Magnetic Resonance Imaging (MRI) is a way of obtaining very detailed images of organs and tissues throughout the body without the need for x-rays. It uses a magnetic field, radio waves and a computer to create detailed images of structures inside the body. For this procedure, the patient is placed within the MR scanner-typically a large, tunnel or doughnut-shaped magnet at both ends. The magnetic field aligns atomic particles called protons that are present in most of the body's tissues. Radio waves then cause these particles to produce signals that are picked up by a receiver within the MR scanner. The signals are specially characterized using a changing magnetic field, and computer processor to create very sharp images of tissues as "slices" that can be viewed in any orientation.
X-rays are best for viewing bones. MRI creates images that help doctors see the difference between healthy and unhealthy tissue. Doctors use MRI to examine soft tissues like organs, muscle, cartilage, ligaments, and tendons in many parts of the body. This includes such areas as the brain, spine, breast, abdomen, pelvic region, and joints like the knees and elbows. The MRI image is one of the tools your doctor will use to make decisions about your medical care.
What happens after your scan?
Once your scan is complete, a board-certified radiologist, a physician who specializes in reading diagnostic images, interprets results from your MRI and sends a report to your doctor. Your doctor will discuss the results with you.
How should you prepare for your MRI?
Preparing for your MRI exam is easy. You can take your normal medication unless your doctor gives you special instructions. Bring your doctor's prescription and all of your insurance information to the exam. A member of the McLaren MRI staff will ask you a series of questions before your MRI exam. These questions screen for any implants or health conditions that might create a health risk or interfere with imaging. You may receive a gown to wear during your MRI exam and asked to remove any metal objects from you body such as jewelry, eyeglasses, hairpins and anything else containing metal. If you have any questions, call your doctor or McLaren MRI at Clarkston.
What should you expect during your MRI?
An MRI is an outpatient procedure. An MRI causes no pain, and the magnetic fields produce no known tissue damage of any kind. You will be able to communicate with the MRI technologist or radiologist at any time using an intercom system or by other means.
If you know you have any allergy, are taking prescription medications, or are a woman of childbearing age and think you may be pregnant, or are breast-feeding, tell the technologist prior to the procedure.
Specific Protocols:
- All jewelry and metal objects must be removed because of the magnet. Tell your physician and MRI technologist before the MRI exam if you have a pacemaker, defibrillator, brain aneurysm clip or other implanted devices.
- You will be asked to lie down on the scanning table. Once the MRI technologist has you positioned correctly, he or she will go into an adjoining room. Even though the technologist has left the scanning area, he or she can see you through a glass partition and communicate with you via a sound system that connects the two rooms.
- During the scanning process, you will hear a very loud knocking sound as the magnetic field is created and pulses of radio waves are sent from the scanner. Earplugs are given to help block the noise.
- An MRI usually takes 30-60 minutes.
Sometimes certain conditions can be difficult to see on an MRI image, so your physician may request that you receive an injection of a substance called "contrast media" to provide a vivid picture of the area being examined. Patients with normal kidneys will eliminate the contrast media within a few hours, but for patients with kidney problems it may take longer. Make sure you inform your doctor and the MRI technologist if you have or have ever had kidney problems so they can determine whether or not you can have a contrast agent with your MRI.