Magnetic Resonance Imaging provides detailed images of internal organs, bone and soft tissues. The scanner uses harmless low energy radio waves and a strong magnetic field to produce detailed images. No radiation is involved.
Because a magnetic field is used it is necessary for the staff to know about any metal objects e.g. artificial joints, surgical clips, pacemakers, cochlear implants and aneurysm clips. Staff will ask you to complete a comprehensive questionnaire related to any metal objects that may be in your body. It also asks about the possibility of metal fragments within your eyes from working with metal, as these fragments may move during the scan because of the magnetic field. If metal fragments are a possibility you will be asked to have an x-ray prior to your MRI appointment to rule them out.
MRI scanning is ideal for imaging muscles, soft tissue organs and vessels. It is also ideal for demonstrating spinal and joint problems.The scan is performed by a Medical Radiation Technologist (MRT) who has been specifically trained in MRI scanning. The images gathered are seen by a Consultant Radiologist with specialist training in interpreting MRI scans.MRI scans generally take 20-45 minutes per region of the body that we are imaging. You will be asked to lie completely still on a cushioned table and will be positioned within the scanner, depending upon the part of your body that is being scanned.
MRI images are highly sensitive to movement. It is very important to keep still during the scan, as this will improve the quality of the images we obtain. The best way to keep still is to try and be relaxed, lying comfortably as if you were dropping off to sleep.
The MRI scan itself is a painless procedure. Sometimes you may need a contrast injection. The contrast we use for MRI scans is considered very safe and is gadolinium based. The scanner will produce extremely loud knocking noises when it operates so you will be given either headphones or earplugs to wear. This is entirely normal.
Preparing for your examination: For most MRI examinations no preparation is required.Please eat and drink as normal and continue to take all of your regular medications unless we ask you otherwise.
- It is advisable to leave all jewellery and valuables at home as you will be requested to remove all of these for every examination.
- We ask you to arrive 15 minutes before your scan appointment time so we can take you through to a changing area. You will be asked to change into a gown that we provide. This will occur for all examinations.
Occasionally, claustrophobia is a problem. If there is concern about this possibility, please discuss this with your GP prior to your appointment as they may prescribe some oral sedation that you will be able to take prior to your scan. This will help to make it a more enjoyable experience for you and will enable us to obtain the best images possible.
MRI Equipment: To gain information we are required to place a “coil” over the area of your body that we are scanning. These are various shapes and sizes and in most cases will not touch you.
The MRI scanner is always open at both ends. There is two way communication possible via an intercom and an emergency ball if you have any concerns.
There is cool air flowing inside the scanner for your comfort as well as a light.
Following your examination: There are no side effects from having an MRI and unless you have taken an oral sedative from your GP or had an arthrogram you will be okay to drive home.
Results: Your results will be sent to your specialist and your GP within 24-48 hours. In some cases this may take a little longer depending on the complexity of your case.