Spine X-Ray (Cervical)

Cervical spine radiographs assess vertebral alignment, bony integrity, disc spaces and prevertebral soft tissues. In acute trauma, CT has replaced plain films as the primary test in most guidelines because of its superior sensitivity, but radiographs still have a role in low-risk trauma, degenerative neck pain, and dynamic assessment of instability. A technically adequate series must visualise C1 to the C7-T1 junction to be diagnostically valid.

Indications

Neck trauma in low-risk patients per validated clinical decision rules
Chronic mechanical neck pain and suspected degenerative disease
Assessment of cervical alignment and suspected instability (flexion/extension views)
Suspected inflammatory arthropathy (rheumatoid, ankylosing spondylitis) affecting the atlantoaxial joint
Evaluation of congenital anomalies and postoperative alignment/hardware
Radicular symptoms with suspected foraminal narrowing (oblique views)
Screening for gross bony metastasis or lesion

Contraindications & Cautions

In significant trauma, do not perform flexion/extension views acutely - CT (and MRI for cord/ligament) is preferred
Immobilisation must be maintained until injury is excluded in high-risk trauma
Pregnancy: neck shielding and justification; dose to the fetus is negligible but justify
Low radiation dose (~0.06 mSv) but apply ALARA, especially the radiosensitive thyroid
Apply NEXUS or Canadian C-spine rules to avoid unnecessary imaging

Patient Preparation

Remove necklaces, earrings, dentures and hairpins from the field
Maintain spinal precautions and collar until instability is excluded in trauma
For the swimmer's or lateral view, position shoulders down (traction) to visualise the cervicothoracic junction
Explain the open-mouth (odontoid) view and coach the patient to hold still
Flexion/extension views only when the patient is alert, cooperative, neurologically intact and can move actively within pain limits
Confirm pregnancy status where relevant

Technique & Parameters

Standard three-view series: AP, lateral and open-mouth (peg/odontoid) views
The lateral view must include the base of skull to the C7-T1 junction; use a swimmer's view if the cervicothoracic junction is obscured
Open-mouth AP demonstrates the odontoid peg and lateral masses of C1-C2
70-80 kVp with fine detail; short exposure to reduce motion
Oblique views (45 degrees) demonstrate the neural foramina and pedicles when foraminal stenosis is suspected
Flexion and extension lateral views assess dynamic instability when clinically appropriate
Ensure the whole cervical spine is captured before clearing the spine radiographically

Systematic Review

Adequacy: confirm C1 to C7-T1 is visualised on the lateral view
Alignment (ABCs): trace anterior vertebral line, posterior vertebral line, spinolaminar line and spinous process tips - all should form smooth curves
Bones: vertebral body height, cortical outline, pedicles, laminae, spinous processes and the odontoid
Cartilage/joints: intervertebral disc space heights and facet joint congruity
Soft tissues: prevertebral space (<7 mm at C2-C3, <22 mm or one vertebral body width at C6)
Assess the atlanto-dens interval (<3 mm adult, <5 mm child) and predental space
On the open-mouth view check symmetry of C1 lateral masses over C2
Count vertebrae and verify no step-off or fanning of spinous processes

Key Findings & Significance

Loss of alignment or step-off of the vertebral lines suggests subluxation or fracture-dislocation
Increased prevertebral soft-tissue swelling indicates haematoma from an underlying injury
Widened atlanto-dens interval indicates transverse ligament disruption or atlantoaxial instability
Fanning (widening) of interspinous distance suggests posterior ligamentous injury
Loss of disc height, osteophytes and facet arthropathy indicate cervical spondylosis
Anterior wedge compression or teardrop fragment indicates a flexion injury
Odontoid lucency indicates a dens fracture (types I-III)
Foraminal narrowing on obliques from uncovertebral or facet osteophytes correlates with radiculopathy

Differential Considerations

Vertebral malalignment: traumatic subluxation, degenerative spondylolisthesis, ligamentous laxity, pseudosubluxation in children
Odontoid lucency: fracture, os odontoideum, mach effect artefact, prior non-union
Prevertebral widening: haematoma, abscess (retropharyngeal), tumour, normal in expiration/children
Reduced disc height with osteophytes: spondylosis, prior discitis, DISH
Erosive/destructive change: metastasis, myeloma, infection, rheumatoid pannus
Fused vertebrae: congenital (Klippel-Feil), ankylosing spondylitis, prior surgery or juvenile arthritis
Widened atlanto-dens interval: rheumatoid arthritis, Down syndrome, trauma

Pearls & Pitfalls

An inadequate series that fails to show C7-T1 is a common cause of missed injuries; obtain a swimmer's view or CT
Pseudosubluxation of C2 on C3 (and C3 on C4) is normal in children up to ~8 years; use the posterior cervical line of Swischuk
Up to 20% of cervical injuries have a second, non-contiguous spinal injury - image the whole spine if one fracture is found
Prevertebral soft-tissue swelling may be the only clue to a subtle fracture
Plain films miss a significant proportion of fractures; CT is the standard in moderate/high-risk trauma
The Mach effect and overlapping teeth/occiput can mimic an odontoid fracture on the open-mouth view
Flexion/extension views obtained with muscle spasm can be falsely reassuring; repeat when spasm settles

Structured Report

State views obtained and adequacy (including whether C7-T1 was seen)
Report alignment of the four lines, vertebral body and posterior element integrity
Describe disc spaces, facet joints and prevertebral soft tissues with measurements (ADI, prevertebral space)
State degenerative versus traumatic versus destructive nature of any abnormality
Impression: presence or absence of fracture/instability and any recommendation for CT or MRI
Recommend MRI when cord compression, ligamentous injury or neurological deficit is suspected

References

Hoffman JR et al. NEXUS Low-Risk Criteria; Stiell IG et al. Canadian C-Spine Rule
ACR Appropriateness Criteria: Suspected Spine Trauma
Royal College of Radiologists iRefer guidelines
Raby N, Berman L, de Lacey G. Accident and Emergency Radiology: A Survival Guide, Elsevier
ACR-ASNR-SCBT-MR Practice Parameter for the Performance of Cervical Spine Imaging

Educational clinical decision support only. Protocols vary by institution and equipment; always confirm with a qualified radiologist and local guidelines before clinical use.

Spine X-Ray (Cervical)

📋 Indications

⛔ Contraindications & Cautions

🧑‍⚕️ Patient Preparation

⚙️ Technique & Parameters

🔎 Systematic Review

🩻 Key Findings & Significance

🧠 Differential Considerations

💡 Pearls & Pitfalls

📝 Structured Report

📚 References