Watchdog warns over MRI injuries in people with implanted stimulators

19 May 2005

The US Food and Drug Administration
(FDA) has issued a reminder to radiology personnel and doctors about
the risk of injury to people with implanted neurological stimulator
(such as the vagus nerve stimulator) when they undergo MRI scans.

reports of serious injury have been received by the FDA, including
cases where the electrodes at the end of the wires have heated,
resulting in injury to the surrounding tissue. They warn that although
the reports involved deep brain stimulators and vagus nerve
stimulators, similar injuries could be caused by any type of implanted
neurological stimulator, such as spinal cord stimulators, peripheral
nerve stimulators, and neuromuscular stimulators.

FDA recommend that any doctor who implants or monitors patients with
implanted neurological stimulators should explain to the patient what
MRI procedures are and stress that they must consult with their doctor
before having any MRI scan to find out whether it can be performed

or health care professionals who use MRI equipment are advised to
carefully screen for any implanted devices prior to performing an MRI
procedure, even if the implanted device has been turned off. The FDA
also advises questioning patients about previously implanted devices
that have been removed. Leads, or portions of leads, are often left in
the body after the stimulator is removed, and these may act as an
antenna and become heated.

the patient does have an implanted neurological stimulator,
radiologists should consider consulting with the referring doctor to
discuss other imaging options. For some implanted neurological
stimulators, certain MRI procedures should not be performed.