Magnetic Resonance Imaging (MRI)

Peer Review Status: Internally Peer Reviewed
First Published: 1998
Last Revised: March 2004

What is MRI?

MRI is a painless technology used to view inside the body without using X-rays. It can produce two- or three-dimensional images using a large magnet, radiowaves, and a computer. The magnetic fields MRI uses are not known to be harmful and are painless.

Preparing for an MRI Exam?

At Home

1. Eat normally unless you have been instructed differently by your physician. Children and infants requiring sedation should not eat or drink approximately four hours prior to the MRI exam.
2. Take any medication as usual.
3. Bring a book, magazine, or something else to do while you wait for your exam.

1. You will be asked your medical history.
2. You will be told about your exam, then asked to sign a consent form.
3. You will be asked to remove objects such as jewelry, hairpins, glasses, wig (if it has metal), hearing aids, and nonpermanent dentures. You will also empty your pockets of all objects.
4. You may be asked to change into a hospital gown.

You will be positioned as comfortably as possible by the MRI technologist. The MRI examination table will slide into the magnet. The magnet may be fairly close to your face (within a few inches), depending on the type of exam you are having.

During the exam, you do not feel anything, but you will hear an intermittent knocking noise that may change in the frequency pattern of knocking. When the exam is finished, the images will be reviewed. If more images are needed, they will be obtained as soon as possible. You will be informed when you may leave the MRI center.

Restrictions

You will not be able to have an MRI examination if you have the following:

• Pacemakers
• Neurostimulators (Tens-Units)
• Ear implants
• Any metal clips in the eyes

Considerations

Please notify the MRI Center personnel and your physician if you are pregnant. Pregnant women may be examined by MRI in certain critical cases.

Fillings in your teeth, dental braces, and permanent bridges may cause some distortion of the MR image around the mouth area, but will not cause harm to you or the MRI equipment.

Total examination time usually ranges from 40 to 90 minutes.

It is very important that you hold very still for your MRI examination. If you feel this may be a problem, please inform your physician.

There are some insurance companies that do not yet reimburse for the MRI procedure. You may wish to contact your insurance provider to verify your coverage.

Do you have any questions? Feel free to ask your physician or an MRI professional.

See related Patient Textbooks about Radiology.

See related Patient Topics Diagnostic Imaging, General, Procedures and Therapies or Radiology.

See related Provider Textbooks about Radiology.

See related Provider Topics Diagnostic Imaging, General, Procedures and Therapies or Radiology.

All contents copyright © 1992-2004 the Author(s) and The University of Iowa. All rights reserved.

http://www.vh.org/adult/patient/radiology/magneticresonanceimaging/index.html