Evaluation of the structure of the otoconial layer using micro-computed tomography

Objective: Estrogen deficiency caused by bilateral ovariectomy (OVX) has been reported to lead to morphological changes in otoconia. Thus, we examined the morphological changes in the otoconial layer after OVX. We also investigated whether micro-computed tomography (mu CT) is useful for the detection of morphological changes in the otoconial layer. Methods: The otic capsules of C57BL/6 J mice were removed and evaluated using histological techniques and mu CT at 2, 4, and 8 weeks after OVX or sham surgery. The volume of the utricle otoconial layer was measured and compared between the OVX and sham groups. The mu CT scan and histological study results were also compared. Results: The volume of the utricle otoconial layer was significantly increased 4 weeks after OVX compared to the sham group in both histological and mu CT studies (p < 0.05). The volume of the otoconial layer measured using mu CT was significantly correlated with the histological study results (p < 0.05). Conclusion: The volume of the utricle otoconial layer increased after OVX. These morphological changes could be detected by mu CT. (C) 2020 Oto-Rhino-Laryngological Society of Japan Inc. Published by Elsevier B.V. All rights reserved.