High-resolution Flat-panel Computed Tomography Analysis of Intrascalar Position and Electrode Contact Orientation: A...

Area of Science:

• Otolaryngology
• Medical Imaging
• Biomedical Engineering

Background:

• Accurate cochlear implant (CI) electrode placement is crucial for hearing outcomes.
• Current methods for assessing intrascalar location and orientation are limited.

Purpose of the Study:

• To present a novel method using in-vivo high-definition flat-panel computed tomographic imaging (FPCT) to determine CI electrode intrascalar location and orientation.
• To establish a model for describing electrode contact directionality.

Main Methods:

• Retrospective analysis of postoperative FPCT scans in adult patients with CIs.
• Utilized mid-modiolar image slices and 3D renderings to measure insertion angle, intrascalar location, and electrode contact orientation.
• Defined electrode contact orientation relative to the modiolus and cochlear partition.

Main Results:

• Average angular insertion depth was 494°.
• Radial distance from the lateral wall to the electrode decreased with depth.
• Basal contacts averaged 59° towards the cochlear partition, while apical contacts averaged 28° towards the modiolus.

Conclusions:

• FPCT enables in-vivo mapping of CI electrode positioning and orientation.
• Measurements align with anatomical expectations and provide a basis for describing electrode directionality.
• Future research will correlate these imaging findings with electrophysiologic and psychophysical outcomes.