What is a MRI scan?
Magnetic Resonance Imaging (MRI) is a safe, non-invasive diagnostic medical imaging technique which uses magnetic fields, radio waves and sophisticated computer programs to generate highly sophisticated images of the human body.
MRIs produce cross-sectional pictures through every part of the body. The information from the scanner passes to a computer that produces a picture of your internal structure.
MRI can help doctors to diagnose many medical conditions and it is particularly useful for:
- Injuries and diseases of joints such as the knee, shoulder, ankle and wrist.
- Neurological problems, including diseases affecting the brain and spinal cord.
- Problems affecting the eyes and inner ear.
- General medical conditions, whereby MRI enables abdominal structures to be clearly visualised, e.g. liver, kidneys and pancreas.
- Imaging of blood vessels.
What does this involve?
MRI procedures can take from 20 to 90 minutes. It takes 20 minutes for each area of your body being imaged.
Before the MRI you will be asked a series of questions to check that it is safe for you. It will be necessary to change out of any clothing that has metal clips, fasteners or zips or we can provide you with a gown to wear. You will also be asked to remove your watch, any jewellery, credit cards and loose change which will be kept safe in a private locker.
It is not necessary to remove your wedding ring. A small team including a radiolographer, radiologist and an assistant will care for you. The radiographer will carry out the scan.
They will assist you to lie down on the couch top outside the scanner and make you comfortable - the couch top will then move you into the MRI machine.
The radiographer will leave the room before the scan begins, but can see you at all times from the control room. You will also be provided with a buzzer that you can press at any time which will alert the radiographers should you feel uncomfortable.
The scanner will make a loud knocking sound as the images are being taken so you will be provided with ear defenders.
You will need to lie as still as possible when instructed by the radiographer through the intercom so the best quality images can be obtained.
The scan will not be painful nor will you feel any discomfort of after effects.
When will I recover?
MRI scans are done as outpatient appointments and you are able to go home immediately afterwards.
What risks should I know about?
Clinical experience to date has shown MRI to be a safe and effective clinical investigation and most people are suitable for an MRI scan. However, for patients' safety, we need to carefully screen all patients before they have a scan by asking them specific questions.
Patients who have a history of the following are potentially at risk:
- A cardiac pacemaker
- An artificial heart valve
- A neuro stimulator
- Had previous brain surgery
- A cochlear implant in your ear
- Had any surgery involving metal implants within the last 6 weeks
- Ever had an ANY accident with METAL entering their EYE(s)
- Are pregnant or breast feeding (if you are or might be pregnant you must make sure the doctor referring you or a member of staff in the Radiology Department knows as soon as possible. MR scans may not be advisable in early pregnancy, unless there are special circumstances)