CT三维重组诊断寰枢关节不全脱位的实验及临床研究

目的 比较寰枢关节的影像检查方法及技术，评价CT三维重组（CT3D）诊断寰枢关节不全脱位的临床价值。方法 实验研究寰枢关节骨标本1套，模拟出寰枢关节正常及脱位的模型，进行X线、常规CT及CT3D检查。前瞻性分析影像学特点及诊断准确率。临床患者87例进行中立位CT3D检查，其中28例加行左、右旋转位。分析CT3D显示脱位征象的特点及诊断寰枢关节不全脱位的临床效果。结果 实验组CT3D能清楚、直观的显示寰枢关节不全脱位各种征象，诊断准确率达100％。表面阴影法（SSD）CT3D显示寰枢外侧关节面错位最清楚，寰椎下关节面错位程度测量值与标本测量值差异无统计学意义（P〉0．05）。87例患者中诊断为寰枢关节不全脱位72例，其中旋转型脱位52例，前脱位13例，后脱位7例。中立位显示寰枢外侧关节面错位72例，旋转位显示为旋转固定8例，旋转不对称15例。结论 CT3D能显示寰枢关节不全脱位的各种征象，特别是寰枢外侧关节面错位。其中SSD法3D较X线、常规CT的诊断准确率高，具有成为诊断寰枢关节不全脱位金标准的条件。

Experimental and applied study of CT 3D-reconstruction in diagnosing atlantoaxial subluxation

Objective To compare the imaging examination and technique of atlantoaxial joint, and evaluate CT three-dimensional (3D) reconstruction in diagnosing atlantoaxial subluxation and find out the best way of 3D imaging. Methods In experimented study, one dry atlas (C1) and axis (C2) vertebral specimen were chosen and simulated as the models of normal atlantoaxial joint and atlantoaxial subluxation. All the models of specimen were examined by X-ray, CT scan and CT 3D. The imaging characteristic and diagnostic accuracy were prospectively analyzed. In clinical study, 87 cases were examined by CT-3D in neutral position, 28 of whom in additional rotary position. The characteristic in showing dislocation signs and effectiveness in diagnosing atlantoaxial subluxation of CT 3D were retrospectively analyzed. Results Our experiment shows that CT 3D imaging can demonstrate signs of atlantoaxial subluxation directly and clearly. Its diagnostic accuracy was 100%, and SSD imaging shows articular facets dislocation of lateral atlantoaxial joints most clearly in the technique of CT 3D. There is no significant difference between the dislocated measurement of inferior articular surface of atlas vertebral on specimen models and on SSD 3D-images(P>0.05). In the 87 cases, diagnosis of dislocation was obtained in 72, of whom rotary dislocation in 52, anterior dislocation in 13, posterior dislocation in 7. In neutral position, there is articular facets dislocation of lateral atlantoaxial joints in 72 cases, in rotary position, there is rotatory fixation in 8 and rotational asymmetry in 15. Conclusion CT 3D imaging can clearly show all the signs of atlantoaxial subluxation, especially articular facets dislocation of lateral atlantoaxial joints. Diagnostic accuracy of CT 3D is higher than those of X-ray and CT scan. CT 3D is eligible to be the golden standard in diagnosing atlantoaxial subluxation.