Application of CT 3D reconstruction in diagnosing atlantoaxial subluxation.

Objective:To evaluate and compare the diagnosti c value in atlantoaxial subluxation by CT three-dimensional (3D) reconstruction . Methods:3D reconstruction findings of 41 patients with atlanto axial subluxation were retrospectively analyzed, and comparisons were made among images of transverse section, multiplanar reformorting (MPR), surface shade dis play (SSD), maximum intensity project (MIP), and volume rendering (VR). Results:Of 41 patients with atlantoaxial subluxation, 31 belon ged to rotary dislocation, 5 antedislocation, and 5 hind dislocation. All the ca ses showed the dislocated joint panel of atlantoaxial articulation. Fifteen case s showed deviation of the odontoid process and 8 cases widened distance between the dens and anterior arch of the atlas. The dislocated joint panel of atlantoax ial articulation was more clearly seen with SSD-3D imaging than any other metho ds. Conclusions:Atlantoaxial subluxation can well be diagnosed by CT 3D reconstruction, in which SSD-3D imaging is optimal.