Optical coherence tomography of the rat cochlea: Preliminary investigations

Optical coherence tomography (OCT) was used to image the internal structure of a rat cochlea (ex vivo). Immediately following sacrifice, the temporal bone of a Sprague-Dawley rat was harvested. Axial OCT cross sectional images (over regions of interest, 1×1 mm to 2×8 mm) were obtained with a spatial resolution of 10-15 μm. The osseous borders of the lateral membranous labyrinth overlying the cochlea and the scala vestibuli, media, and tympani which were well demarcated by the modiolus, Reissner's and the basilar membranes were clearly identified. OCT can be used to image internal structures in the cochlea without violating the osseous labyrinth, and may potentially be used to diagnose inner ear pathology in vivo in both animal and human subjects