This 3-D virtual model of a human temporal bone is a powerful teaching tool for learning the complex anatomy of the human temporal bone and for relating the 2-D morphology from a histological section to the 3-D anatomy. The model was created from archival histological sections from a 14-year old male. The specimen was formalin fixed, decalcified, embedded in celloidin, serially sectioned in the axial plane at 20 microns, stained with hematoxylin and eosin, and mounted on slides. Low-power views of every fifth section through the temporal bone were digitized and imported into Amira v3.1 (Mercury Computer Systems/TGS, San Diego, CA). The sections were aligned and segmented into anatomical "structures of interest".
The 3-D model is a surface rendering of these structures of interest, which currently includes (among others) the bone and air spaces of the temporal bone; the perilymphatic and endolymphatic spaces including cochlear aqueduct and endolymphatic duct and sac; the sensory epithelia of the cochlear and vestibular labyrinths; the ossicles and tympanic membrane; the middle-ear muscles; the carotid artery; and the auditory, vestibular and facial nerves. For each of these structures, the surface transparency can be individually controlled, thereby revealing the 3-D relations between surface landmarks and underlying structure. New structures of interest can be added within the Amira software.
The 3-D surface model can also be "sliced open" at any section, and the appropriate raw histologic image superimposed on the cleavage plane. Leafing through the section stack in this way provides a powerful view of the relation between microscopic images and 3-D anatomy. The image stack can also be re-sectioned in any arbitrary plane.
The alignment of the temporal bone structures to the
skull was based on the measurements of the averaged orientations and
centroid positions of the semi-circular canals provided in the paper
Orientation of Human Semicircular Canals Measured by Three-Dimensional
Multiplanar CT Reconstruction (Della Santina et al. JARO 6:191
The model was made under the supervision of Drs. M. Charles Liberman and Saumil Merchant by Haobing Wang and Clarinda Northrop. Model development was supported by a core grant from the NIDCD (P30 DC05209).
Screen shots of 3-D model of Human Temporal Bone displayed In freeware EPL 3-D viewer