Comparison of Cochlear Implant Magnets and Their MRI Artifact Size

Area of Science:

• Medical Imaging
• Otolaryngology
• Biomedical Engineering

Background:

• Cochlear implant (CI) magnet and surgical advancements enable MRI use.
• MRI is now a diagnostic tool, not a contraindication for CIs.
• Magnet artifact size is crucial for assessing cochlea and internal auditory canal (IAC) visibility.

Purpose of the Study:

• To compare maximum MRI artifact sizes related to different cochlear implant magnet systems.
• Evaluate artifact variations across various CI brands under different MRI strengths.

Main Methods:

• In vivo measurement of MRI artifacts at 1.5 and 3 Tesla.
• Tested three CI magnet systems: AB 3D, Medel Synchrony, and Oticon ZTI.
• Used TSE T2w MRI sequences on axial and coronal planes in volunteers.

Main Results:

• Intraindividual artifact size differences were smaller than interindividual differences.
• 3 Tesla MRI scans showed differences in soft artifact areas compared to 1.5 Tesla.
• No major differences in maximum implant magnet artifact sizes were observed among the three systems.

Conclusions:

• Maximum artifact sizes from the three tested cochlear implant magnet types showed no significant variations.
• This suggests comparable MRI compatibility across these CI systems regarding magnet artifacts.