Abstract：Objective: To compare the features of imaging examination in the atlantoaxial joints, and evaluate imaging examination in diagnosing atlantoaxial subluxation. Methods: Fifty-two cases were examined by plain X-ray, 69 by routine CT, 7 by MRI, and 89 by CT three-dimensional(3D) imaging. Their imaging findings in diagnosing atlantoaxial subluxation were retrospectively analyzed, their imaging manifestations were observed and the imaging diagnosis obtained. 3D-images were mainly obtained by surface shade display(SSD), assisted with multiplanar reformorting(MPR), maximum intensity projection(MIP) and volume rendering(VR). Results: In the 52 cases examined by X-ray examination, there were 13 cases with dislocation, 17 cases were suspicious and negative in 22. In the 69 cases examined by routine CT, 32 cases had dislocation, suspicious in 23 and negative in 14. In the 7 cases examined by MRI, 1 case had dislocation, suspicious in 3 and negative in 4. In the 89 cases examined by CT-3D reconstruction, 72 cases had dislocation and negative in 17. Its positive diagnostic rate of dislocation and diagnostic rate of rotary dislocation is 80.9% and 72.2% respectively. Conclusion: Imaging examinations are the main methods in diagnosing atlantoaxial subluxation, and can be used in ascertaining diagnosis. 3D-CT shows the signs of atlantoaxial dislocation most clearly and directly.
2006, Vol. 17 
