Your MRI: What to Expect
You are about to have an MRI scan, and while you may familiar with the term, you may not be quite sure what to expect. Our staff at Mercy Medical Center-North Iowa is ready to answer your questions and assist you in any possible way - from completing paperwork to explaining the procedure. Let's begin with the basics.
MRI stands fro Magnetic Resonance Imaging. This is a safe and dynamic way for doctors to see inside the body and diagnose certain diseases. MRI does not use x-rays. Instead it uses a magnetic field and radio waves to create a very clear picture of structures inside your body. MRI uses sensitive equipment and specially designed computers to create images of the entire area being scanned. There is no radiation involved, and the procedure should not cause you any pain.
"Seeing" Inside Soft Tissues
While x-rays are best for viewing bones, MRI creates pictures that can distinguish differences between healthy and unhealthy tissue. Doctors use MRI to examine soft tissues such as organs, muscle, cartilage, ligaments, and tendons in many parts of the body. This includes looking at the brain, spinal column, breast, abdomen, pelvic region, and joints like knees and elbows. The resulting MRI images are another tool doctors use to make decisions about your medical care. MRI has been called one of the most significant advances in modern medicine.
The Scanning Procedure
The actual examination takes place in a room that houses the MRI equipment. You will be asked to lie down on a scanning table. Earplugs are mandatory for the examination because the imaging process is noisy and loud. The MRI scanner is a four-foot long tube. Depending on what body area is being scanned, you may enter the machine head-first or feet-first. Alert your physician if you are claustrophobic. Once you are positioned comfortably and enter the machine, the MRI technologist will move to an adjoining room. The technologist will check to check that you both can communicate clearly through the sound system joining the two rooms. The technologist will also be able to see you through a window near the computer equipment.
While the scanner is operating, you just relax and lie still. MRI imaging is very sensitive to motion artifact. Although it is not harmful to you if sequences are repeated, it does add more time to your examination. It may be helpful to close your eyes, although not required. At times, you may hear a rhythmic knocking sound within the machine that pauses and then repeats. This is the sound of the MRI scanner generating a harmless magnetic field that helps create an image. You may also feel vibrations on your skin that coincide with the noises. This is normal and should not be painful. Most exams take between 30 and 45 minutes. You'll be told ahead of time exactly how long your scan is expected to take.
Contrast for a Clearer Picture
Sometimes abnormalities can be difficult to see on an MRI image and your doctor may request that you receive an injection of a contrast agent to provide a clearer picture of the area being examined. Sometimes this material is referred to as a dye. It can help clarify structures in the central nervous system, head, neck, and body. The MRI contrast agent is administered through an IV. The contrast does not interfere with lab testing or most other contrast agents. However, if you are also scheduled for a PET scan, please make sure that the PET scan is done prior to the MRI. Also, please alert the MRI technologist if you are diabetic and/or have limited kidney function. This may affect the use of MRI contrast. If you have an additional procedure the same day of your MRI exam that involves an IV placement, please alert the medical staff of your appointment. Staff can check as to whether you they should leave the IV in for the additional test.
Once the scan has been completed, a radiologist will be able to view a series of images of the area examined. The images show the different structures of your body from the front, side, and top of your body in great detail. After the radiologist interprets your images, a report will be typed up and faxed to your referring physician once it is signed as the final copy. Ordinarily this is finished within 24 to 48 hours of your MRI examination.
Although there are generally no special preparations necessary before an MRI examination, there are some details to keep in mind. Because metal interferes with the MRI equipment, you will not be allowed to wear watches, jewelry, and most anything else containing metal into the magnet room. All body piercings must be removed prior to the MRI exam. Also, no keys, coins, credit cards, dentures with metal components, hearing aids, medical alert devices, or cell phones are allowed in the MRI suite. Even some cosmetics contain metal so be mindful of the makeup you where on the day of your MRI. Be sure to let your doctor know if you have a pacemaker or cardiac defibrillator, aneurysm clip, stapes ear implant, neurostimulation system, programmable shunt, tissue expander, or other metallic implant before you come for your MRI. Also alert your physician if you have ever had metal in your eye(s). X-rays of your eye will be required before entering the magnet room if you have never had an MRI at our facility. This is required no matter how long ago the injury was or if a doctor removed the fragments. Some implanted items need to be investigated before you will be allowed to enter the magnetic field. A thorough checklist will be completed upon your arrival for the MRI to make sure you are safe to enter the magnet room. These requirements are for your safety and ours.
There are only a two body regions that require a specific preparation before imaging. If you are have an abdominal (liver, pancreas, kidney, etc.) or pelvis study, we request you do not eat or drink at least 4 hours prior to your scheduled scan time. This helps keep your GI tract empty for the purpose of better imaging. If you are diabetic and concerned about your blood sugars, please alert the technologist of your concerns.
Please alert your physician if you are claustrophobic. They should be able to write you a prescription for sedation medication to help you get through the MRI exam. We request that you bring your medication with you so you can take it when the MRI staff instructs you. You will be asked to arrive 1 hour prior to your schedules exam time in order for the medication to have time to take effect. We also request that you bring a driver since medications affect people in different ways. You will be asked to have nothing to eat or drink 4 hours prior to taking the medication. The medication will take effect faster on an empty stomach. Again, if you are diabetic, please alert the MRI technologist to any concerns. The medication should help you relax and ease anxiety about the MRI examination.
You may need to have x-rays to correlate with your MRI exam. If this is the case, you will be asked to arrive 1 hour prior to your scheduled MRI scan to allow for the time needed for the x-rays. The x-rays will be done at Radiologists of North Iowa, P.C. unless you specify otherwise. Please be mindful of what your insurance company allows for coverage of payment at certain facilities.
If your child will be having an MRI exam under sedation, be aware that two adults are required to accompany the child home after the scan and recovery period. You will be asked to arrive 2 hours prior to the MRI scheduled scan time in order to have an IV started in the pediatric unit. There will also be a recovery period dependent on how fast your child awakens after the MRI in the same pediatric unit. It's a good idea to plan to be here 4 to 6 hours on the day of the exam. You will be called with additional instructions and questions the night before your child's MRI exam by the pediatric nursing staff.
MRI: An Important Diagnostic Tool
Millions of people from young children to the elderly have had MRI examinations. MRI is an important diagnostic tool helping the medical community make better decisions about your health care.
Please do not hesitate to contact us if you have any questions or concerns involving your upcoming MRI examination. We are happy to help you in any way possible.