Figure 3.

Analysis of topological characteristics. (A) Correlation between upwards complexity and bronchial tree length (Pearson correlation coefficient ρ = 0.97, p-value ρ = 1.56.10⁻⁴¹). Similar results were obtained using directional complexity in other directions. (B) Correlation between the inspiratory branch-to-branch proximity, which quantifies how branches of the inspiratory bronchial tree bend towards one another, and FEV1 (% of predicted) (ρ = 0.38, ρ = 0.040). (C) Expiratory counterpart of (b) (ρ = 0.57, ρ = 0.001). Notice that the correlation is stronger and more significant for expiratory scans than for inspiratory scans.