Computed tomography (CT) scan of the chest. The sagittal CT image shows dilation of the main pulmonary artery and enlargement of the right ventricle, consistent with typical idiopathic pulmonary arterial hypertension findings. Dilation of the pulmonary artery results in the narrowing of the space between the pulmonary artery and aorta (red arrow) and causes compression of the recurrent laryngeal nerve.LV: left ventricle; PA: pulmonary artery; RV: right ventricle