Magnetic resonance imaging -- usually known as an MRI exam -- produces extremely detailed images of the body without side effects. It is noninvasive, uses no radiation and provides superior imaging in all parts of the body. The procedure is painless and harmless.
How it Works
Magnetic resonance uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures of muscles, fat and internal organs. It is able to look "through" bones to examine soft tissue without using X-ray. A computer translates the magnetic radio waves into pictures that are read by a radiologist.
How to Prepare for Your Test
In some instances you may wear a hospital gown. For other procedures, you may wear your regular clothing. You will lie down on a table for the procedure so wear loose-fitting, comfortable clothes. Because metal or electronic items such as jewelry, piercings, watches, hearing aids, pens or belt buckles can interfere with the magnetic field do not bring them into the MRI unit.
Guidelines about eating and drinking before an MRI vary with the procedure. Unless you are told otherwise, eat and drink as you normally would, and take any prescriptions.
Some MRI examinations may require you to swallow contrast material (dye) or receive an injection of contrast into your bloodstream. You will be asked if you have allergies or any kind of asthma. You will also be asked if you have any serious health problems. Severe kidney disease may prevent you from having an MRI with contrast material.
Because an MRI uses a powerful magnetic field the test may not be appropriate for those who have had brain, ear or eye surgeries, those who are pregnant or might be pregnant or individuals having:
- Cochlear implants
- Metal pins, surgical staples, screws or plates
- Foreign metal object in the eye
- Aneurysm clips or stents
- Implanted drug infusion devices
- Intrauterine devices (IUDs)
- Shrapnel or bullet wounds
What the Procedure Is Like
Parkland’s MRI unit is a short-bore MRI that has a wider opening with less claustrophobic effects. In fact, in 60 percent of the procedures, the patient's head is outside of the machine. Once in the machine, there is about a foot of headroom. This is helpful for larger patients or those who are claustrophobic. The short-bore MRIs also are wide enough to allow patients with bad backs to bend their knees.
A technologist helps you on the screening table and makes you comfortable. Once the test begins, you need to remain still until it is over. The technologist goes to another room, but watches you through a window and remains in contact with you through an intercom. You are given a call button to summon the technologist at any time.
A device called a coil may be placed over or wrapped around the area to be scanned. You will then be positioned under the magnet.
If a contrast material is used in the test, a nurse or technologist will insert an intravenous line into a vein in your hand or arm. When administered intravenously, the contrast material may make you feel a hot flushed sensation for a few seconds.
You can request your favorite style of music to be played during your test, you can bring a CD to listen to through our ear phones, or you can request ear plugs.
MRI tests usually include multiple runs, some of which may last several minutes. The entire procedure is usually completed in less time with a short-bore MRI.
If You Have Claustrophobia
If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your physician for a prescription for a mild sedative. Some machines, such as the short-bore MRI offered at Parkland Health Center, are more suitable for people with this condition.
When Your Test Is Completed
With our advanced software, your physician has access to your image and all of your clinical information almost immediately. Your images are read by a radiologist, and your physician will have a full report within 24-48 hours. Your physician will contact you regarding the results.
MRI Tests for Children
It can be hard for children to keep still when they are not feeling well. Movement during an exam lowers image quality and can cause MRI tests to take longer. This can lead to even more stress for children. Dress the child in comfortable clothing without metal parts, such as zippers or snaps. Bring along the child's favorite toy or blanket to provide some reassurance. More detailed information will be provided if your child is scheduled for a sedation exam.