CT spine - cervical (Cx), thoracic (Tx) or lumbar (Lx)

Interpretation of CT spine

basic concepts

3 Denis spinal columns concept of spinal injury
- initially was applied to thoracolumbar injuries in 1976 but is applicable to lower cervical injuries as well
- anterior column
  - anterior 2/3rds of vertebral bodies includes anterior longitudinal ligt (ALL) and anterior annulus
- middle column
  - posterior 1/3rds of vertebral bodies includes posterior longitudinal ligt (PLL) and posterior annulus
- posterior column
  - all the rest - posterior bony elements (pedicles, facets, lamina, spinous process) and posterior ligaments including ligamentum flavum
- injury to 2 contiguous columns suggests instability
- if there is an anterior fracture, look hard for a middle or posterior injury
- see also https://radiopaedia.org/articles/three-column-concept-of-spinal-fractures
systematic assessment of images
- on the lateral:
  - alignment of ALL, PLL, and ligamentum flavum
  - predental space
  - anterior soft tissue diameter 7-2 rule: 7mm at C2, 2cm at C7
  - assess the 3 columns
- look for C1 Jefferson injuries
- assess dens
- assess facet joints
blunt cerebrovascular injury
- signs and symptoms
  - arterial haemorrhage
  - cervical bruit in patient < 50 yrs age
  - expanding cervical haematoma
  - focal neurologic deficit
  - neurologic exam incongruous with CT brain findings
  - stroke on secondary CT brain
- risk factors indicating need for CT angiography
  - high energy trasfer mechanism with:
    - Le Fort fracture type 2 or 3
    - base of skull fracture involving carotid canal
    - diffuse axonal injury with GCS < 6
    - cervical spine fractures that involve C1-3 and/or, transverse foramen
    - cervical spine subluxation
    - near hanging with hypoxic ischaemic brain injury