Magnetic resonance imaging (MRI) uses radiofrequency waves and a strong magnetic field rather than x-rays to provide remarkably clear and detailed pictures of internal organs and tissues. The technique has proven very valuable for the diagnosis of a broad range of pathologic conditions in all parts of the body including cancer, heart and vascular disease, stroke, and joint and musculoskeletal disorders. MRI requires specialized equipment and expertise and allows evaluation of body structures that may not be as visible with other imaging methods, particularly neurological and orthopedic anatomy.
Because MRI can give such clear pictures of soft-tissue structures near and around bones, it is the most sensitive exam for spinal and joint problems. MRI is widely used to diagnose sports-related injuries, especially those affecting the knee, shoulder, hip, elbow and wrist. The images allow the physician to see even very small tears and injuries to ligaments and muscles.
Organs of the chest and abdomen—including the lungs, liver, kidney, spleen, pancreas and abdominal vessels—can also be examined in high detail with MRI, enabling the diagnosis and evaluation of tumors and functional disorders. MRI is growing in popularity as an adjunct to traditional mammography in the diagnosis and staging of breast cancer. Because no radiation exposure is involved, MRI is often an effective diagnostic tool for examination of the male and female reproductive systems, pelvis and hips and the bladder.
Will my insurance pay for an MRI? Most insurance companies require pre-authorization for an MRI exam. This means that your physician must call your insurance company in advance and obtain authorization number to assure that they will pay for the test. For specific information about insurance coverage or for payment questions, please contact your insurance company directly.
What happens during the procedure? During the MRI exam, you will be lying on a firm table. The technologist will position you on the table and then move the table to the center of the MRI machine. The inside of the machine is like a giant tunnel that is well lit and open on each end. The MRI makes a loud knocking noise while we take the image. For your comfort, you will be given ear plugs or ear phones to listen to music during the exam. The test takes approximately one hour. When the test is finished, you are free to go. The Radiologist will interpret the pictures and send a report to your physician.
Does the MRI exam require any needle sticks or injections? The Radiologist is the physician responsible for interpreting the MRI pictures and he/she also determines whether or not you need to be given an MRI contrast injection during your test. When needed to help make a diagnosis, an MRI contrast agent is given to improve the quality of certain images. MRI contrast reactions are rare. If your exam requires the use of an MRI contrast agent, the technologist or nurse will start an IV before or during the exam and administer the contrast.
How do I prepare to have this exam? Because we use a large magnet in the MRI, no metallic objects or mechanical devices can enter the imaging room. You may want to keep this in mind when deciding what to wear to your MRI appointment. Below is a list of suggestions to help you prepare.
Clothing: Wear something light weight and comfortable that is easy to take on and off. Avoid wearing clothing that has a lot of metal snaps, zippers or hooks.
Jewelry: All metal jewelry and watches must be removed.
Hair products: Many hair products, such as "Topik" to cover hair loss, or attachable hair weaves contain magnetic particles, and they must be removed.
Hair accessories: Any hair clips, ties, or pins that are made of metal or have metal parts on them must be removed.
Make-up: Because some make up, particularly mascara, is made with a metallic base, it is best not to wear much make up the day of your appointment.
Dental devices: If you wear dentures, or partial dental plates, they must be removed.
Medication & diet: You may continue to take any routine medications prescribed by your physician and there are no dietary restrictions unless you are scheduled to receive medication for claustrophobia, pain, or general anesthesia.
Special considerations: Because we use a strong magnet in the MRI, patients who have pacemakers cannot have an MRI exam. You will be asked to complete an MRI Patient Screening form prior to your exam. Additional information or testing may be needed prior to your MRI exam to ensure that it is safe for you to have this test:
- if you have any other implanted medical devices such as cochlear implants, penile implants, aneurysm clips, artificial heart valves, or recent cardiac stent
- or if you have metal shavings or gunshot shrapnel in the face or eye