Fig. 1

(A) Volume-rendered CT images of the pulmonary arteries showing the pulmonary artery bending angle (red asterisk) as the outer angle between main pulmonary artery axis (axis 1) and branch pulmonary artery axis (axis 2), (B) Axial oblique CT image showing the cross-sectional area of the pulmonary artery (yellow circle). PA: main pulmonary artery