Skull (Towne view)

Towne"s
view of a bilateral condyle fracture. White arrow is a fracture on the neck of the condyle. Black arrow shows the condyle pulled to the medial. The same injury can be seen on the opposite side
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The Towne view is an angled anteroposterior radiograph of the skull and visualizes the petrous part of the pyramids, the dorsum sellae and the posterior clinoid processes, which are visible in the shadow of the foramen magnum.

Indications

This projection is used to evaluate for medial and lateral displacements of skull fractures, in addition to neoplastic changes and Paget disease.

Patient position

  • nuchal ridge is placed against the image detector
  • the infraorbitomeatal line perpendicular to the image receptor

Technical factors

  • anteroposterior axial projection
  • centering point
  • collimation
    • superior to include skin margins
    • inferior to include base of skull
    • lateral to the skin margins 
  • orientation  
    • portrait
  • detector size
    • 24 cm x 30 cm
  • exposure
    • 60-70 kVp
    • 10-20 mAs
  • SID
    • 100 cm
  • grid
    • no

Image technical evaluation

  • dorsum sella overlies the foramen magnum
  • petrous ridges are symmetrical 

Practical points

  • if the dorsum sella projects above the foramen magnum it requires an increase in angle
  • if the anterior arch of C1 is laying in the foramen magnum, less angle is required
Advantages
  • occipital bone and posterior fossa space better evaluated than with a non angulated AP view, which would have more skull base and facial bone overlap
  • better than a conventional AP view for evaluating an occipital plagiocephaly involving the lambdoid suture 
  • may be a useful additional view for evaluating skull fractures