Automatic electrode scalar location assessment after cochlear implantation using a novel imaging software.

Area of Science:

• Oto-neurology
• Medical Imaging
• Biomedical Engineering

Background:

• Current clinical imaging methods like computed tomography (CT) have limitations in visualizing intracochlear structures due to low resolution and artifacts, hindering accurate cochlear implant electrode array location assessment.
• Standardized image-based trauma scaling is needed for clinical-CT images to reliably assess electrode position.

Purpose of the Study:

• To evaluate the accuracy of novel imaging software in detecting the scalar location of cochlear implant electrode arrays.
• To introduce and validate a standardized grading scale for electrode scalar location.

Main Methods:

• Six human cadaveric temporal bones were implanted with cochlear electrode arrays (Advanced Bionics SlimJ and Mid-Scala).
• Pre- and postoperative clinical-CT scans were acquired, alongside postoperative micro-CT scans for validation.
• A novel software's assessment of electrode scalar location was compared against evaluations by two experienced otosurgeons and micro-CT findings, using a 3-step grading scale (scala tympani, interaction with basilar membrane/osseous spiral lamina, scala vestibuli).

Main Results:

• The software demonstrated high sensitivity (100%) and specificity (98.7%) in rating electrode location.
• A strong correlation (kappa > 0.890) was observed between the software's ratings, surgeon evaluations, and micro-CT data.
• The introduced 3-step grading scale proved effective for assessing clinical CT images.

Conclusions:

• The novel software provides a fast, reliable method for evaluating cochlear implant electrode scalar location using cone beam CT scans.
• The developed grading scale is suitable for clinical CT image assessment, potentially improving routine clinical practice.