(806) Analysis of Cochlear Duct Length Based on Computer Tomography Images of Temporal Bones

Introduction: The purpose of the research was to analyze cochlear length in the Polish population and establish normative reference values, including sex-specific differences, USING computed tomography (CT) imaging of the temporal bone.

Methods: The study design: Retrospective cohort study,
Year(s)/Month(s) Study Conducted: 2024-2025
Disease/Condition Studied: Cochlear Duct Length
Subjects Studied: 1056 cochleae, 528 patients
Setting in Which Subjects Studied: Tertiary referral center
A total of 1056 cochleae were examined, derived from 528 individuals. Of these, 517 (49%) belonged to females and 539 (51%) to males. Inclusion criteria were normal cochlear morphology and high-quality imaging data.
High-resolution temporal bone CT images were analysed using OTOPLAN software. All cochlear duct measurements were performed by an experienced radiologist.
Mean cochlear duct length and its distribution within the Polish population, with analysis of sex-related differences and categorisation into terciles for both sexes.

Results: The mean cochlear length in the total population was 35.51 mm (SD = 1.75; range 27.1–41.2 mm). Although the distribution was approximately normal, statistical testing revealed significant deviations (p < 0.001). Female cochleae were significantly shorter than male cochleae (M = 34.96 mm; SD = 1.61 vs. M = 36.00 mm; SD = 1.73; p < 0.001). The sex-specific tercile boundaries were as follows: for females, ≤34.4 mm (short), 34.5–35.4 mm (average) and ≥35.5 mm (long); and for males, ≤35.4 mm, 35.5–36.7 mm and ≥36.8 mm.

Conclusions: This study provides the first normative data on cochlear length in the Polish population. These results can serve as a reference for comparative international comparisons and support clinical decision-making in cochlear implant electrode selection and surgical planning.