CT三维成像观察正常寰枢关节功能位的解剖学研究

目的:利用CT三维成像观察正常寰枢关节功能位的解剖结构,为诊断寰枢关节不全脱位探讨解剖学基础。方法:对53例正常志愿者进行中立位寰枢关节三维成像,其中21例加旋转位。三维重建方法以表面遮盖法(surface shade display,SSD)为主,辅以多层面重建法(mutiplanar reformatting,MPR)、最大强度投影法(maximum intensity project,MIP)、容积重建法(volume rendering,VR)。分析、比较其图像表现及解剖学特点。结果:53例中立位三维图像显示寰枢外侧上、下关节面基本对齐,寰齿关节间隙为1.0~3.3 mm;齿突侧距不对称24例,占45.28%。21例旋转位显示寰枢外侧上、下关节面呈旋转性关节面移位,移位宽度为5.76~8.18 mm,关节面吻合面积缩小约1/2~2/3,寰齿关节间隙大小无变化。齿突侧距对称者齿突偏向旋转侧,不对称者齿突偏移程度减轻或无改变。结论:CT三维成像能清楚显示寰枢关节功能位的解剖结构。观察到的功能位寰枢关节变化规律,为诊断及治疗寰枢关节不全脱位提供了理论依据。

Anatomic study on normal atlanto-axial joint in the functional position by using CT three-dimensional imaging method

Objective:To observe anatomic structure of normal atlanto-axial joint in the functional position by using CT three-dimensional imaging(3D) method,and to establish anatomic foundation for the diagnosis of atlanto-axial subluxation.Methods:Fifty-three persons volunteered to do CT-3D examination with atlanto-axial joint in the functional position,and examinations with atlanto-axial joint in rotary position were added to 21 patients.3D-images were mainly obtained by surface shade disply (SSD) method,assisted by multiplanar reformorting(MPR),maximum intensity project(MIP) and volume rendering(VR) methods.The imaging results and anatomic characteristics were analysed and compared.Results:The CT imaging with atlanto-axial joint in the functional position showed that the articular faces of lateral atlantoaxial joint had basic contraposition,the width of atlant-dens interval(ADI) ranged from 1.0 to 3.3 mm,and the lateral atlant dental space(LADS) deviated in 24 patients(45.28%).The CT imaging with atlanto-axial joint in the rotary position showed that the width of ADI had no changes,the articular faces of lateral atlanto-axial joint had rotary displacement with the width ranging from 5.76 to 8.18 mm,and anastomosis area of articular surface decreased by 1/2 to 2/3.The condyles had deflected to the rotary direction in the patients with symmetrical LADS,and to the patients with symmetrical LADS,the condyle deflected slightly or had no changes.Conclusion:CT 3D imaging can clearly show the anatomical structure of normal atlanto-axial joint in functional position.The rules of atlanto-axial joint movement which are observed in the present study lay theoretical basis for diagnosing and treating atlanto-axial subluxation.