Cervical spine (flexion-extension views)

Dr Henry Knipe and Andrew Murphy et al.

Cervical spine flexion-extension lateral views are specialized projections of the cervical spine often requested to assess for spinal stability.

Cervical spine flexion-extension lateral views should not be performed on trauma patients without strict instructions of a qualified clinician.

  • the patient is erect, left side against the upright detector 
  • the detector is placed portrait, parallel to the long axis of the cervical spine on the patients left the side 
  • the patient will have the neck in the extended (chin up) or flexion (chin down) position depending on the projection
  • lateral projection
  • centering point
    • 2.5 cm above the jugular notch at the level of T1
  • collimation
    • superior to C1
    • inferior to T1
    • anterior to include soft tissue
    • posterior to the soft tissue
  • orientation  
    • portrait 
  • detector size
    • 24 cm x 30 cm
  • exposure
    • 50-75 kVp
    • 20-50 mAs
  • SID
    • 150-180 cm
  • grid
    • yes
  • there should be a clear visualization of C7 to T1
  • the image is labeled as 'flexion' or 'extension'  
  • flexion images should demonstrate well separated spinous process 
  • extension images should demonstrate crowding of the spinous process
  • demonstrate to the patient what flexion and extension is before performing 
  • ensure the patient is aware when the examination is over as to avoid extended periods of time in that position 
  • patients whom feel unstable on their feet and can sit in a chair for this examination 
  • ensure this radiographic series is safe to perform, i.e. part of a secondary survey or under the guidance of an authorized physician 
Radiographic views
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Article information

rID: 58732
Section: Radiography
Tag: refs, cases
Synonyms or Alternate Spellings:

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Cases and figures

  • Os odontoideum (f...
    Figure 1: flexion view
    Drag here to reorder.
  • Os odontoideum (e...
    Figure 2: extension view
    Drag here to reorder.
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