Because the strong magnetic field used for MRI will pull on any iron-containing object in the body, MRI staff will ask whether you have a heart pacemaker or implanted defibrillator, implanted port, infusion catheter (often referred to by brand names such as Port-o-cath, Infusaport or Lifeport), intrauterine device (IUD), or any metal plates, pins, screws or surgical staples in your body. In most cases, surgical staples, plates, pins and screws pose no risk during MRI. Red dyes used in tattoos and permanent eyeliner may contain metallic iron oxide and could heat up during MRI; however, this is rare. You will be asked if you have ever had a bullet or shrapnel in your body, or ever worked with metal. If there is any question of metal fragments, you may be asked to have an x-ray that will detect any metal objects.
The radiologist or technologist may ask about drug allergies and whether you have undergone any surgery in the past. If you are or might be pregnant, mention it to the MRI staff. Some patients who undergo MRI in an enclosed unit may feel confined or claustrophobic. If you are not easily reassured, a sedative may be administered. Less than one in 20 patients will require medication.