Magnetic Resonance Imaging, or MRI, has greatly improved the accuracy of diagnostic imaging, particularly in structures such as the liver, brain and spinal cord. Patients are not exposed to X-rays with MRI testing; instead, images are created with the use of strong magnetic fields, radio waves and a sophisticated computer system.|
Another revolution in Medical Imaging during the past 20 years is Magnetic Resonance Imaging, or MRI. MRI has greatly improved the accuracy of diagnostic imaging, particularly in structures such as the liver, brain and spinal cord.
A great advantage of MRI is that the patient is not exposed to X-rays. Instead, the images are created with the use of strong magnetic fields, radio waves and a sophisticated computer system. MRI allows the radiologist to see precise images of soft tissue structures and organs, including the brain, spinal cord, nerves, muscles, cartilage and ligaments. MRI is used to diagnose many conditions, including:
Infections of the brain, spine or joints
Strokes in their earliest stages
MRI can also visualize:
Preparing for this test: Unless you are told otherwise, take all of your regular medications and follow your normal diet. For some scans, you must wear a patient gown. Private dressing rooms are available. All removable metallic objects must be left outside the scanning room, including removable hearing aids, dentures and other prosthetic devices. Please tell your doctor and the MRI staff if you have any metal in your body that cannot be removed, including: pacemakers, implanted insulin pumps, aneurysm clips, vascular coils and filters, heart valves, ear implants, surgical staples and wires, shrapnel, bone or joint replacements, metal plates, rods, pins or screws, contraceptive diaphragms or coils, penile implants, and permanent dentures. In most cases, you can be scanned even though you have metal implants. Nevertheless, the radiologist and MRI staff must be aware of them. Also, tell a member of the staff if you are pregnant or if there is a possibility you are pregnant.
The Actual Test: An MRI is a comfortable and easy exam. You will be positioned on a table with the part of your body being scanned placed at the center of the tunnel-like portion of the machine. If you are claustrophobic, please discuss this with your doctor. While the scan is in progress, you will hear a variety of pinging and thumping noises that stop and start at different times. The test can take anywhere from 30 to 90 minutes, depending on the number of images that need to be acquired.
For some tests, a special contrast material is injected into an arm vein when imaging certain parts of the body. MRI contrast, called Gadolinium, does not contain iodine and is different from x-ray dye. The contrast is safe and has very few, if any, side effects.