Scoliosis (PA/AP view)

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 .

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