Comparison of bandaging techniques to prevent cochlear implant magnet displacement following MRI

Introduction For cochlear implants (CI) with removable magnets, a pressure bandage usually is recommended during MR imaging to avoid magnet dislocation. Nevertheless, this complication is regularly observed despite applying a pressure bandage. The aim of this study was to compare various bandaging techniques to avoid magnet displacement. Materials and methods As an experimental model a force measuring stand was developed and validated, on which the process of magnet dislocation could be simulated on a cochlear implant. In a test series with six combinations of cohesive and elastic bandages with different counter pressure elements (CPE), the forces required to induce magnet dislocation against the resistance of a compression bandage was determined. In addition, the inter- and intraindividual variability of the compression bandages was measured for ten different users. Results The cohesive bandage had the lowest average holding force of 10.70 N. The elastic bandage developed more than four times the retention force of the cohesive bandage (44.88 N, p