Fig. 2

CTA image analysis protocol for the ACAOS. a For stenosis severity ranking, a degree of stenosis less than 50% were classified as mild stenosis and a degree of stenosis equal or more than 50% were classified as severe stenosis. b the high-risk anatomy characteristics identification protocol, including “slit-like” vessel, Height-to-width ratio (HW ratio), angle at the take-off level, and the shared or separate ostium