Lumbar spine (oblique view)

The lumbar spine oblique view is used to visualise the articular facets and pars interarticularis of the lumbar spine. 

  • the radiographs can be performed with the patient in the erect or supine position
    • erect
      •  two radiographs performed with patient at RAO 35-45°  and LAO 35-45°  
    • supine
      •  two radiographs performed with patient at RPO 35-45°  and LPO 35-45°  
  • ensure arms are removed from the region of interest 
  • using a 45° radiolucent sponge in the supine position will assist the patient in maintaining the correct position, whilst flexing the knees will also provide stability. 
  • left and right oblique positions
  • expiration (to minimise superimposition of the diaphragm over the upper lumbar spine) 
  • centring point
    • PA erect- 2.5cm above the iliac crests and 3cms lateral from the spinous processes towards the upside. RAO and LAO will demonstrate the facet joints on the upside, for example, the LAO position will show the right facet joint
    • AP supine- 2.5cms above the iliac crests and 5cms medial from the ASIS on the upside. RPO and LPO will demonstrate the facets joints on the downside, for example for RPO will show the right facet joint 
  • collimation
    • superiorly to include the T12/L1 junction 
    • inferior to include the L5/S1 junction 
    • anterior to include the anterior border of the lumbar vertebral bodies 
    • posterior to include all elements of the posterior column, particularly the spinous processes 
  • orientation  
    • portrait
  • detector size
    • 35 cm x 43 cm 
  • exposure
    • 70-80 kVp
    • 60-80 mAs 
  • SID
    • 110 cm
  • grid
    • yes (ensure the correct grid is selected if using focused grids)
  • the entire lumbar spine should be visible from T12/ L1- L5/S1
    • check department protocol before imaging, as focused imaging of the lower lumbar vertebrae may be required 
  • a well positioned oblique lumbar radiograph will demonstrate the scottie dog sign, showing the articular processes and facet joints  
  • adequate image penetration and image contrast is evident by clear visualisation of lumbar vertebral bodies, with both trabecular and cortical bone demonstrated
  • pedicles should be in the central of the vertebral bodies 
  • to correct poor positioning consider the location of the pedicles
    • if they are anterior on the vertebral body- rotate the patient more
    • if they are posterior on the vertebral body- rotate the patient less
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Article Information

rID: 49730
Section: Radiography
Tag: snippet
Synonyms or Alternate Spellings:

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Cases and Figures

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    Figure 1: Scotty dog appearance: oblique view
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    Case 1: Scotty dog appearance on facet joint injection
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