Assessment of biomechanical properties in pulmonary arterial hypertension: a computational fluid dynamics study of the extensive pulmonary arterial tree

Figures

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  Fig. 1. Geometry of the pulmonary artery tree from a representative PAH subject (Case P3) with inlet and outlet regions. The inlet and outlet extensions (5 × hydraulic diameter, Dh) were standardized across all subjects to ensure consistent boundary conditions

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  Fig. 2. Comparison of hemodynamic parameters across the cohort (n = 7 PAH subjects). a Area-averaged velocity at the inlet over a cardiac cycle. b Velocity distribution at inlet, main body, and outlet. c Cross-sectional area reduction at the outlet compared to the inlet (P < 0.0001). Data are presented as mean ± SD. Note: Asteriks denote statistical significance, with * P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001

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  Fig. 3. Temporal variation of Wall Shear Stress (WSS) in a healthy control (a) and a representative PAH subject (Case P3, b) at five cardiac phases (t1–t5). The PAH subject exhibits consistently lower WSS in the proximal artery compared to the distal segments

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  Fig. 4. Time-averaged WSS (TAWSS) distribution in the pulmonary artery tree of a representative PAH subject (Case P7). a, d TAWSS across the extensive pulmonary artery tree (up to 6 th-generation branches), main, and branches in PAH subject. b Anterior views of proximal arteries. c TAWSS at inlet vs. outlet. d Comparison of TAWSS in main vs. branch segments. Note: Asteriks denote statistical significance, with * P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001

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  Fig. 5. Streamline visualization of blood flow in the same PAH subject (Case P5) during peak systole (a) and early diastole (b). Helical flow patterns (arrows) are more pronounced during diastole, particularly in the dilated proximal arteries. The color map represents flow velocity in [cm/s], with higher velocities indicated by warmer colors and lower velocities by cooler colors. The arrows highlight regions of interest with notable flow patterns

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  Fig. 6. Oscillatory Shear Index (OSI) in the representative PAH subject (Case P5). a-b Anterior/posterior views of the entire arterial tree, highlighting disturbed flow regions (color scale up to OSI = 0.4). c-d Anterior/posterior views of the main pulmonary artery. e Group-averaged OSI (n = 7) comparing extensive pulmonary artery tree (up to 6 th-generation branches) and main arteries (p < 0.05), with localized peaks reaching OSI = 0.16 in dilated regions. Note: Asteriks denote statistical significance, with * P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001

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  Fig. 7. Relative Residence Time (RRT) in two PAH subjects (Cases P4 and P7), demonstrating consistent spatial patterns. a-b 3D visualization cloud images depicting RRT distribution in proximal dilated arteries. c Group-averaged RRT values across segments (p < 0.05). Data from all subjects (n = 7) are shown as median ± standard deviation