Before Your Test
Before you schedule an MRI, tell your doctor if you think your might be pregnant or if you are breastfeeding. Your doctor may recommend choosing an alternative exam or postponing the MRI. It is also important to discuss any kidney or liver problems with your doctor and the technologist, because concerns with these organs may change the way the test is conducted.
Before an MRI exam, you may eat normally and continue to take your usual medications, unless otherwise instructed, however, for an abdominal or pelvic MRIyou must fast (no food or drink) for six hours prior to your exam. You will be asked to change into a gown and to remove any jewelry, hairpins, eyeglasses, watches, dentures, hearing aids and underwire bras.
During Your Test
The MRI machine looks like a large tube with both ends open, and you will be asked to lie down on a table that moves through the machine. A technologist monitors you from another room, and is in contact with you using an intercom system. The MRI creates a strong magnetic field around you, and radio waves are directed at your body. The procedure is painless, and you will not feel the magnetic field or radio waves. There are no moving parts around you. During the test, the internal part of the magnet makes knocking, thumping and other noises. Earplugs or earmuffs are provided to help block the noise. If you are worried about feeling claustrophobic inside the machine, talk to your doctor ahead of time. You may require a sedative before the scan. You must hold very still because movement can blur the resulting images.
In some cases, a contrast solution, typically gadolinium may be injected through an intravenous (IV) line into a vein in your hand or arm. The contrast material enhances the appearance of certain details. The solution used for MRIs is less likely to cause an allergic reaction than the one used for CT scans.
Be aware that an MRI test will take thirty minutes to one hour or more, so please plan your transportation or other appointments accordingly.
After Your Test
If you have not been sedated, you may resume your usual activities immediately after the scan.
The images are analyzed by a radiologist who has received specialized training in interpreting MRI scans. The results are provided to your physician who will then share them with you and discuss any important findings and next steps.
When you lie inside an MRI machine, the magnetic field temporarily realigns hydrogen atoms in your body. Radio waves cause these aligned atoms to produce very faint signals, which are used to create cross-sectional MRI images. Although there are no x-ray, gamma or beta radiation concerns associated with MRI procedures, the powerful magnetic field that exists within and surrounding the MRI machine requires specific safety precautions.
The presence of metal in your body may be a safety risk or can affect a portion of the image. Before receiving an MRI, tell the technologist if you have any metal or electronic devices in your body, such as a pacemaker, artificial heart valves, implantable heart defibrillator, heart defibrillator, metal clips, metallic joint prostheses, cochlear implants, piercings, bullets, shrapnel or any other type of metal fragment.