Comparison Between Transimpedance Matrix (TIM) Measurement and X-ray Fluoroscopy for Intraoperative Electrode Array...

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Medical Imaging

Background:

• Intraoperative detection of electrode array tip fold-over is critical for successful cochlear implantation.
• X-ray fluoroscopy is a conventional method, but its accuracy and inter-rater reliability can be variable.

Purpose of the Study:

• To compare the efficacy of Transimpedance Matrix (TIM) measurement against X-ray fluoroscopy for detecting electrode array tip fold-over during cochlear implant surgery.
• To assess the agreement between raters and between the two imaging modalities.

Main Methods:

• A retrospective agreement study was conducted involving 42 patients (47 ears) who received the Slim Modiolar Electrode.
• Five raters evaluated TIM heatmaps and X-ray fluoroscopy images for electrode array tip fold-over.
• Agreement was assessed between individual evaluations and intraoperative diagnoses, as well as inter-method and inter-rater agreement.

Main Results:

• A tip fold-over occurred in 6.4% of cases.
• TIM-measurement demonstrated 99% agreement with intraoperative evaluation (Cohens κ = 0.915) and near-perfect inter-rater agreement (Fleiss’ κ = 0.850).
• X-ray fluoroscopy showed 88% agreement (Cohens κ = 0.378) and only fair inter-rater agreement (Fleiss’ κ = 0.286), with some raters misdiagnosing tip fold-overs.

Conclusions:

• TIM-measurement is a highly accurate and reliable method for intraoperative detection of electrode array tip fold-over in cochlear implantation.
• TIM-measurement shows significant potential to replace X-ray fluoroscopy, particularly with flexible, precurved electrode arrays.