The magnetic resonance imaging (MRI) scanner gives detailed images of the soft tissues inside the body. It uses the property of nuclear magnetic resonance to image nuclei of atoms inside the body. Powerful computer software is used to generate detailed cross-sectional pictures of the soft tissues inside the body, which can be used to diagnose a wide range of medical conditions.
How does MRI work?
An MRI scanner is a tube, surrounded by a large, powerful magnet, in which the patient lies. The magnetic field causes nuclei within atoms in the body to produce a rotating magnetic field that is detectable by the scanner; this information is recorded and computer software generates a detailed image of the body. Unlike CT, MRI does not use ionizing radiation.
What does an MRI scan involve?
On the day of your scan you might have to drink some liquid that contains contrast (visible on the scan). You might need a cannula (small plastic tube) placed into a vein to enable the radiographer to give you intravenous contrast. The scan itself is painless and takes place in a tube-shaped machine. People with claustrophobia may have problems with the procedure and should discuss this with their specialist before the scan. To enable the machine to take images, you lie on your back on a table that moves into the scanner. During the scanning process, try to relax and lie still so that the MRI scanner can take accurate images. The whole scanning process will take between 15 minutes and one hour, depending on the different angles and number of pictures needed.
MRI scan aftercare
Once your MRI scan is complete, you will be able to go home and return to normal activities immediately. The images are put together on the computer and then analyzed in detail by the radiologist (Consultant with expertise in radiology). The report will be sent to your Consultant who will then be able to discuss the findings with you.
Our team at the Birmingham Colorectal Clinic have very close working relationships with the radiologists who report CT scans. This is important as scans are often more accurate when there is good clinical information available to the radiologist.