Practicable Assessment of Cochlear Size and Shape from Clinical CT Images
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Gee, A., Zhao, Y., Treece, G., & Bance, M. (2020). Practicable Assessment of Cochlear Size and Shape from Clinical CT Images. (ENG TR.004)https://doi.org/10.17863/CAM.55677
There is considerable interpersonal variation in the size and shape of the human cochlea, with evident consequences for cochlear implantation. The ability to characterize a specific cochlea, from pre-operative computed tomography (CT) images, would allow the clinician to personalize the choice of electrode, surgical approach and post-operative programming. In this study, we present a fast, practicable and freely available method for estimating cochlear size and shape from clinical CT. The approach taken is to fit a template surface to the CT data, using either a statistical shape model (SSM) or a locally affine deformation (LAD). After fitting, we measure cochlear length, mean lumen area and a novel measure of basal turn non-planarity, which is expected to correlate with the risk of insertion trauma. Gold-standard measurements from a convenience sample of 18 micro-CT scans are compared with the same quantities estimated from low resolution, noisy, pseudo-clinical data synthesized from the same micro-CT scans. The results show that the LAD method outperforms the SSM method, with an expected error of around 11% of the gold-standard sample range for non-planarity and cochlear length. Results for lumen area are significantly worse, reflecting the difficulty of detecting the cochlear inner wall in clinical CT.
cochlear implantation, pre-operative CT, model-based segmentation, cochlear size and shape
This record's DOI: https://doi.org/10.17863/CAM.55677
This record's URL: https://www.repository.cam.ac.uk/handle/1810/308590