探讨运用螺旋CT制定寰枢关节脱位的影像学诊断标准

Investigation on the use CT to make diagnostic radiographic criteria for atlanto-axial dislocation

目的:分析正常人群、寰枢关节脱位患者的薄层螺旋CT表现,筛选出最有效的诊断指标,制定寰枢关节脱位的影像学诊断标准。方法:收集颈椎正常人群(n=501)、寰枢关节脱位患者(n=51)的薄层螺旋CT资料,测量比较2组寰齿前间隙(anterior atlanto-dental interval,AADI)、寰齿后间隙(posterior atlanto-dental interval,PADI)、寰枢椎垂直脱位指数(vertical atlanto-axial index,VAAI)、寰枢侧方间隙(lateral mass interval,LMI)、寰枢椎相对旋转角度(rotating angle of atlas on dentata,RAAD)、齿突侧方间隙(lateral atlanto-dental interval,LADI)、寰枢椎侧方距离差、寰枢关节侧方成角多个参数,统计各型寰枢关节脱位例数并进行统计学比较。结果:寰枢关节脱位组,AADI、LADI、侧方成角均大于颈椎正常组;PADI、VAAI、LMI均小于颈椎正常组,差异有统计学意义(均P<0.01)。AADI(0.795)、PADI(0.825)、VAAI(0.821)、LADI(0.890)的ROC曲线下面积大,诊断价值高。若满足下列任意一项,高度提示寰枢关节脱位:AADI≥2.2 mm、PADI≤15.4 mm、VAAI≤0.65、LADI≥4.4 mm。寰枢关节脱位的类型中,前后脱位7例(13.7%),垂直脱位11例(21.6%),旋转脱位1例(2.0%),侧方横向平移脱位2例(3.9%),侧方成角脱位1例(2.0%),复合脱位29例(56.9%)。结论:AADI、PADI、VAAI、LADI为诊断寰枢关节脱位高有效性指标,根据测量结果对寰枢关节脱位分型,采取合理的方法进行治疗具有重要意义。

Objectives：To investigate the differences of the CT images between normal people and patients with atlanto-axial dislocation,and to scree the most effective radiographic diagnostic indexes.Methods：The CT images of the normal people（n=501）and the atlanto-axial dislocation patients were collected.The anterior atlantodental interval（AADI）,posterior atlantodental interval（PADI）,vertical atlantoaxial index（VAAI）,lateral mass interval（LMI）,rotating angle of atlas on dentata（RAAD）,lateral atlanto-dental interval（LADI）,lateral mass overhang distance,atlanto-axial lateral mass rotating angle of two groups were measured.The various types of the altanto-axial joint dislocation were counted and the statistical analysis was made.Results：AADI,LADI,atlanto-axial lateral mass rotating angles were higher in atlanto-axial dislocation group than in normal group.PADI,VAAI,LMI were lower in atlanto-axial dislocation group than in normal group with significant differences（P〈0.01）.The area under ROC curve of AADI（0.795）,PADI（0.825）,VAAI（0.821）,LADI（0.890） were high indicating high diagnostic value.If measured value met the following items,it prompted atlanto-axial dislocation：AADI≥2.2 mm,PADI≤15.4 mm,VAAI≤0.65,LADI≥4.4 mm.Conclusion：AADI,PADI,VAAI,LADI,atlanto-axial lateral mass rotating angles are the most effective diagnostic indexes of atlanto-axial dislocation.According the measured diagnostic results,it is important for a surgeon to chose the reasonable treatment.