What Is Magnetic Resonance Imaging?
Magnetic resonance imaging, or MRI, is an advanced method of generating clear images of the body without the use of X-rays. MRI uses a powerful, harmless magnetic field and radio waves to produce detailed images of your body structure, such as your brain, spine, extremities and other organs.
What Are Some Common Uses of MRI?
Imaging of the Musculoskeletal System
MRI is often used to study your bones and joints: the knee, ankle, foot, shoulder, elbow, wrist and hand. MRI is also a highly accurate way to evaluate soft-tissue structures such as tendons and ligaments. Even subtle injuries are easily detected.
In addition, MRI is used for the diagnosis of spinal problems, including disk herniation, spinal stenosis and spinal tumors.
Imaging of the Heart
MRI of the heart, aorta, coronary arteries and blood vessels is a tool for diagnosing coronary artery disease and other heart problems. Doctors can examine the size and thickness of the chambers of the heart and determine the extent of damage caused by a heart attack or heart disease.
Imaging of Cancer and Organ Functional Disorders
Organs of the chest and abdomen such as the liver, lungs, kidney and other abdominal organs can be examined in great detail with MRI. This aids in the diagnosis and evaluation of tumors and functional disorders.
Imaging of Breast Cancer
In the early diagnosis of breast cancer, MRI is an alternative to traditional X-ray mammography. Furthermore, because no radiation exposure is involved, MRI is often used for examination of the male and female reproductive systems.
Preparing for Your MRI
Before your MRI exam, remove all accessories, including hair pins, jewelry, eyeglasses, hearing aids, wigs and dentures. When you arrive in the Radiology department, you will fill out a screening sheet to check for the presence of any of these items.
The MRI technologist will ask you to remove all materials that might be affected or attracted by the powerful magnet, such as watches, coins, keys, bobby pins, pocket knives and other items. During the exam, these metal objects may interfere with the magnetic field, affecting the quality of the MRI images taken.
Notify your technologist if you have:
- Heart pacemaker (or artificial heart valve), defibrillator or artificial heart value
- Intrauterine device (IUD)
- Metal plates, pins, screws or surgical staples in your body
- Prosthetic joints such as a hip or knee
- Tattoos and permanent makeup
- A bullet or shrapnel in your body, or if you have ever worked with metal
Also let your technologist know:
- If you might be pregnant or suspect you may be pregnant
- If you are claustrophobic – a sedative may be administered if necessary
- The technologist will ask you to lie down on a cushioned table that automatically moves into the center of the magnet after you have been comfortably positioned.
- The technologist will leave the magnet room, but he or she will be in constant contact throughout the exam. The magnet makes a knocking sound as images are taken, but earplugs and headphones will be provided for your comfort. Since MRI is a noninvasive procedure, it’s painless.
- Relax – even take a nap.
- Lie as still as possible. Moving during the procedure may require repeating parts of the exam.
- The doctor may ask for a contrast agent to be administered so the machine can visualize a certain part of your body. If this is the case, you may have an intravenous (IV) line inserted. If a contrast injection is needed, you may feel a cool sensation during the injection, and there may be some discomfort at the injection site afterward. Depending on the area of the body being scanned, the exam will last 30 to 60 minutes.