Spine Radiography (X-ray)¶

Definition¶

Spine radiography (plain film X-ray) is the most basic and widely available imaging modality for evaluating the vertebral column. It uses ionizing radiation to produce projection images of bony structures and is typically the first-line study for assessing spinal alignment, fractures, degenerative changes, and overall bony anatomy.

Technique¶

Standard Views¶

Region-Specific Protocols¶

• Cervical: AP, lateral, open-mouth odontoid; obliques and swimmer's view as needed
• Thoracic: AP and lateral
• Lumbar: AP and lateral; obliques for pars evaluation; flexion/extension for instability
• Sacrum/Coccyx: AP and lateral with angled beam

Technical Considerations¶

• Patient positioning (standing vs. supine) affects alignment measurements — standing films are preferred for scoliosis and sagittal balance assessment
• Adequate penetration is essential — the cervicothoracic junction is often poorly visualized
• Gonadal shielding should be used when possible
• Digital radiography has largely replaced film-screen, improving dynamic range and post-processing capability

Indications¶

• Trauma: initial screening for fractures, dislocations, and malalignment
• Degenerative disease: disc space narrowing, osteophytes, spondylolisthesis, facet arthropathy
• Deformity: scoliosis screening and monitoring (standing full-length films)
• Post-surgical: hardware positioning, fusion assessment
• Systemic disease: vertebral compression fractures (osteoporosis), DISH, ankylosing spondylitis

Systematic Approach to Interpretation¶

Lateral View — The Three Lines¶

On the lateral radiograph, three smooth contour lines should be assessed:

1. Anterior vertebral body line — connects the anterior margins of the vertebral bodies
2. Posterior vertebral body line — connects the posterior margins of the vertebral bodies
3. Spinolaminar line — connects the junction of the laminae and spinous processes

Disruption of any of these lines suggests fracture, dislocation, or malalignment.

AP View — Key Checkpoints¶

• Spinous process alignment (deviation suggests rotational injury)
• Interpedicular distance (widening suggests burst fracture)
• Vertebral body height and width symmetry
• Disc space heights
• Paraspinal soft tissue widening (suggests hemorrhage or abscess)

Limitations¶

• Poor soft tissue contrast — cannot evaluate discs, ligaments, spinal cord, or nerve roots
• Superimposition of structures — especially problematic in the thoracic spine and cervicothoracic junction
• Limited sensitivity for non-displaced fractures, early metastatic disease, and infection
• Radiation exposure — a concern with repeated studies, particularly in young patients and scoliosis monitoring
• Largely replaced by CT for acute trauma evaluation in many centers

Key Points¶

• Spine radiography is the first-line imaging study for spinal evaluation
• The lateral view with three contour lines is the most important view for alignment assessment
• Standing films are essential for accurate scoliosis and sagittal balance measurement
• The cervicothoracic junction must be adequately visualized on lateral films
• CT has largely replaced radiography for acute trauma, but plain films remain valuable for screening, follow-up, and deformity assessment

References¶

1. Skalski MR, Matcuk GR Jr, Gibbs WN. The Art of Interpreting Cervical Spine Radiographs. RadioGraphics. 2019;39(3):820-821. doi:10.1148/rg.2019180148. Available from: https://pubmed.ncbi.nlm.nih.gov/31059402/
2. Perry JR, Stern EJ, Mann FA, Baxter AB. Lateral radiography of the cervical spine in the trauma patient: looking beyond the spine. AJR Am J Roentgenol. 2001;176(2):381-386. doi:10.2214/ajr.176.2.1760381. Available from: https://pubmed.ncbi.nlm.nih.gov/11159078/
3. Malfair D, Flemming AK, Dvorak MF, Munk PL, Vertinsky AT, Heran MK, Graeb DA. Radiographic evaluation of scoliosis: review. AJR Am J Roentgenol. 2010;194(3 Suppl):S8-S22. doi:10.2214/AJR.07.7145. Available from: https://pubmed.ncbi.nlm.nih.gov/20173177/
4. Expert Panel on Neurological Imaging; Hassankhani A, et al. ACR Appropriateness Criteria® Acute Spinal Trauma: 2024 Update. J Am Coll Radiol. 2025;22(5S):S48-S66. doi:10.1016/j.jacr.2025.02.013. Available from: https://pubmed.ncbi.nlm.nih.gov/40409895/
5. Ruiz Santiago F, Láinez Ramos-Bossini AJ, Wáng YXJ, López Zúñiga D. The role of radiography in the study of spinal disorders. Quant Imaging Med Surg. 2020;10(12):2322-2355. doi:10.21037/qims-20-1014. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC7596402/
6. Spine radiography. Radiopaedia.org. Available from: https://radiopaedia.org/articles/spine-radiography-paediatric

Related Articles¶

• Flexion-Extension Radiographs
• CT of the Spine
• MRI of the Spine
• Normal Spinal Curvatures and Alignment
• Vertebral Column Overview