颅底凹陷症和寰枕融合畸形是枕大孔区常见的两种畸形，ＣＴ能直观显示二者骨结构的改变，较常规Ｘ线检查具有较大的优越性，为了判断寰椎及枕髁的发育程度，颅底凹陷是否存在，我们设计并测量了有关径线。１材料和方法随机抽取２００例无颈、延髓症状的正常人，男１０６例... Skull base depression and atlanto-occipital fusion deformity is a common foramen magnum two deformities, CT can intuitively show the two changes in bone structure, compared with conventional X-ray examination has greater superiority, in order to determine atlas and occipital condyle The degree of development, the existence of skull base depression, we designed and measured the diameter of the line. 1 Materials and Methods 200 cases of non-neck, medullary symptoms of normal, male 106 cases ...