齿状突先天畸形的MRI诊断

目的：利用ＭＲ的多平面成像和对软组织分辨率高的特点，为诊断齿状突先天畸形提供直接征象。材料与方法：在观察１００例正常齿状突ＭＲＩ表现以及复习一些径线测量和正常值的基础上，对５２例齿状突先天畸形的ＭＲＩ表现进行了分析。结果：５２例中发现齿状突不联合１６例，包括纵向不联合３例，横向不联合１３例（１１例伴寰枢关节脱位）；钩状齿状突２２例；固定性寰枢关节脱位１４例。神经组织改变包括颈髓或延髓受压４３例（８３％），Ｃｈｉａｒｉ畸形２６例（５０％）和脊髓空洞１２例（２３％）。结论：与Ｘ线及ＣＴ相比，ＭＲＩ能更明确显示齿状突的结构、位置改变，以及神经组织受压程度和伴发的其他畸形，从而为拟定治疗方案提供精确信息。但对可复性脱位的诊断不如常规Ｘ线和ＣＴ检查。

MRIdiagnosisincongenitalanomalyoftheodontoidprocess

Purpose:ToevaluateMRIinthediagnosisofcongenitalanomaliesoftheodontoidprocess.Materialsandmethods:Onthebasisof100casesofnormalodontoidprocessstudiedandmeasuredwithMRI,analysiswasdoneon52casesofcongenitalanomaliesofodontoid.Results:Unfusedodontoidprocesswasfoundin16casesincludingbifiddens,3cases;transversenon-union13casses(11ofwhichwereassociatedwithatlanto-axialdislocation);hookeddens22cases,fixedatlanto-axialdislocation14cases.Compressionofspinalcordormeduleoblongatawasseenin43cases(83%),whileChiarimalformationwasfoundin26cases(50%)andsyringomyeliain12cases(23%).Conclusion:MRIissuperiortoX-rayorCTindemonstratingthestructureanddisplacementofodontoidprocesaswelascompressionofthenervoustisuemoreindetail.However,indiagno-sisofreducibledislocation,X-rayandCTarebeter