Timely Tip

TimelyTip

The Odontoid Process

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Has this ever happened to you? It's late at night and you’re covering the department alone. Requests for portables are starting to pile up; the phone is ringing, surgery is calling and the ER rolls in a Stat patient for a better view of the odontoid taken earlier. (once again...left overs from the previous shift)

Or, it’s another busy day in the clinic and the requests are stacking up. One of the doctors must desperately must see a satisfactory odontoid view to 'clear' his patient.

For most of us mere mortals, satisfactorily radiographing the the AP atlas & axis, is no small task. If the frontal teeth don’t get in the way, the base of the skull does. The patient may be a trauma victim or, god love them, 86 years old with severe lordosis of the C-Spine and severe kyphosis of the T-Spine

Tip

Technique

1. Place the patient in an AP position in relationship to the radiation source.
2. Direct the CR centrally to an imaginary line between the lower margin of the anterior upper teeth to the tip of the mastoid process. <When possible, this line should be perpendicular to the film.>

It may not always be possible to direct the CR perpendicular⁽¹⁾. Regardless of the up/down tilt of the patients head, get the patients mouth open as wide as possible and angle the tube to direct the CR parallel to the lower margin of the imaginary line created by the upper teeth (incisor along the molars). This will correspond to a line from the front teeth to the mastoid process.

Sometimes the tube angle may make it seem you’re over compensating the CR. Providing you keep the CR parallel with the line created by the lower margin of the upper teeth, viola perfect odontoid films every time.

⁽¹⁾If the patient is sitting, change perpendicular to horizonal.