What is MRI?
Magnetic Resonance Imaging (MRI) provides physicians a method of seeing your internal body structures without using x rays.
This technology enables physicians to detect developing disease or abnormalities earlier than ever before. Basically MRI involves a powerful but harmless magnetic field and radiowaves like the kind that transmit your favorite FM music.
The combination of radiowaves and a magnetic field produces very clear images of body structures such as the brain, the spine, and other vital organs.
What kind of machines are used to perform MRI?
Your scan will be performed in a room containing a big MRI machine that many doctors call "the magnet" The MRI unit looks like a large box with an open-ended tunnel running thought the middle. Many different kinds are in use, but they all work in the same way. You will be asked to lie on a comfortable, padded table that is gently moved into the opening of the magnet where the scanning is performed.
Sometimes a "coil" which is really just a special radio receiver, will be placed around the body part being scanned (your head, or knee, or stomach, etc.). The data from the scan is fed into computers which turn it into very clear pictures that the radiologist will use to make a diagnosis:
Does MRI hurt?
No! MRI itself is a painless procedure that has virtually no known side effects. To date, millions of patients have experienced MRI and the procedure has been proved to be extremely safe. MRI uses harmless radiowaves and magnetization instead of X-rays.
Is MRI for everybody?
While the great majority of people can undergo an MRI examination with no problems, some cannot. The radiologist or staff at the MRI center will probably ask you questions like the following:
§ Do you weigh more than 300 pounds?
§ Can you lie flat for an extended period of time?
§ Do you suffer from claustrophobia?
§ Are you pregnant?
Also, since the MRI scan involves the use of a powerful magnet it is not surprising that you will be asked the following kinds of questions:
§ Do you have implanted devices such as a cardiac pacemaker, a cerebral aneurysm clip, a neurostimulator, or a hearing aid?
§ Do you have any metal shrapnel in your body or any metal fragments in your eyes?
Remember that the questioning process is a two-way street. After providing all of the necessary information, feel free to air any concerns you may have about the upcoming examination: Don't be afraid to ask! Radiologist and technologists expect questions and part of their job is answering them.
What happens the day of the examination?
You should allow about two hours for your MRI examination, although most scans take an hour or less. Unless your doctor tells you otherwise, you can eat normally the day of the examination. Don't wear any make-up, since some brands contain metallic components.
When you arrive at the hospital, you will be asked to put on a patient gown and to remove all personal possessions such as your watch,wallet and car keys or metallic items such as dentures, pins, etc.
It's very important not to take anything that could be affected by a magnet into the examining room. For example, the information on your credit cards could be erased if you had them in your pocket during the examination!
What happens during the actual examination?
You will be escorted into the room containing the "magnet" by a technologist. You'll be asked to lie down on a padded table.
Then the technologist will position you inside the magnet so that the appropriate part of your body is ready to be scanned.
During the examination, you will be able to talk with the people conducting the examination by means of an intercom and they will be able to watch you through a glass window.
You may hear very loud clanking and thumping sounds that the machine makes as the technologists adjust the radio frequencies and other controls. These sounds are completely normal, but since they can be loud, some centers may even supply ear plugs for patients. Sometimes, a radiologist, nurse, or technologist may come into the scanning room to inject a fluid called an "enhancement agent." Don't be concerned if you are told you will be receiving this fluid. It may help your radiologist interpret the pictures taken during the examination.
All you have to do during the examination is lie as still as possible. Very active children may require some relaxing medication (sedation) prior to the examination to help them stay still.
When do I find out the results?
Once the examination is completed, the MRI pictures will be studies by the radiologist and compared to any previous MRI pictures of this same area you have had taken previously. A written report of the radiologist's findings will be forwarded to your physician either by fax or through the mail. Please allow a few days before contacting your physician for the results. After this procedure you may resume normal activities.