Recommended X-ray Views for Diagnosing and Monitoring Scoliosis
For diagnosing and monitoring scoliosis, posteroanterior (PA) and lateral radiographs of the complete spine are the primary recommended imaging views, with PA views being essential for regular follow-up monitoring. 1
Initial Diagnosis: Required Views
Posteroanterior (PA) view:
- Preferred over anteroposterior (AP) to reduce breast radiation exposure
- Allows visualization of lateral curvature and measurement of Cobb angle
- Permits assessment of vertebral rotation using Nash-Moe method
- Enables identification of congenital vertebral anomalies
- Allows assessment of Risser index (iliac apophysis ossification) for skeletal maturity
Lateral view:
- Required at initial examination
- Evaluates sagittal balance and kyphosis/lordosis
- Helps distinguish between structural and non-structural curves
- Subsequent lateral views only needed if changes in sagittal balance are suspected
Monitoring Protocol
The frequency of radiographic monitoring should follow these guidelines 1:
- Congenital scoliosis: No more than once every 6 months
- Adolescent idiopathic scoliosis:
- Risser stages 0-3 (skeletally immature): Once every 12 months
- Risser stages 4-5 (approaching skeletal maturity): Once every 18 months
- More frequent imaging only if objective clinical changes are observed
Special Radiographic Views for Surgical Planning
For patients requiring surgical intervention, additional views may be necessary 1, 2:
- Side bending views: Assess curve flexibility
- Push prone views: Evaluate curve reducibility
- Fulcrum bending views: Determine structural nature of curves
- Traction views: Assess potential for surgical correction
- Supine views: Can predict non-structural minor curves
Radiation Reduction Techniques
To minimize radiation exposure, especially important in pediatric patients requiring serial imaging 1:
- Use digital or computed radiography instead of conventional film
- Consider biplanar slot scanners if available
- Employ lower-dose radiography techniques
- Use PA views instead of AP views to reduce breast radiation dose
When Additional Imaging Modalities Are Warranted
While X-rays remain the primary imaging modality, certain clinical scenarios warrant additional imaging:
MRI indicated when:
- Congenital scoliosis is present (43% have intraspinal anomalies)
- Rapid curve progression (>1° per month)
- Left thoracic curve (atypical curve pattern)
- Short segment curve (4-6 levels)
- Absence of apical segment lordosis
- Functionally disruptive pain
- Focal neurologic findings
- Male sex with significant curve
CT indicated for:
- Presurgical planning
- Visualization of complex bony malformations
- Surgical navigation to optimize screw placement
Common Pitfalls to Avoid
- Overuse of radiation: Adhere to recommended frequency guidelines
- Missing the apex vertebra: Critical for proper Cobb angle measurement
- Incorrect positioning: Patient must be properly positioned for accurate measurements
- Neglecting sagittal plane: Scoliosis is a three-dimensional deformity
- Overlooking skeletal maturity: Risser index on radiographs provides crucial information about growth potential and risk of progression
By following these evidence-based recommendations for radiographic imaging, clinicians can effectively diagnose and monitor scoliosis while minimizing radiation exposure and optimizing patient outcomes.