Pulmonary arteriography
The x-ray will show normal structures for the age of the patient.
Abnormal results may be due to:
Rubens MB, Dalal P. Pulmonary Circulation and Pulmonary Thromboembolism. In: Grainger RC, Allison D, Adam, Dixon AK, eds. Diagnostic Radiology: A Textbook of Medical Imaging. 5th ed. New York, NY: Churchill Livingstone; 2008:chap 26.