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The radiation used during computed tomography (CT) scans could cause some implanted and external medical devices to malfunction, according to a public health alert from the FDA's Center for Devices and Radiological Health. These devices include pacemakers, defibrillators, neurostimulators, and implanted or externally worn drug-infusion pumps. Potential malfunctions include false signals (such as cardiac defibrillation pulses), misinterpretation of signals produced by the X-rays as actual biological signals, missed detection of actual biological signals, and resetting or reprogramming of device settings.


Most patients with electronic medical devices undergo CT scanning without incident, according to the FDA. When malfunctions do occur, they often result from direct exposure of the medical device to high radiation doses.

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The alert recommends steps to limit the exposure of medical devices to radiation. Some strategies involve moving external devices out of scan range and using the lowest possible radiation dose. For more information, visit the FDA's Web site at