Diseases of the central pulmonary arteries are difficult to diagnose. Echographic imaging of the pulmonary arteries can best be done using the suprasternal and transesophageal approach. In pulmonary arterial hypertension, the central pulmonary arteries increase in size, a fact that is used echographically to diagnose pulmonary hypertension. Even when there is volume overload (e.g. in congenital heart disease with a left-to-right shunt), characteristic changes of the pulmonary vessels are observed. Thromboemboli within the pulmonary arteries or thrombotic occlusion and a malignant process, which can lead to an obstruction or compression of the central pulmonary arteries, could be seen with echographic imaging techniques.