Resluts All the 14 cases showed clivus projecting intracranial.posterior displacement of Odontoid Process were found in 3 cases,with 1 case of Atlanto-occipita fusion malformation.

14MR矢状位像均显示斜坡向颅内陷入,3状突后移,1并寰枕形,14均清晰地显示了延颈髓的形态及与小脑扁桃体的关系。