About Magnetic Resonance Image (MRI)
What Is An MRI? Why MRI? How Should I Prepare For The MRI Procedure? What Happens During The MRI Exam? Who Can Have An MRI Scan? What Should I Expect Afterwards?
What Is An MRI?
An MRI scan is used to help diagnose a wide variety of medical conditions that affect soft tissue structures and organs in the body. Common conditions consist of joint injuries or pain in joints, diagnosis of masses in tissue, spinal injuries and related conditions with the spine.
Depending on the area, it may be necessary to inject a dye so the tissues show up more clearly. This dye is completely different than dye used in other studies. Reactions to MRI dye are extremely rare.
The MRI uses radio waves and a magnetic field to provide detailed images of particular parts of the body. There is no exposure to x-ray radiation with an MRI.
Why MRI?
Generally speaking, MRI provides more detailed images than other scans, particularly of the brain and circulatory system, and is better at showing differences between various types of tissue in spine and joints. It is the best radiology study for ligaments and cartilage of the joints. It may compliment CT in clarifying abnormalities of the liver, kidneys, and other 'solid' organs. It is great for seeing if bones are infected. Unlike other scans, MRI images can be taken from almost any angle without moving the person around.
How Should I Prepare For The MRI Procedure?
In most cases, no special diet is needed and no special preparations are necessary before having an MRI scan, though people having pelvic or abdominal scans may be given special instructions for eating and drinking beforehand.
You should inform your physician of all medications you are taking prior to your procedure. You will not be allowed to wear anything metallic during the exam, so it is best to leave watches, jewelry, or anything else containing metal at home. Parents who wish to stay with their child need to follow these guidelines as well.
Generally, a brief medical history is taken, along with minimal screening paperwork the day of your exam. When you arrive for your MRI, the technologist will discuss any concerns or questions you may have prior to beginning the procedure.
What Happens During The MRI Exam?
You begin by lying down on a comfortable table. Although the technologist does not remain in the room with you, they keep in close contact with you through an intercom and observe you throughout the procedure. There are two primary types of MRI machines, one is a traditional core machine that resembles a large tube you move through while you are being scanned. The other is called an open MRI.
While the scanner is operating, you experience humming and thumping sounds from the scanner. These sounds are completely normal and not something to be concerned about.
The majority of MRI scans take between 30 to 45 minutes, although some may take as long as 60 minutes. The most important thing for you to do while having your MRI is to relax and lie as still as possible. Movement can blur the picture and may cause repeat scanning of some of the images, which will result in a longer scan.
For some procedures, an injection of a contrast agent or “dye” is given to provide a clearer picture of the area being examined. Most commonly this is required for spinal scans, if you have had prior surgery on your spine, or if the MRI exam was ordered to determine a mass in the tissue or cancer. If a dye injection is needed, it is during the scan, usually into a small vein in the back of the hand.
Who Can Have An MRI Scan?
You may have an MRI even if you have an artificial joint, coronary bypass, IVC filter, cardiac stents, surgical staples, or screws in bones from previous orthopedic surgery (if healed). The magnetic field attracts metal objects, so is not suitable for people with certain metal implants in their body, including:
Heart pacemaker
Some (not all) metal prosthetic heart valves
Cochlear implants
Brain aneurysm clips
People who have had tiny pieces of metal in their eyes from accidents are also unsuitable for MRI.
What Should I Expect Afterwards?
Once the examination is over, that's it! You're done. The pictures taken by the MRI scanner will then be interpreted by a board-certified radiologist, and the results sent to your doctor who ordered the MRI.
