Scimitar Syndrome

Scimitar, or pulmonary venolobar, syndrome is a rare but well-known congenital cardiovascular defect that includes a hypoplastic right pulmonary artery and right lung, which leads to displacement of cardiac structures into the right hemithorax, anomalous systemic arterial supply to the right lung, and a characteristically curved anomalous right pulmonary vein that drains into the inferior vena cava and resembles the curved Middle Eastern sword “scimitar.”1,2 A variety of congenital thoracic abnormalities are associated with this specific type of partial anomalous pulmonary venous return.3Imaging, and specifically findings from magnetic resonance imaging, in an 18-month-old male (11 kg body weight) with known congenital right pulmonary venolobar syndrome with increasingly frequent cyanotic episodes are presented. Findings on chest radiography and contrast-enhanced computed tomography of the chest performed when the patient was 4 days old included right lung hypoplasia and partial anomalous pulmonary venous return with scimitar vein to the supradiaphragmatic inferior vena cava (Figure 1). Echocardiography identified the scimitar vein and an atrial septal defect. Cardiac magnetic resonance imaging, including 4-dimensional flow-sensitive magnetic resonance imaging, confirmed these findings but also identified additional cardiovascular abnormalities, including an additional partial anomalous pulmonary venous return from the upper right lung to the superior vena cava and an anomalous systemic artery from the upper abdominal aorta to the lower right lung (Figure 2). Further comprehensive analysis …