What is MRI scanning?
MRI stands for Magnetic Resonance Imaging. A magnet combined with completely safe radio waves allow pictures to be generated by exciting part of the water molecules inside our body.
MRI is entirely painless and non-invasive. It involves no X-rays or other types of radiation. There are no known side effects. However, you cannot have an MRI if you have some types of metal in your body. Modern joint replacements are made of titanium which is safe, but we will check very carefully before your scan.
What does the equipment look like?
The MRI scanner is like a short tunnel surrounded by a circular magnet. You lie on a bed and another smaller magnet is placed behind, or around, the part of the body being examined. The bed then moves up and down the magnet.
Before your appointment
Due to the powerful magnet that is used in MRI, not all patients can be scanned such as patients with pacemakers, surgical clips, certain types of implants, or metal fragments (shrapnel) in their body. For this reason, you will be asked to complete a safety questionnaire.
We also try to avoid scanning patients during the first trimester of pregnancy (12-14 weeks) unless the scan is urgent and important.
Unless you are told otherwise, no special preparation is needed for your scan and you may continue to eat and drink as normal and take any prescribed medicine.
If you are at all concerned please contact the department before your scan appointment.
On arrival, you will be asked to complete the safety questionnaire. 9 Harley Street has a quiet waiting room with complimentary coffee, tea and soft drinks, newspapers and internet access to make your short wait more pleasant.
One of our Radiographers will then check your safety questionnaire answers with you, and will explain the procedure and answer any questions you may have.
You will then be asked to change into a hospital gown and will also be asked to remove all metallic objects such as jewellery, hair slides etc and possibly make-up (mascara contains metallic particles). We will take care of any valuables but cannot be responsible for loss or damage, so please try to keep these to a minimum.
The Radiographer will take you into the scanning room where you will be asked to lie on the bed. During the scan you will slowly move through the scanner. You will experience no discomfort but will hear loud, rhythmic noises. You may also be aware of a slight vibration, which is perfectly normal. We ask you, as a precaution, to wear ear protecting headphones during your scan. Alternatively you can listen to music during your scan, you are welcome to bring your own CD or MP3 player with you.
During the scan you will be asked to lie still to produce sharp images. Many patients find this quite relaxing and a number fall asleep. The radiographer operating the scanner can both see and hear you clearly throughout the procedure and can speak to you through an intercom. You will be given a buzzer to hold which you can use to summon attention.
Will I need an injection?
Sometimes, to gain extra information from the scans, it is necessary to be given an injection of contrast agent (it does not contain iodine). You will be asked about any allergies but these contrast agents are very safe and do not have any after effects.
How long will it take?
You can expect the scan to last between 30-60 minutes. Please give yourself plenty of time for your appointment.
After the examination
There should be no after effects and you may eat and drink as usual. Following the examination the images are processed and reviewed by a Consultant Radiologist who will provide your doctor with a report. You should then make a follow up appointment with your doctor to discuss these results.