Sagittal CT without contrast of the cervical spine (left) shows a large well-corticated ossicle posterior and superior to the anterior arch of C1 and superior to the dens, hypertrophy of the anterior arch of C1, and a large atlanto-dens interval due to atlanto-axial dislocation. Sagittal T2 MRI without contrast of the cervical spine (right) shows a narrow spinal canal secondary to the atlanto axial dislocation with spinal cord compression and abnormal bright signal in the spinal cord at C1-C2.
Pediatric Imaging 