Figure 3.

Measurements obtained from the centreline-based analysis: the centreline (red) is subdivided into several vertices, connected by edges. For each vertex the vessel diameter is available. The vertices P₂ and P₄ are used for the measurement of the length L, the curvature index (CI) in the RPA using the lengths L and L₀, and the RPA taper using the diameters D₂ and D₄. L₀ is the direct distance (black line with arrows) between vertices P₂ and P₄, whereas L is the length of the curved centreline (red line) connecting the same vertices. The vertex P_b marks the LPA-RPA bifurcation node. The marked vertices P₁, P₂ and P₃ are located at the distance of 10 mm from the bifurcation vertex. Diameters measured at these vertices are used to measure the enlargement index EnI. The bifurcation angle α between LPA and RPA is the angle between the vectors (black lines) connecting the P_b with P₂ and P₃.