AP Axial Cervical is a radiography positioning projection of the Spine. Supine, CR 15-20° cephalad, centered C4. Lower cervical survey. The centering point is located c4 vertebra, at level of lower neck.. The central ray is 15-20 degrees cephalad to ir.. Image-quality criteria include c3-c7 vertebrae clearly visualized., intervertebral disc spaces open and symmetrical.. Standard exposure ranges from 75 to 85 kVp, 8 to 15 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- C3-C7 vertebral bodies.
- Intervertebral disc spaces C3-C7.
- Spinous processes of lower cervical vertebrae.
- Lateral cervical processes.
- Lower cervical lordotic curve.
Patient preparation
- Verify patient identity using two identifiers.
- Remove neck jewelry, dentures, and radiopaque objects.
- Supine on table with no head rotation or tilt.
- Head in neutral alignment.
- Shoulders relaxed away from neck.
Position & centering point
C4 vertebra, at level of lower neck.
Central ray
15-20 degrees cephalad to IR.
Exposure / technique
- kVp
- 75–85
- mAs
- 8–15
- SID
- 40" (102 cm)
- Notes
- Cephalad angle opens intervertebral disc spaces.
Image-quality criteria
- C3-C7 vertebrae clearly visualized.
- Intervertebral disc spaces open and symmetrical.
- Spinous processes visible midline.
- No rotation evidenced by symmetric lateral processes.
- Entire lower cervical region included on radiograph.
Common errors / ARRT traps
- 1 Insufficient cephalad angle closes disc spaces.
- 2 Excessive cephalad angle obscures lower vertebrae.
- 3 Head rotation shifts lateral masses off symmetry.
- 4 CR not centered to C4 misses pathology.
Clinical indications
- Lower cervical spine trauma survey.
- Suspected fracture of C3-C7 vertebrae.
- Evaluation of disc space narrowing.
- Assessment of vertebral alignment in flexion.
Aligned to the 2025 ARRT Content Specifications.