In a recent article, the Institute for Safe Medication Practices (USA) talks about a hazard that many people may not know about. Transdermal medication patches, like those that deliver nicotine, testosterone and nitroglycerin, can cause burns if a patient wears one during an MRI procedure. That's because some transdermal patches have an aluminized backing. The backing isn't ferromagnetic and so it's not attracted to the magnetic field of an MRI system. However, this metallic component conducts heat, and so it can cause burns.

We've recently received reports of patients wearing nicotine transdermal patches who were burned during an MRI exam. In one case, a patient entered an MRI scanner wearing a Habitrol 21 mg patch. He started thrashing when the third scanning cycle started, and the test was stopped immediately. The patient reported that his arm was burning and there was a small, denuded blister where the patch had been. In another report, a patient had a short MRI of the lumbar spine while wearing a nicotine transdermal patch. Later, the patient complained of burn lines on his upper arms.

Here's ISMP's recommendation. Before MRI exams, ask all patients whether they use any medication patch. Unless you're sure the patch doesn't contain metal, tell the patient to remove it temporarily, in order to avoid possible burns.

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