Facial bones (reverse Waters)

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The acanthioparietal or reverse water's view modified Water's view used in trauma. It can be used to assess for facial fractures, as well as for acute sinusitis. Skull radiographs, in general, are rapidly becoming obsolete, being replaced by much more sensitive CT scans.

Patient position

  • the patient is supine
  • the mid-sagittal plane is perpendicular to the image receptor 

Technical factors

  • acanthioparietal projection
  • centering point
    • acanthion
    • central beam angled 30 degrees cephalad to be running parallel to the mentomeatal line
  • collimation
    • superior to the skin margins
    • inferior to include the most inferior aspects of the skull
    • lateral to include the skin margin
  • orientation  
    • portrait
  • detector size
    • 24 cm x 30 cm
  • exposure
    • 75-80 kVp
    • 20-25 mAs
  • SID
    • 100 cm
  • grid
    • yes (this can vary departmentally)

Image technical evaluation

  • orbits are magnified 
  • petrous ridges are projected below the maxillary sinus 

Practical points

  • learn your skull positioning lines, it makes for reading position guides a lot easier
  • this projection should only be used on patients unable to stand up, anatomy is distorted on this projection