A magnetic resonance imaging (MRI) scan is a common procedure around the world.
MRI uses a strong magnetic field and radio waves to create detailed images of the organs and tissues within the body.
Since its invention, doctors and researchers continue to refine MRI techniques to assist in medical procedures and research. The development of MRI revolutionized medicine.
Fast facts on MRI scanning
What is an MRI scan?
An MRI scan uses a large magnet, radio waves, and a computer to create a detailed, cross-sectional image of internal organs and structures. The scanner itself typically resembles a large tube with a table in the middle, allowing the patient to slide in. An MRI scan differs from CT scans and X-rays, as it does not use potentially harmful ionizing radiation.
The development of the MRI scan represents a huge milestone for the medical world. Doctors, scientists, and researchers are now able to examine the inside of the human body in high detail using a non-invasive tool.
The following are examples in which an MRI scanner would be used:
This list is by no means exhaustive. The use of MRI technology is always expanding in scope and use.
A person can listen to music in headphones to mask the loud and sometimes alarming sound of the MRI machine.
There is very little preparation required, if any, before an MRI scan.
On arrival at the hospital, doctors may ask the patient to change into a gown. As magnets are used, it is critical that no metal objects are present in the scanner. The doctor will ask the patient to remove any metal jewelry or accessories that might interfere with the machine.
A person will probably be unable to have an MRI if they have any metal inside their bodies, such as bullets, shrapnel, or other metallic foreign bodies. This can also include medical devices, such as cochlear implants, aneurysm clips, and pacemakers.
Individuals who are anxious or nervous about enclosed spaces should tell their doctor. Often they can be given medication prior to the MRI to help make the procedure more comfortable.
Patients will sometimes receive an injection of intravenous (IV) contrast liquid to improve the visibility of a particular tissue that is relevant to the scan.
The radiologist, a doctor who specializes in medical images, will then talk the individual through the MRI scanning process and answer any questions they may have about the procedure.
Once the patient has entered the scanning room, the doctor will help them onto the scanner table to lie down. Staff will ensure that they are as comfortable as possible by providing blankets or cushions.
Earplugs or headphones will be provided to block out the loud noises of the scanner. The latter is popular with children, as they can listen to music to calm any anxiety during the procedure.
During an MRI scan
Once in the scanner, the MRI technician will communicate with the patient via the intercom to make sure that they are comfortable. They will not start the scan until the patient is ready.
During the scan, it is vital to stay still. Any movement will disrupt the images, much like a camera trying to take a picture of a moving object. Loud clanging noises will come from the scanner. This is perfectly normal. Depending on the images, at times it may be necessary for the person to hold their breath.
If the patient feels uncomfortable during the procedure, they can speak to the MRI technician via the intercom and request that the scan be stopped.
After an MRI scan
After the scan, the radiologist will examine the images to check whether any more are required. If the radiologist is satisfied, the patient can go home.
The radiologist will prepare a report for the requesting doctor. Patients are usually asked to make an appointment with their doctor to discuss the results.
It is extremely rare that a patient will experience side effects from an MRI scan.
However, the contrast dye can cause nausea, headaches, and pain or burning at the point of injection in some people. Allergy to the contrast material is also seldom seen but possible, and can cause hives or itchy eyes. Notify the technician if any adverse reactions occur.
People who experience claustrophobia or feel uncomfortable in enclosed spaces sometimes express difficulties with undergoing an MRI scan.