What are the imaging modalities for diagnosing Scoliosis (scoliosis)?

From the Guidelines

Imaging for scoliosis should typically begin with standing full-spine radiographs, including posteroanterior (PA) and lateral views, as they are necessary for initial diagnosis and monitoring of curve severity 1. The primary goal of imaging in scoliosis is to assess the severity of the curve, monitor its progression, and evaluate the risk of curve progression.

Key Considerations

• For initial diagnosis, only plain radiographs are necessary, which allow measurement of the Cobb angle to quantify curve severity 1.
• Follow-up imaging frequency depends on curve severity and skeletal maturity, with adolescents typically needing X-rays every 4-6 months during growth spurts and adults with stable curves requiring less frequent monitoring 1.
• MRI is indicated when neurological symptoms are present, curves are atypical (left thoracic curves), progression is rapid, or when congenital abnormalities are suspected, as it can help identify underlying neural axis abnormalities 1.
• CT scans are generally reserved for pre-surgical planning to evaluate complex vertebral anomalies, while EOS imaging, which uses significantly lower radiation doses, is becoming increasingly available and preferred for monitoring, especially in children requiring frequent imaging 1.

Radiation Exposure Minimization

• Radiation exposure should be minimized by limiting the frequency of conventional X-rays, using PA rather than AP views when possible, and employing gonadal shielding appropriately 1.

Special Considerations

• Congenital scoliosis, resulting from a failure of vertebral formation or segmentation, accounts for up to 10% of surgical patients with scoliosis, and MRI is suggested for the complete evaluation of congenital scoliosis to identify underlying intraspinal anomalies 1.
• The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions, including scoliosis, and provide recommendations for imaging and treatment procedures 1.

From the Research

Scoliosis Imaging Modalities

• Radiography is the primary imaging modality used in the diagnosis and monitoring of scoliosis 2
• Computed Tomography (CT) and Magnetic Resonance (MR) imaging are used when an underlying osseous or neurologic cause is suspected 2
• EOS imaging system has been shown to have the lowest radiation dose compared to CT and projection radiography 3

Imaging Features and Measurements

• The Cobb method is used to measure the degree of angulation in scoliosis 2
• The Nash-Moe method is used to measure the degree of vertebral rotation 2
• The Lenke system is used to classify the longitudinal extent of spinal involvement 2

Radiation Risk and Safety

• Scoliotic patients are frequently exposed to radiation, making it essential to minimize radiation risk 3, 4
• CT Scan Projection Radiograph (SPR) mode has been shown to deliver lower radiation doses than projection radiography in some protocols 3
• The use of dosimetry phantoms and thermoluminescent dosimetry detectors can help measure organ dose values and reduce radiation risk 3

Diagnostic Evaluation and Treatment

• Plain radiographs and MR imaging are commonly used in the diagnostic evaluation of scoliosis 4
• The treatment of idiopathic scoliosis is governed by the severity of the initial curvature and the probability of progression 2
• Treatment options include anti-inflammatory drugs, body braces, and corrective surgical procedures 5