MRI machines may damage cochlear implants
Patients with cochlear implants may want to steer clear of certain magnetic imaging devices, such as 3T MRIs, because the machines can demagnetize the patient's implant, according to a study published in the December issue of Otolaryngology – Head and Neck Surgery.
A cochlear implant, a surgically implanted in the inner ear and activated by a device worn outside the ear, restores partial hearing to the deaf. It is estimated that more than 100,000 people have cochlear implants.
Omid Majdani, MD, PhD, from the Medical University of Hannover, Clinic for Otolaryngology in Hannover, Germany, and colleagues tested several cochlear device magnets on a 3T MRI scanner with active shielding at a variety of angles (0 degrees, 80 degrees, 90 degrees, 100 degrees, 110 degrees and 180 degrees).
The researchers discovered that during routine use of 3T MRI machines at angles above 80 degrees, 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.
As a result of their findings, the 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.
A cochlear implant, a surgically implanted in the inner ear and activated by a device worn outside the ear, restores partial hearing to the deaf. It is estimated that more than 100,000 people have cochlear implants.
Omid Majdani, MD, PhD, from the Medical University of Hannover, Clinic for Otolaryngology in Hannover, Germany, and colleagues tested several cochlear device magnets on a 3T MRI scanner with active shielding at a variety of angles (0 degrees, 80 degrees, 90 degrees, 100 degrees, 110 degrees and 180 degrees).
The researchers discovered that during routine use of 3T MRI machines at angles above 80 degrees, 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.
As a result of their findings, the 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.