Abstract:
Objective: To further enrich quantitative imaging reference data for the fine inner ear anatomy of the Chinese population, this study aimed to establish the 95% normal reference values of 16 core quantitative anatomical parameters of key inner ear structures (cochlea, vestibule, semicircular canals, and common crus), based on ultra-high resolution computed tomography (U-HRCT), using manual labeling and quantitative measurement. Methods: U-HRCT images of the temporal bone were collected from 113 adults free of middle ear, inner ear, and temporal bone lesions. Two radiologists performed slice-by-slice delineation of six key inner ear structures using professional software, followed by three-dimensional reconstruction. Sixteen core structural parameters were then measured. The intraclass correlation coefficient (ICC) was used to assess inter-observer reliability. Multiple linear regression analysis was used to explore the independent effects of age, sex, and laterality on these parameters. The percentile method was used to establish 95% reference intervals. Results: All interobserver ICC values were >0.85, reflecting excellent measurement consistency and high reliability of the data. The 95% reference values of the 16 U-HRCT-derived inner ear quantitative parameters were established for the first time. Multiple linear regression analysis showed that sex was the main independent influencing factor for inner ear parameters, and most cochlear, vestibular, and semicircular canal parameters had significant sex-associated discrepancies. Age and laterality did not have a significant effect on the morphological structure of the inner ear. Conclusion: The constructed database of quantitative reference values for pivotal inner ear structures is robust and reproducible. It can serve as a standardized ground truth to validate automated inner ear segmentation algorithms, to obtain quantitative evidence for precision otosurgical planning, for inner ear pathological studies and anatomical mechanistic investigations, and to facilitate the systematization and quantitative transformation of inner ear imaging assessment in the Chinese population.