Assessing bone radiodensity and thickness in cochlear implant patients through manual photon-counting CT image...

Area of Science:

• Otolaryngology
• Neurosurgery
• Medical Imaging

Background:

• Facial nerve stimulation (FNS) is a potential complication during cochlear implant surgery.
• Far advanced otosclerosis (FAO) may affect the anatomical relationship between cochlear implant electrodes and the facial nerve.
• Understanding bone characteristics is crucial for assessing FNS risk.

Purpose of the Study:

• To compare bone radiodensity and thickness between cochlear implant electrodes and the facial nerve in patients with and without FNS, considering the presence of FAO.
• To assess the role of bone characteristics in FNS risk using photon counting-computed tomography (PC-CT).

Main Methods:

• A case-control study involving four groups: FNS patients with/without FAO and control patients with/without FAO.
• Manual segmentation of PC-CT scans using ITK-SNAP software to measure bone radiodensity and thickness.
• Analysis of clinical data including surgical details, complications, and hearing outcomes.

Main Results:

• No significant differences in demographics, surgical outcomes, complications, or hearing outcomes were found between FNS and non-FNS groups.
• Patients with FAO exhibited significantly lower bone radiodensity (1483.57 HU) compared to those without FAO (2403.51 HU).
• No significant differences in bone radiodensity or thickness were observed between FNS and non-FNS patients, although one non-FAO FNS patient had a very short electrode-facial nerve distance.

Conclusions:

• Bone radiodensity and thickness alone do not fully explain FNS in cochlear implant patients, even in the context of FAO.
• While lower bone radiodensity in FAO doesn't directly correlate with FNS, reduced bone thickness in specific instances might contribute to FNS risk.