Three-Dimensional Virtual Model of the Human Temporal Bone: A Stand-Alone, Downloadable Teaching Tool

Objective—To develop a three-dimensional virtual model of a human temporal bone based on serial histologic sections. Background—The three-dimensional anatomy of the human temporal bone is complex, and learning it is a challenge for students in basic science and in clinical medicine. Methods—Every fifth histologic section from a 14-year-old male was digitized and imported into a general purpose three-dimensional rendering and analysis software package called Amira (version 3.1). The sections were aligned, and anatomic structures of interest were segmented. Results—The three-dimensional model is a surface rendering of these structures of interest, which currently includes the bone and air spaces of the temporal bone; the perilymph and endolymph spaces; the sensory epithelia of the cochlear and vestibular labyrinths; the ossicles and tympanic membrane; the middle ear muscles; the carotid artery; and the cochlear, vestibular, and facial nerves. For each structure, the surface transparency can be individually controlled, thereby revealing the three-dimensional relations between surface landmarks and underlying structures. The three-dimensional surface model can also be “sliced open ” at any section and the appropriate raw histologic image superimposed on the cleavage plane. The image stack can also be resectioned in any arbitrary plane. Conclusion—This model is a powerful teaching tool for learning the complex anatomy of the human temporal bone and for relating the two-dimensional morphology seen in a histologic section to the three-dimensional anatomy. The model can be downloaded from the Eaton-Peabody Laboratory web site, packaged within a cross-platform freeware three-dimensional viewer, which allows full rotation and transparency control