Abstract

Conclusion: The use of both gadolinium chloride (GdCl₃) and osmium tetroxide (OsO₄) allowed for the visualization of the membranous labyrinth and other intralabyrinthine structures, at different intensities, as compared with the control sample. This initial comparison shows the advantages of GdCl₃ in radiological assessments and OsO₄ in more detailed anatomical studies and pathways of labyrinthine pathogenesis using X-ray microtomography (microCT). Objective: To assess an improved OsO₄ staining protocol and compare the staining affinities against GdCl₃. Methods: Guinea pig temporal bones were stained with either GdCl₃ (2% w/v) for 7 days or OsO₄ (2% w/v) for 3 days, and scanned in a microCT system. The post-scanned datasets were then assessed in a 3D rendering program. Results: The enhanced soft tissue contrast as presented in the temporal bones stained with either GdCl₃ or OsO₄ allowed for the membranous labyrinth to be visualized throughout the whole specimen. GdCl₃-stained specimens presented more defined contours of the bone profile in the radiographs, while OsO₄-stained specimens provided more anatomical detail of individual intralabyrinthine structures, hence allowing spatial relationships to be visualized with ease in a 3D rendering context and 2D axial slice images.