Cervical spine (Fuchs view)

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The closed mouth odontoid AP view (Fuchs view) is a non-angled AP radiograph of C1 (atlas) and C2 (axis).

Indications

This view focuses primarily on the odontoid process, and is useful in visualizing odontoid and Jefferson fractures. The standard Fuchs view (Figure 1 & 3) should not be used in a trauma setting and the modified Fuchs view (Figure 2) may be used instead.

Patient position

  • supine or erect
  • head placed against the image detector
  • chin angled up 35-40°

Technical factors

  • anteroposterior projection
  • centering point
    • the beam is aimed just underneath the chin
  • collimation
    • superior to the TMJ
    • inferior to include C2/3
    • 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

The entire odontoid process should be visibly to avoid obscuring anatomy.

Practical points

More likely to avoid structures overlapping the odontoid than with the open mouth odontoid view.

This view should not be used in a trauma setting (to avoid manipulating a potentially unstable spine) the modified Fuchs view may be used instead; instead of moving the patient's chin, the beam is angled 35-40° upward and the odontoid is targeted just under the chin (the chin is in a neutral position).