Anatomic Study Of Intratemporal Structures And Computer-aided Three-dimensional Reconstructed Images

Objective The microanatomy of intratemporal structures and computer-aided three-dimensional reconstructed images were studied by using various methods in order to provide anatomic basis for otolosurgery and neurosurgery. Methods (1)We observed and measured Osseous structures of the temporal bones in 30 skulls, the structures passing the internal auditory meatus, cerebellopontine angles and the facial canals in 15 adult cadaveric heads, the plastic models of bony labyrinth in 30 skulls and 2D images spiral CT of cochlea nerve canals in 10 skulls under macro-microscopy and Voxel Q CT working station.(2)3D images spiral CT in 8 sides of volunteers including MPR,SSD and CTVE, 3D images of inner ear by using maximum intensity projection and 3D images of intratemporal structures by using the Chinese visible human data set were performed and measured under computer working station.Results (1)The configuration of internal auditory pore was oval shape in 83.3% of all and there were suprameatal tubercle in 25.0%. The distances from internal auditory pore to the external aperture of the vestibular aqueduct and to posterior semicircular canal were 9.71 1.38mm and 15.62 2.40mm.(2)The distance between hiatus of facial nerve canal and the projecting point of fundus of internal auditory meatus was 8.04+ 2.01mm.(3)The satisfactory plastic models of bony labyrinth were obtained. Among them, the span of anterior bony semicircular canal was the longest, and the internal diameter of lateral bony semicircular canal was the boldest; and the height and the arc length of posterior bony semicircular canal were the longest.(4)The cochlea nerve canal was scanned by spiral CT and the reference value of the diameter of cochlea nervecanal was in the range from 2.08mm to 2.23mm.(5)The labyrinthine portion of facial nerve canal was the narrowest. (6)The satisfactory MPR images of cochlea, bony semicircular canals, internal auditory meatus and other intratemporal structures might be obtained by different slices. The SSD images could show the important bony marks of temporal bone and the spatial relationships between them perspicuously. The coronal dissected images of SSD can vividly demonstrate the shape and the spatial relationships of malleus and incus. A series images were obtained as the virtual endoscope moved from the external auditory canal to the middle ear cavity. Vritual endoscopy could well demonstrate the surface of medial wall and ossicles.(7)Anatomic structures of internal auditory meatus and membraneous labyrinth were well demonstrated in all volunteers. With T2 weighted 3D-FSE sequence, all three semicircular ducts, utricle, saccule, cochlea duct and internal auditoruy meatus produced high singal intensity.(8)The 3D images of intratemporal structures could be obtained on SGI working station. All structures reconstructed could be represented individually or jointly and rotated continuously in various planes. Conclusions (1)Internal auditory pore can be served as landmark for otolosurgery and neurosurgery.(2)The hiatus of facial nerve canal was important landmark to define internal auditory meatus. (3) Three bony semicircular canals were not same in appearance and size.(4)The number range of CT diameter of cochlea nerve canal was helpful for choosing the method in cochlea implantation.(5)To be familiar with the microanatomy of the facial nerve in internal auditory meatus, cerebellopontine angles and the facial canal is helpful for localizing the facial nerve and improving its preservation in otolosurgery and neurosurgery.(6)The images of spiral CT including SSD, MPR and CTVE can enrich the diagnostic information for observer. The reconstructed images can be used to design tactics for otolosurgery and be applied in medical education.(7)MIP images might document, stereoscopically and directly, the minute structures of internal auditory meatus and membraneous labyrinth. For the firsttime, the MRI measurement's criterion of inner structures is established.(8)All structures reconstructed can be represented indi...