X-ray guided anatomy-based fitting: The validity of OTOPLAN

Area of Science:

• Otolaryngology
• Medical Imaging
• Biomedical Engineering

Background:

• Anatomy-based fitting (ABF) represents an advancement in cochlear implant outcomes.
• Plain X-rays are emerging as a viable alternative to computed tomography (CT) for ABF construction.
• This study evaluates OTOPLAN® software's capability in generating ABF using plain X-ray imaging.

Purpose of the Study:

• To assess the feasibility and validity of OTOPLAN® software for creating ABF maps.
• To compare measurements derived from plain X-ray images versus CT scans for ABF analysis.
• To evaluate the inter-rater reliability of measurements obtained from both imaging modalities.

Main Methods:

• Retrospective analysis of postoperative CT scans and plain X-ray images from 54 cochlear implant patients.
• Utilized OTOPLAN® software to measure angular insertion depth (AID) and center frequency of electrode contacts.
• Assessed inter-rater reliability for measurements derived from both CT and X-ray data.

Main Results:

• No significant statistical or clinical differences were found between CT and X-ray measurements for AID and center frequency.
• Absolute differences between CT and X-ray were minimal (0.0-4.6 degrees for AID, 0.2-0.5 semitone for frequency).
• High inter-rater reliability (intraclass correlation coefficient > 0.95) was observed for both imaging modalities.

Conclusions:

• Postoperative X-ray images processed by OTOPLAN® software are valid for creating ABF maps.
• Plain X-rays offer a reliable method for anatomy-based fitting in cochlear implant surgery.
• This validates X-ray imaging as a practical alternative to CT for ABF planning and analysis.