正常寰枢间放射学测量及临床意义

通过对１２０ 名正常国人寰枢椎放射学测量，提供临床放射学意义。拍摄颈椎侧位屈曲位，伸展位和中立位Ｘ光片，测量３ 项指标：寰齿间距（ＡＤＩ） ，脊髓有效间隙（ＳＡＣ） 和脊髓有效间隙变化率即不稳定指标（ＩＩ） ，所得结果进行统计学分析。测量结果，正常成人ＡＤＩ中立位、屈曲位、伸展位分别为１ ．３６ ±０ ．６２（ｘ ±Ｓ，下同）ｍ ｍ ，（１．３１ ±０ ．６８）ｍ ｍ 和（１ ．３５ ±０ ．７５）ｍ ｍ 。ＳＡＣ分别是（２０ ．３ ±１ ．１）ｍ ｍ ，（２０ ．１ ±０ ．９）ｍ ｍ ，（２０．４ ±１ ．３）ｍ ｍ 。ＩＩ为（１１ ．８５ ±４ ．５６） ％ 。结果提示ＡＤＩ≥４ ｍ ｍ 时即可诊断寰枢椎不稳，≥３ ｍ ｍ 时应高度怀疑寰枢椎不稳。ＳＡＣ≤１４ ｍ ｍ 可论断Ｃ１ 平面椎管狭窄。ＩＩ≥２２ ％ 即有临床诊断意义。

Normalatlantoaxialradiographic measurement and clinicalsignificance

To provide atlantoaxialradiographic measurement and clinicalsignificance- Method :Cervicalplainlateral radiographs were taken in neutral,flexior and extension position-Three parameters were measured : The atlanto dentalinterval(ADI) ,thespace availableforthespinalcord(SAC) ,thechange ofspaceavailableforthespinalcord from flexion to extension (Instability Index)-The mesurementresults werestatistically analyzed-Results:The nor maladult ADIin neutral,flexion and extension position were (1 .36 ±0 .62) m m (meant standard error of the mean) ,(1 .3 ±0 .68)m m ,and (1 .35 ±0.75)m m-The SACwere (20 .3 ±1 .1)m m ,(20 .1 ±0.9)m m ,(20 .4 ±0 . 9)m m ,(20.4 ±1 .3)m m-The averageinstabilityindex was (11 .85 ±4 .56) % -Conclusion :It wassuggested that theatlantoaxialinstability should be diagnosised when ADI≥4 m m in adult,the ADIexceeding 3 m m raises a strang suspicion-The spinalstenosisin C1 plain should be diagnosed when SAC≥14 m m-There wasclinicaldiagnos ticsignificanceifaninstabilityindex of morethan 22 % -