From the Guidelines
The most appropriate imaging study to determine the diagnosis of scoliosis is a standing full-spine X-ray, specifically a posterior-anterior (PA) view, as recommended by the American College of Radiology (ACR) and the Society on Scoliosis Orthopedic and Rehabilitation Treatment (SOSORT) 1. This involves taking a single X-ray image of the entire spine while the patient is in a standing position, including the cervical, thoracic, and lumbar spine, as well as the pelvis. The PA view is preferred over the anteroposterior technique to reduce breast dose, and lateral radiography is recommended on initial examination and then only as subsequently dictated by alterations in sagittal balance 1. Some key points to consider when using radiography for scoliosis diagnosis include:
- Using lower-dose radiography techniques, such as computed and digital radiography, to minimize radiation exposure 1
- Employing biplanar slot scanners, if available, to lower dosage in this setting 1
- Assessing the Risser index, a measure of the degree of iliac apophysis ossification and a marker for both skeletal maturity and potential curve progression, on spinal radiographs 1
- Limiting spine radiographs to once every 12 months for those adolescent patients at Risser stages 0 to 3 and every 18 months for patients at Risser stages 4 to 5, unless there are objective clinical changes in the appearance of the scoliosis 1 While other imaging modalities like MRI or CT scans can provide more detailed information about soft tissues or bony structures, they are usually not necessary for initial diagnosis and are typically reserved for cases where there's suspicion of underlying pathology or for surgical planning 1.
From the Research
Imaging Studies for Scoliosis Diagnosis
The most appropriate imaging study for diagnosing scoliosis is radiography, specifically postero-anterior erect full spine radiograph, which is the gold standard in the evaluation and management of scoliosis curves 2. This imaging modality enables the diagnosis and monitoring of adolescent idiopathic scoliosis (AIS) and is used to measure the Cobb angle, a key indicator of scoliosis severity.
Alternative Imaging Modalities
Other imaging modalities, such as:
- Computed Tomography (CT) and Magnetic Resonance Imaging (MRI), may be used to assess underlying pathology in patients with atypical presentations of scoliosis 2, 3.
- Surface topography, which offers a non-invasive approach to monitoring changes in curvature, but has limitations in measuring the Cobb angle, particularly when the patient is in-brace 2.
- 3D ultrasound, which has been found to accurately measure the Cobb angle, but is still in the early developmental stages and has inherent technical limitations 2, 4.
- EOS® stereoradiography, which reduces radiation hazard, but is expensive and not commonly available 2.
Key Considerations
When selecting an imaging study for scoliosis diagnosis, consider the following:
- Radiation hazard: Radiography is associated with radiation exposure, and alternative modalities like 3D ultrasound may be preferred for serial monitoring 4, 5.
- Accuracy: Radiography is the gold standard for measuring the Cobb angle, but other modalities like 3D ultrasound may also be accurate 4.
- Availability: EOS® stereoradiography and 3D ultrasound may not be widely available, limiting their use in clinical practice 2, 4.
Recent Advances
Recent studies have explored the use of computerized-assisted scoliosis diagnosis based on Faster R-CNN and ResNet for the classification of spine X-ray images, which has strong potential in clinical utility applied to the field of orthopedics 6.