BACKGROUND: Posterior atlantoaxial fusion with internal fixation is a common treatment method for the treatment of upper cervical lesions. Some cases of vertebral artery injuries have been reported since complex and variable anatomical structure here.
OBJECTIVE: To observe normal three-dimensional CT angiograph images of the upper cervical spine and to study the anatomy of atlantal posterior arch and the accompanying vertebral artery journey in order to provide the basis of microvascular anatomy for clinical treatment.
METHODS: Four hundred cases without pathological lesions of atlantoaxial joint were selected. All the three-dimensional CT images were formed with volume rendering together with the techniques of separating, fusing, opacifying and false-coloring, On the three-dimensional CT images, the courses and variations of vertebral artery were observed, and the posterior screw-related data of the atlantal posterior arch were measured.
RESULTS AND CONCLUSION: All the three-dimensional CT angiography images of head and neck were in high quality and up to our requirements. The courses of vertebral artery accompanied with the atlas were curved. There were 385 cases with typical itinerary. Variations were found in 15 cases, a total of 18 sides. There were 11 sides of persistent first intersegmental artery, 6 sides of fenestrated vertebral artery, 1 side of abnormal posterior inferior cerebellar artery respectively. 48 cases of posterior ponticulus were found, and 10 cases were bilateral, a total of 58 sides. The bottom of the vertebral artery’s groove was the weakest part of the posterior arch, and there was no significant difference between left and right (P > 0.05). The shape of the atlantal posterior arch and the vicinal vertebral artery are polytropic which bright the uncertain factors for the atlas posterior screw. Therefore, the three-dimensional CT angiography image clearly shows the anatomical structures. Full understanding of these data before operation can help to identify the precise surgical programs in order to improve the security of the operation.