NEW YORK (Reuters Health) – Magnetic resonance imaging (MRI) machines may displace the magnets of cochlear implants or cause extreme discomfort for some wearers, according to a new study.
More than 300,000 people worldwide now have a cochlear implant, a small electronic device with an external transmitter held in place behind the ear with a magnet and an internal electrode array. The devices can help restore a sense of hearing to the profoundly deaf, according to the National Institute on Deafness and Other Communication Disorders.
“There have been several reports of adverse events, such as magnet displacement and polarity changes, following MRI in patients with cochlear implants,” said senior author Dr. Jae Young Choi of the Department of Otorhinolaryngology at Yonsei University College of Medicine in Seoul, South Korea. “The exposure of the internal magnet to a strong electromagnetic field can induce significant magnetic forces and cause displacement of the implant.”