Abstract: Objective: To provide a valuable imaging anatomic method for operation of tympana and accurate positioning among relative structures in operation. Methods: The clinical information of 112 adult cases(224 sides)was analyzed. All the underwent CT scaning and three-dimensional image reconstruction of skull base. Axial and coronal images were reconstructed using multiplanar reconstruction technique of station and the anatomic objective structure were displayed by rotating imaging slices. The data were analyzed in statistically and compared with the published cadaver data. Results: The distance from the chochleariform process to the horizontal portion of facial nerve recess(C), the shortest distance from the pyramidal eminence to the pyramid segment of the facial canal(D), inner diameter (E)and outer diameter(F) of facial recess, inner diameter (G)and outer diameter(H) of sinus tympani, the shortest distance from the head of stapes to the horizontal portion of facial nerve recess(N), the shortest distance from the stapedial footplate to the horizontal portion of facial nerve recess(O), among the different genders have significant(P＜0.05). The left distance from the anterior wall of sigmoid sinus to the posterior wall of extemal auditory meatus(A), the distance from the lateral wall of sigmoid sinus to the surface of mastoid process(B), the vertical distance from the lateral semicircular canal to the jugular bulb(Q) are greater than right, among the different sides have significant(P＜0.05) There were no significant differences between imaging quantitative measurement and published cadaver data(P＞0.05). Conclusions: The result of three–dimensional quantitative measurement by using multiplanar reconstruction could represent a real distance of anatomic structures. It may provide a valuable method for surgical approach and accurate positioning of relative structure in operation.

Key words: Tomography, Skull, Anthropometry, Multiple reconstruction, Anatomy