Systemic-pulmonary shunt – a rare cause of filling defects in the pulmonary arteries

Abstract

The normal lungs have two distinct circulations with different origins and functions. The pulmonary circulation is accomplished by the pulmonary arteries, while the systemic one mainly by the bronchial arteries. The vascular communications between the systemic and pulmonary circulations are small and include precapillary vessels, which cannot be visualized on computed tomography (CT). The systemic circulation of the lungs can increase in different pulmonary and heart diseases – the vessels dilate and become tortuous, new anastomoses appear. All these changes can easily be visualized in CT as opposed to the normal precapillary communications. We present a clinical case of an 85-year-old man with a history of chronic obstructive pulmonary disease, who was admitted to the Cardiology Department with acute dyspnea. Laboratory findings revealed increased D-dimer because of which CT pulmonary angiography was performed. The examination showed unusual filling defects in the pulmonary arteries with emphysema and pulmonary fibrosis. CT aortography was accomplished and proved systemicpulmonary shunt with dilated and tortuous bronchial arteries.