Pulmonary artery sling diagnosed by magnetic resonance imaging

INTRODUCTION The pulmonary sling is a rare congenital vascular anomaly of the left pulmonary artery which originates more posteriorly to the right pulmonary artery, runs above the main pulmonary bronchus and reaches the left hilum passing between trachea and esophagus.1*2 Morbility and mortality are primarily associated with cardiovascular and respiratory anomalies. The pulmonary sling is a frequent cause of respiratory insufficiency with cough, dyspnea and stridor.3 Barium esophageal radiographs show a mass between trachea and esophagus which can be confimed at angiographic examination of the pulmonary artery.4*5 A clear diagnosis, however, is not always accomplished with these techniques. Computed tomography (CT) and magnetic resonance (MR) are reported in literature as valuable diagnostic techniques in the study of cardiovascular diseases. Moreover, MR has proven to be useful in cardiac imaging.6-8 We report one case of pulmonary artery sling studied with MR. CASE RJZPORT A 6-month-old baby was submitted to our observation. He had a history of respiratory distress at birth and cyanosis which rapidly resolved. Subsequently, he was in an apparent good health apart from a slight growth retardation. Three days before MR examination, he presented with dyspnea, laryngeal stridor and cyanosis. A mild decrease in the left lung perfusion was observed at the first chest radiograph. Transthoracic doppler echocardiography showed presence of a wide atria1 septal defect. An anomalous pulmonary artery with distal bifurcation was also observed. On the basis of these finding