7. Laboratory findings and other examinations a Chest X-ray the sign of pulmonary arterial hypertension the width of right-inferior pulmonary artery>15mm extruding of pulmonary artery segment enlargement of right ventricle7. Laboratory findings and other examinations a. Chest X-ray the sign of pulmonary arterial hypertension the width of right-inferior pulmonary artery>15mm extruding of pulmonary artery segment enlargement of right ventricle