Pediatric cervical spine (odontoid view)

The odontoid cervical spine view for pediatrics is an anteroposterior projection for assessing C1 (atlas) and C2 (axis) vertebrae.

Indications

This view will only performed when C1 and C2 need to be assessed for trauma or in the setting of a chiropractic series in pediatrics.

Patient position

• the patient is erect with the posterior aspect of the cervical spine in contact with the upright detector

• both shoulders in contact with the detector to avoid rotation

• at the last instant, the patient is instructed to open their mouth as wide as possible 

• the head should be positioned so the lower margin of the upper incisors and the base of the skull are perpendicular to the image receptor

Technical factors

• anterior-posterior projection

• centering point

  • at the center of the open mouth

• collimation

  • laterally to include the mandible

  • superiorly to include the upper incisors

  • inferiorly to include the lower incisors

• orientation

  • landscape

• detector size

  • 18 cm x 24 cm

• exposure ¹

  • 65-70 kVp

  • 2-5 mAs

• SID

  • 100 cm

• grid

  • no

Image technical evaluation

Symmetry is seen between C1 and C2 zygapophyseal joint spaces. The dens axis should also be free of superimpositions of the adjacent atlas lateral masses and clearly visualized ². A physical metal marker is ideal for pediatric imaging. 

Practical points

Preparing the room beforehand (setting up the detector, exposure and preparing lead gowns) is important as pediatric patients may not remain still.

Immobilization techniques

The radiograph must be free from motion artifacts and rotation to avoid repeated x-rays.

• it may be necessary for the parent or radiographer to hold the patient in position

• ideally, the parent should be in the child's direct line of sight

• techniques will vary based on the department

• distraction techniques can be utilized to avoid scattered radiation to parents and staff ³