MRI (or Magnetic Resonance Imaging) is a way for radiologists to view the body using a combination of magnets and radiofrequency waves. MRI is a particularly great technology for showing anatomy and for studying the brain, joints, abdomen, back, spine and heart, among other organs. While an MRI requires no exposure to radiation, the strong magnetic force creates special considerations. Individuals with most pacemakers and some other implanted electronic devices cannot enter the MRI room. Likewise, metal of any kind cannot be brought into the MRI suite as metal objects can become missiles!
When getting an MRI, patients can expect to experience a few unique sights, sounds and sensations. Most MRI studies can be completed in about 20-40 minutes.
Sights and Sounds
What patients will see: a large machine (that’s the magnet!) with round hole and a table going through it. The table will be moved into the MRI machine. For the few who find smaller spaces uncomfortable, closing their eyes and visualizing open spaces usually solves the issue. Patients must remain still as image sequences last from a few to several minutes, and motion can lead to blurred images.
The images are made with radiofrequency pulses which create a loud series of noises, often like a loud knocking, for which ear protection is needed and provided.
There are a few mild or passing physical sensations that may be experienced in the magnet.
Metal on or in the body may create sensations when in the magnet. Even small amounts of metal, as for instance in certain tattoo inks, may lead to local warming. Metal fragments in the body from an old injury may also cause local heating. While most of the time these effects are minimal, communication before you have your study and during is most important! If it feels wrong, let the technologist know immediately! Many surgically placed metal objects are fine, but fully discuss these with the technologist for safety.
If your exam requires the injection of contrast - a clear IV medication that allows better definition of the inner organs - patients can feel a cool sensation in the arm during the injection. As with any medication, side effects and rarely reactions can occur. Your technologist will help explain these.
Because the magnet of an MRI is always on, it is important to remember that all things magnetic can be drawn to it. What does this mean to the average person? Don't have your credit cards or other metal objects in your pocket when you walk in the room! All patients are thoroughly screened for safety but you can help by knowing these basics of the MRI.
Originally published 5/31/13 on diagnosticimagingcenterskc.com.