MRI scans may damage cochlear implants

Patients with cochlear implants may want to steer clear of certain magnetic imaging devices, such as 3T MRI machines, because the machines can demagnetize the patient’s implant, according to new research published in the December 2008 issue of Otolaryngology – Head and Neck Surgery.

The study, conducted by a team of German reasearchers from the International Neuroscience Institute, Hannover, and the Medical University of Hannover, and American researchers from Vanderbilt University, Nashville, Tenn,tested several cochlear device magnets on a 3T MRI scanner with active shielding at a variety of angles (0º, 80º, 90º, 100º, 110º, and 180º). The researchers discovered that during routine use of 3T MRI machines at angles above 80º, an unacceptable level of demagnetization was reached, causing permanent damage to devices with non-removable magnets, and creating the potential of exposing patients to undesirable magnetic forces.

3T MRI scanners are the next generation of MRI scanners and are significantly more powerful than 1.5T MRI scanners.

As a result of their findings, the study authors recommend that MRI scans on patients with cochlear implants should be performed using a 3T MRI machine only if a 1.5T machine is not available, and if the benefits of the scan far outweigh the risk of cochlear implant demagnetization.

Source: American Academy of Otolaryngology — Head and Neck Surgery