How to interpret a lateral cervical spine X ray
- • Count the vertebral bodies. All seven cervical vertebral bodies and C7-T1 should be visualized.
- • Evaluate for presence of fractures.
- • Evaluate the thickness of prevertebral soft tissue. It should be less than 6-7 mm anterior to C2-C3, and its thickness should be less than 18-21 mm anterior to C6-C7. When the prevertebral soft tissue appears thickened on a lateral radiograph in the setting of acute trauma, this is suggestive of presence of prevertebral edema and/or hemorrhage related to underlying osseous or soft tissue injury.
- • Assess four parallel lines for alignment. From anterior to posterior, these are the anterior vertebral, posterior vertebral, spinolaminar, and posterior spinous lines
- • Examine the atlantoaxial interval, which is the distance between the posterior margin of the anterior arch of C1 (atlas) and the anterior margin of the odontoid process of C2 (axis). This space should not exceed 3 mm in adults and 5 mm in children. This interval should remain constant with flexion and extension in adults. Widening of this space indicates disruption of the transverse ligament of the atlas.
- • Compare the intervertebral disc spaces for widening or narrowing.
