Because MRI uses powerful magnets, the presence of metal in your body may be a safety hazard or affect a portion of the MRI image. Before having an MRI, tell the technologist if you have any metal or electronic devices in your body, such as:
- Metallic joint prostheses
- Artificial heart valves
- An implantable heart defibrillator
- A pacemaker
- Metal clips
- Cochlear implants
- A bullet, shrapnel or any other type of metal fragment
If you have tattoos, ask your doctor whether they might affect your MRI. Some of the darker inks may contain metal.
Before you schedule an MRI, tell your doctor if you think you're pregnant. The effects of magnetic fields on fetuses aren't well-understood. Your doctor may recommend choosing an alternative exam or postponing the MRI.
It's also important to discuss any kidney or liver problems with your doctor and the technologist, because problems with these organs may limit the use of injected contrast agents during your scan.