| ObjectiveOur goals are to study the normal microanatomic information of the craniocervical junction region by using magnetic resonance imaging and thin-slice sectional anatomic techniques, to describe the lower cranial nerves and the suboccipital cavernous sinus's relationship to their surrounding blood vessels, to build the 3D reconstruction model and to obtain the normal sectional anatomical data of the glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve, the suboccipital cavernous sinus and their related blood vessels, for providing the morphological basis for clinical image diagnosis and skull base approaches.Methods 1.260 healthy volunteers (130 males and 130 females, whose ages ranged from 3 to 89) were studied using a 1.0-tesla MR imaging system, underwent FLASH-3D gradient echo technique MR imaging. Each section was 1.0 mm in thickness. Meanwhile, the lower cranial nerves, the suboccipital cavernous sinus and their surrounding structures were multi-directionally reconstructed with MPR. 2. The skull base blocks were obtained from ten human cadavers. A plastination technique was used to make equidistant serial thin sections on the coronal, sagittal, and axial planes with 1.0mm in thickness, comparing with the images of MRI.3. After undergoing macroscopical, CT and MRI examinations to exclude organic lesion, a middle-aged male cadaver was selected as the subject. Morphological measurement and vascular perfusion was performed. Embedded with 5% gelatin, the cadaver was immersed in saline pool and frozen to -30℃ for 1 week. TK-6350 numerical control milling machine (milling accuracy of 0.001mm) was used to shave off slices of the body layer by layer from head to foot at -25℃ in low temperature laboratory. The successive cross-sections were photographed with high-resolution digital camera and scanned into an animation computer. Thus, data acquisition from cadaver-model was completed to obtain structural data set of human body. Chosen layers from 257 to 329 of this first data set of Chinese visible human for the craniocervical junction region's study. 4. On SGI workstation, a Contours + Marching Cubes algorithm was selected to reconstruct the glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve, the suboccipital cavernous sinus and their related blood vessels in three-dimensions. The improved Medview 1.0 software was used to convert the mcb format of the 3-D data to STL format, then the STL file input into the rapid apparatus ZIPPY III, the 3D stereo physical model of the craniocervical junction region was built.Results　1. All the evaluated structures of the craniocervical junction region were seen routinely in all three planes on MR images. In the 120 volunteers examined using FLASH-3D gradient echo technique, we identified the glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve in their complete cisternal course in the axial plane. The lower cranial nerves had a close relationship with the vertebral artery, posterior inferior cerebellar artery and anterior inferior cerebellar artery. In the 140 volunteers examined using multiplanar reconstruction (MPR), contrast-enhanced, T1-weighted MR sequences and evaluated the following vascular structures: the suboccipital cavernous sinus, marginal sinus, anterior condylar vein, posterior condylar vein,vertebral artery, vertebral venous plexus and vertebral artery venous plexus. The suboccipital cavernous sinuses, known to be variably present, the average left-side size was 8.05±1.49mm and the right one was 7.91±1.38mm. There was no statistically significant difference between the two sides (P>0.05). The vertebral artery venous plexus, suboccipital cavernous sinuses,and anterior condylar vein showed the least variation from person to person; the posterior condylar vein and vertebral venous plexus showed the most.2. Ten thin serial plastinated slices of 1.0mm in thickness of axial, coronal, and sagittal orientations were obtained. The impregnation with epoxy resin results...
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