Computed tomography-derived assessment of respiratory impairment in thoracic scoliosis: Comparison between idiopathic and non-idiopathic etiologies

Figure 1 Spinal thoracic deformity parameters. A: The Cobb angle was measured as the angle between the upper endplate of the most tilted superior vertebra and the lower endplate of the most tilted inferior vertebra of the thoracic curve. Apical vertebral translation was defined as the horizontal distance between the center of the apical vertebra and a plumb line drawn through C7 on the anteroposterior view of spinal computed tomography; B: The apical vertebral body-rib ratio was defined as the ratio of the right-sided distance to the left-sided distance from the edge of the vertebral body to the ribs. Apical vertebral rotation was defined as the rotation of the vertebral body axis relative to the anterior midline and the plumb line. AVT: Apical vertebral translation; AVB-R: Apical vertebral body-rib ratio; RAml: Rotation relative to anterior midline; RAsag: Rotation relative to sagittal plane.