Os Odontoideum

  • Etiology:
  • Imaging: (radiograph, CXR, AXR, US, CT, MRI)
  • DDX:
  • Complications:
  • Treatment:
  • Clinical:

Radiology Cases of Os Odontoideum

CT of os odontoideum
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.