CVJ is a collective term that refers to the occiput, atlas, axis, and supporting ligaments. It encloses the soft tissue structures of the cervicomedullary junction.

Includes:

The caudal portion of the brainstem (Medulla)

Cerebellum

Fourth ventricle

The rostral part of the spinal cord

Lower cranial & upper cervical nerves

• CVJ is divided into two components concerning the governance of inter-segmental movements:
  

  Fig 1: CVJ Anatomy Sagittal MRI (A) & CT (B) images : showing relationship of odontoid to adjacent osseous and soft tissue structures : C-2 vertebrae(1), anterior arch of atlas (2), posterior arch of atlas (3), clivus (4), opisthion (5) , basion (6), sella (7), nasion (8),cerebellum (9) ,cervical spinal cord (10), and medulla(11).

The central pivot: Dens and the C2 vertebral body & Basiocciput.

Two ringed structures: Foramen Magnum  & Atlantal ring

VIEWS & IMAGING ESSENTIALS:

Plain Radiographs

               lateral view

               AP  view

               Open-mouth odontoid  view

               Flexion / Extension views-  not  done in trauma 

CT :    Useful in the detection of occult fractures and dislocations.

MRI: Has a role in evaluating cord and ligamentous structures in various congenital and acquired pathologies.

Flexion Extension study (dynamic MRI ) helps assess fixed or unstable AAD.