The implants that are most prone to causing problems for patients with MRIs are the following:
- Pacemakers or heart valves
- Metal implants in a patient's brain
- Metal implants in a patient's eye or ears
- Infusion catheters
In addition, patients who have been injured by bullets or shrapnel, or patients who work with metals, should be specifically questioned to determine if a MRI is possible.
Some metal implants typically do not cause problems. Most orthopedic and dental implants are not magnetic. These include hip and knee replacements; plates, screws, and rods used to treat fractures; and cavity fillings. All of these metal implants can distort the MRI image if near the part of the body being scanned, but they will usually not cause problems. Even if you think the metal implant is compatible with the MRI machine, you must let the MRI personnel know in order to ensure this metal is compatible.