant.