| Recently, many studies about post processing methods of spiral CT of the temporal bone have been reported. The authors concluded that; these methods were considered a complementary technique to conventional CT, and providing better visional details of the complex structures of temporal bone; these techniques may have an important role in preoperative planning, surgical training and /or postoperative evaluation; Since the parameters of CT scanning and threshold of reconstruction plays an important role in visualization of the anatomic structure, It is necessary to have a comparison of reconstructed images and local anatomy.Hybrid rendering method ( color - coded 3 D shaded surface display and volume display) of temporal bone has not been reported in China until now. The aims of this study are as followed; first visualizing the important structure of temporal bone by hybrid rendering method; second, convincing that the reconstructive image is somewhat objective by comparing the reconstructive images with real structure of local anatomy; finally trying to have surgical training on the reconstructed tissue using the software of workstation.MethodSeven formalin - fixed cadavers were scanned with multiple spiral CT (Philips MX8000) The HRSCT scan parameters were: 120kv, 244mas,beam collimation 0. 6,Pitch 0. 875 and 512 512matrix,recon-struction increment 0. 2. After scanning was finish, each side of temporal bone was separately reconstructed with 90 mm field of view. The axial image data sets were transferred to a independent workstation (Silicon graphics 0. 2).Using a ossicle as a criterion to determine the window level and window width for ossicle SSD reconstruction. All the ossicles were reconstructed with this window level and window width. Structures of ossicles , facial nerve, sigmoid sinuses, and labrinthines were segmented using an interactive threshold interval density volume - growing method and visualized with a color - coded SSD rendering method. The temporal bone was visualizing using a transparent volume rendering method.On the workstation maximum length of incus of SSD reconstruction and distance between the sigmoid sinus and external auditory mea-tus and distance between sigmoid sinus and facial nerve at the middle level of the post wall of external auditory meatus of hybrid rendering images were measured.Finally, perform simulating surgery on reconstructed tissue according to the processes of surgery on cadavers.Each cadaver specimen was dissected and extended the dissection in order to expose the outline of sigmoid sinus, facial nerve and semicircular canal, dissection further to tympanic cavity to expose the ossicles and round window etc, after that, simulating operation were performed. According to the surgery through labrinthines. The length and the distance that had been measured on reconstructed tissue of workstation also were measured on the specimen using vernier caliper.ResultWith the hybrid rendering method, the structures of temporal bone could be seen in their complete form and correct topographical relationship which are same with the cadaveric specimen. Using statistic comparing the data measured on SSD reconstructed ossicles with that measured on specimen, t value is 0. 1174, 0. 20 >p >0. 10; For the statistical analysis of the date of the two distance measured on reconstructed tissue and measured on specimen, the data of two groups have very high relationship, r value are 0.957 and 0. 987 seperetive-ly. It is possible for otolaryngoligist to simulate some surgical processes on the workstation before operation.DiscussionHybrid rendering method of temporal bone has been studied by Seemann et al. The authors specifically highlighted the use in relation to the middle and inner ear structure. In our study, we pay more attention to morphologic relationship of the important vessel and nerve that are very important to the processes of surgery. By comparing the morphology and size measurement between the reconstructed images and specimen, we found that thi...
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