Magnetic Resonance Imaging (MRI) of the Head
There are no known harmful effects from the strong magnetic field used for MRI. But the magnet is very powerful. The magnet may affect pacemakers, implantable cardioverter-defibrillators (ICDs), artificial limbs, and other medical devices that contain iron. The magnet will stop a watch that is close to the magnet.
Metal pieces in the eyes can damage the Reference retina Opens New Window. If you might have metal pieces in your eye, an X-ray of the eyes may be done before the MRI. If metal is found, the MRI will not be done.
Iron pigments in tattoos or tattooed eyeliner can cause skin or eye irritation.
An MRI can cause a burn with some medicine patches. Be sure to tell your doctor if you are wearing a patch.
There is a small chance of an allergic reaction if contrast material is used during the MRI. But most reactions are mild and can be treated with medicine. Contrast material that contains gadolinium may cause a serious problem (called nephrogenic systemic fibrosis) in people with Reference kidney failure Opens New Window. If you have decreased kidney function or serious kidney disease, tell your doctor before having an MRI scan.
There also is a slight risk of an infection at the IV site if contrast material was used.
|By:||Reference Healthwise Staff||Last Revised: Reference December 9, 2010|
|Medical Review:||Reference Kathleen Romito, MD - Family Medicine
Reference Paul D. Traughber, MD - Diagnostic Radiology