Ferromagnetic foreign bodies such as shell fragments, or metallic implants such as surgical prostheses and ferromagnetic aneurysm clips are also potential risks.

However MRI is usually contraindicated if the patient has any type of medical implant, such as vagus nerve stimulators, implantable cardioverter-defibrillators, loop recorders, insulin pumps, cochlear implants, deep brain stimulators, metallic foreign bodies (e.g. shrapnel or shell fragments), or metallic implants such as surgical prostheses.