see also:

• radiology
• CT brain
• cervical spine injury
• thoracic spine trauma
• lumbar spine trauma
• the lumbosacral spine Xray
• trauma

• 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

• “CT attenuation measurements can be used to distinguish untreated osteoblastic metastases from enostoses. A mean attenuation of 885 HU and a maximum attenuation of 1060 HU provide reliable thresholds below which a metastatic lesion is the favored diagnosis.” ie. HU levels higher than these cutoffs strongly suggest enostosis rather than met with ~95% sens and 96% specificity in the study. ¹⁾
• other suggestive features of enostoses:
  • The appearance of radiating spicules - “thorny radiation” or “fingers” - at the margins that blend with the surrounding trabeculae is classic, giving a “brush-like” or “stellate” periphery.
  • Absence of periosteal reaction or cortical destruction