Thread: CT scans can cause medical device malfunction

The United States Food and Drug Administration (FDA) has alerted health professionals in U.S. to the possibility that x-rays used during CT examinations may cause implanted and external electronic medical devices to malfunction.

FDA assured that most patients with electronic medical devices undergo CT scans without any adverse consequences. However, it has received a few reports of adverse events in which CT scans may have interfered with electronic devices such as pacemakers, defibrillators, neurostimulators and implanted or externally worn drug infusion pumps.FDA is continuing to investigate this issue with the cooperation of manufacturers.

Till now, FDA has not received any reports of deaths from CT scanning of medical devices. In one study, researchers found transient malfunctioning of pacemakers due to CT examinations in six out of 11 patients as indicated by their ECGs during the CT examinations. They examined the effect of CT on a pacemaker in a human body model with and without shielding by rubber or lead. X-rays from CT equipment caused the malfunctioning as they could show that lead shielding prevented it . In another study, researchers exposed 21 devices to X rays from CT scanners.

They found malfunctioning in 20 out of 21 devices at maximum dose levels and in 17 out of 21 at typical dose levels. Two devices inhibited for more than 4 seconds in spiral mode at clinical dose levels. Effects occurred only if the x-ray beam passed directly over the device.

In another investigation, an implanted neurostimulator unit give the patient a shock when he was scanned (CT) in that area.

Source : FDA Journals

Parts taken from DOTmed.com - CT Scans May Cause Electronic Medical Devices to Malfunction: FDA