Artificial intelligence quantitative Analysis of Pulmonary Morphological Metrics in CTEPH and CTEPD patients: A Single-Center Comparative Study

<bold>Background:</bold> The details of the morphological difference in pulmonary arterial morphology in chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic pulmonary disease (CTEPD) remains unclear. Through artificial intelligence segmentation technology, we aims to identify morphological markers in differentiating CTEPH and CTEPD using CTPA. <bold>Methods:</bold> We retrospectively included a cohort of patients with CTEPH and CTEPD and control subjects from January 2019 to October 2023 in our hospital. The morphological metrics including the pulmonary vessels and airways were quantified on CTPA images by AI digital lung. The difference of pulmonary morphological metrics among three groups were compared, and correlation with hemodynamics were evaluated. <bold>Results:</bold> 116 CTEPH patients, 54 CTEPD patients and 20 control subjects enrolled this study. Pulmonary arterial tortuosity significantly increased in CTEPH patients in comparison with CTEPD patients and control subjects (1.07 [1.06–1.10] vs. 1.10 [1.07–1.14] vs. 1.14 [1.10–1.18], P<0.01). Additionally, small, and small-medium pulmonary arteries were significantly reduced in the CTEPH group compared to CTEPD group (P<0.01), meanwhile the large pulmonary artery were dilatation (P<0.01) with a higher arteriovenous ratio in larger vessels (P<0.01). Notably, the BV10+ AV ratio demonstrated a moderate correlation with mean pulmonary arterial pressure and pulmonary arterial resistance (r=0.66 & r=0.64, p<0.01). <bold>Interpretation:</bold> CTEPH and CTEPD present significant morphological differences in in terms of tortuosity, large, medium-small pulmonary artery and correlated with hemodynamics.