Effect of Implant Position on Magnetic Resonance Image Distortion

Patients with Neurofibromatosis type 2 (NF2) almost always develop acoustic neuromas in both ears. As a result of the tumours themselves or the treatment of the tumours, many patients become profoundly deaf in both ears. It is possible to restore a degree of hearing by placing a hearing implant in the brainstem adjacent to the hearing pathways within the brain. This is termed an auditory brainstem implant (ABI). The aim of this study is to find the optimum head position in relation to the MRI magnet field, which would produce least area of image distortion in patients with ABIs. This will be of benefit in optimising the MR imaging in future patients with implants.