Magnetic resonance imaging (MRI) is a test that produces very clear pictures, or images, of the human body without the use of x-rays. MRI uses a large magnet, radio waves and a computer to produce these images. Your physician may also order an MRA (Magnetic Resonance Angiography). This exam is used to evaluate vascular abnormalities, such as vascular malformations, aneurysms, vertebrovascular and carotid atherosclerosis, thrombosis and dissection. It also lets your doctor see internal organs, blood vessels, muscles, joints, tumors, areas of infection, and more without x-rays, surgery, or pain. MRI is very safe; in fact, it makes use of natural forces and has no known harmful effects. It’s important to know that an MRI will not expose you to any radiation.
What is an MRI?
Magnetic Resonance Imaging (MRI) is a diagnostic imaging technology that uses a strong magnet and radiofrequency waves to produce pictures or "images" of your internal organs and structures. Because MRI allows your doctor to see inside your body from any angle with great clarity, it is giving doctors a wealth of information more quickly and in many cases, more economically than past tests and exploratory surgeries.
Magnets and Metal Don't Mix
When you first enter the MR clinic, you must let the staff and technologist know if you have a pacemaker, surgical clips, prosthesis, metal implants or any other metal objects in your body. Some implants (e.g., a pacemaker) may be affected by an MR examination. The clinic personnel will then determine whether or not you should proceed with the MR examination.
Any metal materials that might be affected or attracted by the powerful magnet used for MR imaging should be left at home or can be secured in a locked cabinet in your private changing area. This list includes your watch, coins, keys, bobby pins, credit cards, pocketknives, etc. You should also be certain that you are reasonably clean of metal flakes or slivers on your skin, as found in some eye make-up or as a result of working around metal finishing or grinding equipment.
Your MRI Exam
Your MR exam is really quite simple. With the assistance of an MR technologist, you will be positioned on a padded table. Because it is essential that you remain as still as possible. The padded table will move smoothly into the magnet opening and your exam will begin. The technician is able to speak with you at all times during the exam.
During your MRI exam you won't feel anything. The only thing you'll notice is a knocking or buzzing sound that occurs as the images are being taken. You will be provided with earplugs to wear during the scan, or an MR compatible audio headset may be available to minimize the noise. The length of your exam is dependent on the type of study being done but will generally last from 45 minutes to over an hour.
An intercom and mirror arrangement in the system allows the MR staff to see and hear you throughout the exam. If you become uncomfortable at any point, you can alert the technician. The MR staff will be right there to assist you. Once the exam is completed, your technologist will bring you back to the preparation room to collect your belongings. And that's all there is to it!
For more information on DIagnostic Imaging, download "What You Need to Know about Your MRI."