Anatomy of the temporal bone : Detailed three-dimensional display based on image data from high-resolution helical CT : A preliminary report

Our purpose was to demonstrate the application of helical computed tomography (CT) for computer graphics of the normal temporal bone with special regard to inner ear structures. Three-dimensional reconstruction of temporal bones was performed from helical CT data on 41 patients with various otologic diseases. Image postprocessing was carried out on an independent work station. In contrast to former surface-rendered three-dimensional visualizations of the temporal bone, a volumetric-rendering algorithm was used. This technique allows automated segmentation, thresholding, and simultaneous visualization of different planes (cube-cutting) in near-real time. We were able to demonstrate the three-dimensional display of the labyrinth during clinical routine. Anatomic details (internal auditory canal, cochlea, vestibulum, semicircular canals, distal part of the vestibular aqueduct, complete ossicular chain, fallopian canal, internal carotid canal) were comprehensively demonstrated by interactive segmentation or thresholding. Difficulties were found in three-dimensional delineation of the complete vestibular and cochlear aqueduct, as well as the modiolus. Initial experience with an advanced helical CT-based three-dimensional display showed excellent images of temporal bone anatomy. Validation studies with correlative histologic sections and surgical dissections remain to be done.