Various congenital and acquired anomalies may affect the pulmonary arteries in adult patients. Congenital anomalies (proximal interruption, anomalous origin of the left pulmonary artery [pulmonary artery sling], and idiopathic dilatation of the pulmonary trunk) are usually found incidentally at chest radiography or computed tomography (CT). Acquired anomalies include diffuse or focal enlargement of the arteries because of pulmonary hypertension, aneurysm, and intravascular pulmonary metastasis; decreased arterial diameter because of bronchial carcinoma, mediastinal fibrosis, and Takayasu arteritis; and intraluminal filling defects due to pulmonary thromboembolism and pulmonary artery sarcoma. An awareness of the radiologic manifestations of the disease entities and potential pulmonary artery complications secondary to infection or vasculitis may enable an early diagnosis. CT angiography is becoming the standard method for evaluating patients in whom the presence of pulmonary embolism is suspected. CT assessment of the extent of heart effects in patients with pulmonary hypertension and pulmonary embolism is particularly important because such effects largely determine the prognosis.
(c) RSNA, 2006.