Virtual CT otoscopy of the middle ear and ossicles in dogs

Virtual otoscopy enables noninvasive 3D endoluminal imaging of the middle ear through postprocessing of computed tompgraphy (CT) data. A standardized imaging approach for the middle ear was established in six normal dogs in an attempt to optimize the clinical application and student education. High-resolution CT data were obtained. Virtual otoscopic images of the middle ear cavity and ossicles were generated using commercially available software. The views of the four different directions (the ear canal, tympanic bulla, eustachian tube, and ossicular chain) were made for virtual otoscopy. The promontory, cochlea window, tympanic bulla, septum bulla, and auditory tube were distinguished easily and clearly. One of the ossicles, the malleus, was visualized accurately. However, small structures such as the incus and stapes always could not be seen. The main advantage of virtual otoscopy is not only to provide diagnostic information but also to enhance the quality and efficiency of student education, because it contributes to an understanding of the anatomy of the middle ear. We describe the normal topographical 3Dimages of the middle ear of the dog using virtual otoscopy.