Fig. 1From: How to improve the safety of bicortical pedicle screw insertion in the thoracolumbar vertebrae: analysis base on three-dimensional CT reconstruction of patients in the prone positionSchematic showing the measured parameters: AVD = the relative distance between the Aorta and vertebral body: VVD = the relative distance between the Inferior Vena Cava and vertebral body; ∠1 = ∠AOY: The relative angle between aorta and vertebral body; ∠2 = ∠VOY: The relative angle between IVC and vertebral bodyBack to article page