Scoliosis (PA/AP view)

Last revised by Andrew Murphy on 19 Sep 2021

The scoliosis posteroanterior/anteroposterior (PA/AP) view allows for the visualization of the thoracic and lumbar vertebral bodies of interest.

This projection is used in determining scoliosis in patients and allows for the severity of lateral spinal curvature to be assessed 1.


  • patient erect (or supine depending on protocol)
  • if patient erect, arms by sides and equal weight on both feet
  • ensure patient aligned centrally to the image receptor
  • ensure rotation of hips and shoulders is reduced as much as possible (some rotation inherent to scoliosis may be inevitable)
  • ensure at least 3-5 cm of iliac crests are present on radiograph
  • anteroposterior or posteroanterior projection
  • suspended expiration
  • centering point
    • dependent on area of interest, patient height and detector size
  • collimation
    • dependent on orthopedic preference and imaging modality
    • superiorly to include all vertebrae of interest (may be at C7)
    • inferiorly to include sacral region (may be at S1 or level of femoral heads)
    • lateral collimation sufficient to include all of spinal curvature
  • orientation
    • portrait
  • detector size
    • 35 cm x 43 cm
    • 35 cm x 90 cm (if available)
  • exposure
    • 80-95 kVp (digital)
    • 40-60 mAs
  • SID
    •  100 cm - 150 cm
  • grid
    • yes


  • area of scoliosis should be visible with evidence of iliac crests inferiorly
  • no patient rotation
    • rotated vertebrae may be distinguished from scoliotic vertebrae in that:
      • rotated vertebral bodies will have their long axes straight and
      • scoliotic vertebral bodies will have a lateral deviation
  • long axis of the spine should be straight along the long axis of the IR
  • bony margins and trabecular patterns should both be clearly visible in thoracic and lumbar vertebrae
  • PA projections should be considered over the AP projection for the reduced dose to radiosensitive organs situated anteriorly
  • a compensatory wedge filter may be appropriate to achieve an even density throughout the image 1




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Cases and figures

  • Case 1: levoscoliosis
    Drag here to reorder.
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