X Ray Cervical Spine AP View

A cervical spine AP is an anteroposterior X‑ray projection of the neck where the X‑ray beam passes from the front (anterior) to the back (posterior). It visualizes vertebral bodies, alignment, disc spaces and can detect fractures, deformity, or degenerative change. It’s commonly performed as part of a cervical spine series (with lateral and odontoid/open‑mouth views) with the patient upright or supine.

The lateral view is the single most important cervical spine X‑ray projection. It best shows vertebral alignment, intervertebral disc spaces, facet joints, prevertebral soft tissues and most fractures from occiput to C7. An AP view and an open‑mouth (odontoid) view are complementary to assess C1–C2 and frontal alignment; flexion–extension views evaluate instability when clinically indicated.

For an AP (axial) cervical spine X‑ray, the X‑ray tube is typically angled cephalad about 15–20° with the central ray directed to C4 (around the lower border of the thyroid cartilage). This angulation helps project the cervical vertebrae above the shoulders and open the intervertebral disc spaces. The open‑mouth (odontoid) view is taken with the beam perpendicular.

C1–C6 are the first six cervical vertebrae/nerve levels. C1 (atlas) supports the skull and allows nodding; C2 (axis) has the odontoid (dens) permitting head rotation. C3–C6 are typical cervical vertebrae with transverse foramina for vertebral arteries, protecting the spinal cord and giving rise to nerve roots. C3–C5 help form the phrenic nerve (diaphragm); C5–C6 power shoulder and elbow movements.

Symptoms of a cervical spine problem include neck pain or stiffness, reduced range of motion, and muscle spasm. Nerve compression can cause radiating pain, numbness, tingling or weakness in the shoulders, arms or hands. Headaches (especially at the base of the skull), balance problems, difficulty with coordination or fine motor tasks may indicate spinal cord involvement. Severe cases can cause gait disturbance and bowel or bladder dysfunction.

The normal anteroposterior (AP) diameter of the cervical spinal canal is about 17–18 mm. An AP diameter under roughly 13 mm is generally considered narrowed (cervical stenosis), and measurements around 10–12 mm indicate more severe stenosis with greater risk of spinal cord compression. Interpret values alongside imaging modality and clinical findings.