Is MRI safe?
MRI acquires images by using strong magnetic fields rather than the ionizing x-rays commonly used in Radiology. Therefore, you will not be exposed to any radiation during the exam. The magnetic fields are not known to be harmful in any way.
Yet because the exam does rely on powerful magnetic fields, certain precautions must be taken concerning metal objects which may be influenced by exposure to the magnetic fields.
For example, certain metal objects cannot be placed within the magnetic field because they would malfunction, resulting in injury or even death. These include:
- Cardiac pacemakers
- AICD (defibrillators)
- Neurostimulators
If you have a pacemaker or any of the above, you cannot have an MRI scan.
There are other metal objects placed within the body that may cause injury to the patient. These would include artificial heart valves, particularly old St. Jude prosthetic valves. Other metal objects that are of concern include the following:
- Aneurysm clips, plates, screws, or shunts
- Possible exposure to metal in your eyes (welding or machining)
- Ear implants, particularly cochlear implants
- Prior cardiac or vascular surgery involving metal stents
- Devices for pain control (tens unit) or nerve stimulator
- Artificial joints, pins or rods within bone
- Bullets or shrapnel
- Intra-uterine devices (IUD)
You must make us aware if you have any of these metal exposures prior to undergoing your MRI. Certain precautions can be taken to prevent any injury which may occur as a result of exposure to the MRI’s magnetic field.
Two other areas of concern need to be mentioned. If you are pregnant or think you may be pregnant, undergoing an MRI exam would require you to sign a consent, because the effects of MRI on pregnancy are not known.
If you are claustrophobic, you may have difficulty tolerating being in the magnet while the images are acquired. We can give you medicine for sedation, but order must be on your chart so that it may be given. Please notify us ahead of time if either of these conditions apply to you so that appropriate measures may be taken before you arrive. You will need to arrange for someone to drive you home if you receive sedation.