Imaging Microstructures of Mouse Inner Ears in Situ by Phase Contrast Micro-CT

Objective: Aim of the study was to image the mouse inner ears in situ by phase contrast Micro-CT, and explore the ability of this technique to display the microstructures. Method: The experiment was performed according to our institution's guidelines on the care and use of laboratory animals. An adult mouse was anesthetized and sacrificed, followed by phase contrast Micro-CT scan for both inner ears. The CT data sets were reconstructed using the filtered back-projection (FBP) algorithm. Different pixel-size CT images, including 9 μm, 18μm, 36 μm, 54 μm and 72 μm, were obtained after image processing. Results: The CT images of 9 μm pixel size visualized clearly the microstructures of inner ears, including modiolus, osseous spiral lamina, utricular macula and saccular macula. The edge sharpness of the microstruetures was decreasing when the pixel size of the images became bigger. The CT images of 18~tm and 36 ktm pixel size also displayed all of the microstructures. The microstructures were seen in the CT images of 54μm pixel size, but their edges were blurry. The CT images of 72~m pixel size showed an indistinct outline only of the modiolus and osseous spiral lamina, while the outline of utricular macula and saccular macula was not observed. Conclusion: Phase contrast Micro-CT was demonstrated to have the potential to visualize the microstructures of mouse inner ears in situ.