On which radiographic view is the Cobb angle measured for scoliosis assessment?

• A. Standing AP radiograph.
• B. Lateral radiograph.
• C. Standing PA radiograph.
• D. Supine AP radiograph.

Answer: (A)

The main idea is that the Cobb angle is determined from a frontal view of the entire spine while the patient is standing. This posture shows the curve under normal gravitational loading, giving a true representation of scoliosis severity and allowing consistent comparison over time. A lateral view only shows the sagittal (side) profile, not the coronal curvature used for the Cobb angle. A supine radiograph removes weight-bearing effects, often reducing the apparent curve and underestimating the deformity. When measuring, you identify the uppermost and lowermost vertebrae involved in the curve, draw lines along their endplates, and measure the angle between those lines to quantify scoliosis.