CT Scans Interfering with Some Medical DevicesJul 15, 2008 | Parker Waichman LLP CT (Computer Tomography) scans can cause some electronic medical devices, such as pacemakers, cardiac defibrillators and insulin pumps to malfunction. According to a Food & Drug Administration (FDA) alert issued yesterday, CT scans have caused such medical devices to shock patients, or to emit inaccurate signals.
According to the alert, the FDA has confirmed six reports of devices that malfunctioned after a CT scan and another nine reports of suspected problems. No deaths have been reported as a result of the malfunctions. Devices that could be affected by CT scans include cardiac pacemakers, implantable cardiac defibrillators, neurostimulators, drug infusion and insulin pumps, cochlear implants and retinal implants, the FDA said. People with these devices are already prohibited from undergoing MRI procedures because of similar risks.
In the reports received by the FDA, the following adverse events were likely to have been caused by x-rays from CT scans:
- Unintended “shocks” (i.e., stimuli) from neurostimulators
- Malfunctions of insulin infusion pumps
- Transient changes in pacemaker output pulse rate
Problems with electronic medical devices that might be caused by CT scanner interference include:
- generation of spurious signals, including cardiac defibrillation pulses
- misinterpretation of signals produced by the x-rays as actual biological signals
- missed detection of actual biological signals
- resetting or reprogramming of device settings
The agency recommends that CT operators use the least amount of X-ray exposure possible and stand prepared to treat adverse reactions, among other measures. Patients with affected devices should:
- Discuss the risks and benefits of CT scans versus other types of medical imaging with your doctor.
- If device has external parts, ask your doctor whether the device can safely be turned off or temporarily moved if the area of your body where it is located needs to be scanned. Remember to turn on and reposition the device once the CT scan is complete.
- Remind the technologist or physician performing the CT scan that you have an electronic medical device.
- Report any pain, such as sudden shocks, that occur during a CT scan. CT scans should be painless. A sudden shock could mean there is a problem with your electronic medical device.