Cochlear view: postoperative radiography for cochlear implantation

Abstract

Objective: This study aimed to define a spatial position of the cochlea in the skull based on anatomical studies and to design an appropriate method of skull radiography for demonstration of the multichannel intracochlear electrode array and the structures of the inner ear, for use in evaluating the electrode position and its related pitch perception.

Background: The conventional skull radiograph (plain radiograph) can offer a complete and direct image of an intracochlear electrode array, if the x-ray is directed to the cochlea and parallel to the axis of the cochlea.

Methods: Measurement from computed tomography imaging and three-dimensional reconstruction were performed to define the spatial position of the cochlea in the skull.

Results: A radiographic projection, the cochlear view, was designed. A detailed radiographic method and radiologic interpretation of the cochlear view is described. An improved clinical method for measuring the longitudinal and angular position of the electrodes from the cochlear view is recommended.

Conclusions: The application of the cochlear view has proved that it is beneficial postoperatively in documenting the results of cochlear implantation, and in evaluating the depth of insertion and position of individual electrodes. It serves as a valuable reference for managing frequency mapping, optimizing speech processing strategies, and further research purposes. The method can be widely used in cochlear implant clinics because of its simplicity, low radiation, speed, and minimal cost.