Shimizu K, et al. - This study is performed to explore the effect of computed tomography-derived pulmonary vasculature metrics in the diagnosis and haemodynamic assessment of pulmonary arterial hypertension. Pulmonary artery to the aorta (PA/Ao), %CSA<5, and ostial diameter of the right inferior pulmonary vein (PVD) are valuable non-invasive pulmonary vasculature metrics, both alone and in combination, for diagnosis and haemodynamic evaluation of pulmonary arterial hypertension (PAH).