Magnetic Resonance Imaging of Advanced Bionics HiRes Ultra 3D Cochlear Implants

Motivation: A cochlear implant (CI) contains an implanted magnet placed under the scalp. Newer rotating magnet designs facilitate safe and comfortable scanning up to and including 3 T. However, MRI of the head is still confounded by image distortion. Goal(s): To characterise CI artefacts at 3 T. Approach: T2DRIVE and T1-weighted mDIXON images were acquired in CI users, normally-hearing participants, and a phantom. Results: Visibility of bilateral internal auditory canals and cochleae varied across three CI users. Pre-surgical assessment will be beneficial on an individual basis to maximise the chances of successful post-operative MR acquisition. Impact: Bilateral internal auditory canals can be visualised despite the presence of a cochlear implant (CI): an assessment of the effect of a CI on the usability of clinical MR images in CI users, normally-hearing individuals, and a phantom.