Cochlear implants (CIs) and magnetic resonance imaging (MRI)


© Adam Ciesielski - Sxc

A new study carried out at the Department of Otorhinolaryngology at Yonsei University College of Medicine in Seoul, South Korea, has examined adverse events in CI patients during MRI. According to the authors of the study, the results of which were recently published in the Journal JAMA Otolaryngology -- head & neck surgery, CI recipients need to fully understand both the potential complications related to MRI and the possible discomfort that they may feel during the procedure.

The clinicians carried out a retrospective review of the medical records of 18 patients with CIs who underwent MRI, and interviewed the patients. They found that five patients with head bandages were unable to complete their MRI scans due to pain, one of these patients experienced magnet displacement, and another patient underwent surgery for magnet removal and reinsertion. However, subsequent auditory performance in the CI recipients who had a major adverse event was not affected.

“There have been several reports of adverse events, such as magnet displacement and polarity changes, following MRI in patients with cochlear implants,” explains senior author on the paper Dr. Jae Young Choi. “The exposure of the internal magnet to a strong electromagnetic field can induce significant magnetic forces and cause displacement of the implant.” Another problem is that interactions between the MRI magnetic fields and the magnet in the CI may distort scan results.

“Appropriate sedation and head positioning can alleviate patient discomfort or pain during MRI scans,” Choi added. “Therefore, patients with cochlear implants who undergo MRI scans should be carefully monitored and measures should be taken to minimize the likelihood of adverse events.”

Source: Reuters; Kim BG, et al. Adverse Events and Discomfort During Magnetic Resonance Imaging in Cochlear Implant Recipients. JAMA Otolaryngology -- head & neck surgery. 2014 Nov 20.