Radiation-free cochlear implant position estimation in pediatric patients using impedance telemetry.

Background: Cochlear implants (CIs) play a crucial role in providing children with profound hearing loss the ability for auditory perception and spoken language development. Following implantation, patients typically undergo a computed tomography (CT) or X-ray examination to assess electrode positions in the cochlea. Besides economic factors, this imposes radiation risks on patients, particularly for younger patients who are more sensitive to its harmful effects.

Objective: This study aims to evaluate the performance of an impedance telemetry-based estimation algorithm for assessing postoperative CI placement. While the algorithm has been validated in an adult cohort, this research explores its applicability in pediatric patients.

Materials and methods: The insertion depth estimation algorithm was validated on a dataset of 59 pediatric cases and evaluated using different classification metrics. Impedance telemetry data was combined with demographic data and morphological parameters of the cochlea and used as input data for the algorithm. The algorithm predictions were compared with ground truth labels derived from X-ray and CT scans.

Results: The algorithm demonstrated a root mean squared error (RMSE) of 1.53mm for insertion depth prediction, compared to 1.01mm in the original report. In terms of classification, the algorithm successfully detected all cases with partially inserted electrodes, although three cases were detected as false positives.

Conclusion: The results highlight the algorithm's potential for clinical decision support in assessing post-implantation outcomes, monitoring electrode migration, and detecting extracochlear electrodes. A larger dataset with more partial insertion cases would be required for additional training and validation of the algorithm. Assessing electrode placement through impedance measurements would eliminate the need for additional radiography, reducing radiation exposure for future patients while also saving the clinic significant cost and time.