CT三维成像诊断寰枢关节不全脱位的临床价值

目的 评价CT三维成像对寰枢关节不全脱位的显示及诊断价值，探讨最佳三维成像方法。方法回顾性分析41例寰枢关节不全脱位的CT影像学表现，比较横断面图像、多层面重建(multiplanar reformatting，MPR)法、表面遮盖(surface shade display，SSD)法、最大强度投影(maximum intensity projection，MIP)法及容积重建(volume rendermg，VR)法三维图像显示的病变情况。结果寰枢关节不全脱位41例，其中旋转型脱位31例，前脱位5例，后脱位5例。影像学表现为上、下关节面错位41例，其中错位2～5mm 29例、5～9mm 12例；齿突侧距不对称15例；寰齿间隙增宽合并骨折8例。SSI)法三维影像直观显示移位的寰枢关节上、下关节面，齿突侧距不对称及寰齿间隙增宽；横断面图像和MPR、MIP及VR法三维图像显示移位的上、下关节面差、不直观。结论运用CT三维成像能准确显示及诊断寰枢关节不全脱位，并以SSD法三维成像最佳。

Application of CT three-dimensional reconstruction in diagnosing atlantoaxial subluxation

Objective To evaluate the diagnostic value of CT three dimensional (3D) reconstruction in atlantoaxial subluxation and point out the best way of 3D reconstruction. Methods 3D reconstruction findings of 41 cases with atlantoaxial subluxation were retrospectively analyzed so as to make comparisons with the traverse images and the pathologic changes detected by means of multiplanar reformatting (MPR), surface shade display (SSD), maximum intensity projection (MIP) and volume rendering (VR). Results Of 41 cases with atlantoaxial subluxation, 31 had rotary dislocation, five anterior dislocation and five posterior dislocation. The images showed 41 cases of dislocated joint panel, of which 29 with dislocation for 2 5 mm and 12 for 5 9 mm. There were 15 cases with deviation of the odontoid process and 8 with widened atlantodentilis. SSD showed directly the upper and lower surface of the altanto axial joint, the deviation of the odontoid process and the widened atlantodentilis. The traverse images and the images of MPR, MIP and VR showed poor dislocation. Conclusion Atlantoaxial subluxation can be displayed and diagnozed by 3D reconstruction, especially SSD.