Pulmonary angiography allows x-ray visualization of the pulmonary vasculature after injection of an iodinated contrast medium into the pulmonary artery or a branch of this great vessel. Contrast medium is injected through a catheter that has been inserted into the vascular system, usually through the femoral vein. It is one of the definitive tests for pulmonary embolism, but it is also useful for evaluating other types of pulmonary vascular abnormalities. It is definitive for peripheral pulmonary artery stenosis, anomalous pulmonary venous drainage, and pulmonary fistulae. Hemodynamic measurements during pulmonary angiography can assist in the diagnosis of pulmonary hypertension and cor pulmonale.