By guest blogger Michael Cohen:
Each year millions of Americans under go magnetic resonance imaging scans to diagnose problems ranging from cancer to sports injuries. MRIs use a high powered magnet and pulses of radio-wave energy to enable doctors to view organs and other internal body parts, often revealing problems that may not be visualized with other imaging methods.
And we have all heard about scary incidents involving MRI machines and metal objects. For example, not too long ago, a 6-year-old child suffered a skull fracture and bleeding in the brain after a metal oxygen tank flew across the room and hit him in the head during an MRI.
The strong magnetic field created by the scanning machine can suddenly attract metal objects. That's why before an MRI scan, patients are told to remove all metal objects they may be wearing. They are also asked whether they have any metal inside them. Things like pacemakers, prosthetic hips, or retained bullets and shrapnel may cause problems during the test.
A less well-known problem involves medication patches and patients should remove them before an MRI test - not because the machine would pull off the patch but to prevent burns. Many patches have an aluminum backing, which can become very hot during an MRI. For example, several patients who were wearing a nicotine patch during an MRI developed redness and blistering (second degree burns) on the skin underneath the patch. Patches in this category include nicotine patches, testosterone patches, birth control patches, nitroglycerine patches, motion sickness patches, and many others.
Many MRI facilities use a check list. They'll question you about metal objects and also ask if you wear a medicine patch. However, not all will do this, so if you need to get an MRI scan and you use a patch (including a nicotine skin patch), let the MRI center staff know about it when you call to make an appointment for a scan. They'll tell you whether it should be removed before the test and when to put it back on.
The labeling for most of the medicated patches that contain metal in the backing provides a warning to patients about the risk of burns if the patch is not removed before an MRI scan. However, not all patches that contain metal have this warning. FDA says they are working with manufacturers of these patches to assure that product labeling warns about the potential for burns in patients undergoing an MRI. A list of these drugs and additional information is available from the FDA.
For information on the Institute for Safe Medication Practices' consumer website go www.consumermedsafety.org
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