Multidetector Computed Tomography for Assessing a Pulmonary Artery Sling in a Pediatric Patient

Abstract

A 4-month-old girl was referred to our department for evaluation of a heart murmur. There was no history of cardiac failure or cyanosis, but there was respiratory difficulty. Examination revealed a grade 3/6 continuous murmur at the right upper sternal border. At echocardiography, an aberrant origin of the left pulmonary artery was demonstrated (Fig. 1). The barium-enhanced esophagogram showed an anterior indentation at the level of the tracheal bifurcation. To assess the pulmonary vascular anatomy, we performed a multidetector computed tomography angiography (MDCTA). In this case we used a 64-detector CT scanner (VCT Lightspeed; GE Healthcare), with 0.625-mm slice thickness. The time required for the study was\10 s. CT at the level of the main pulmonary artery (MPA) showed the anomalous origin of the left pulmonary artery (LPA) from the posterior aspect of the proximal right pulmonary artery (RPA) as it coursed posteriorly between the trachea and the oesophagus to reach the left hilum (Fig. 2). CT described the compressed airway and stenosis of the right branch of the trachea (Fig. 3). The diagnosis of an abnormal origin of the LPA was confirmed at CTA. Surgery with total cardiopulmonary bypass was performed, and the left pulmonary artery was attached to the pulmonary trunk ventrally to the trachea. In patients with a suspected pulmonary artery sling, conventional angiography is the current diagnostic standard. CTA is a novel imaging tool that provides good anatomic detail information, with the advantage of being noninvasive, and is therefore very useful for the diagnosis of pulmonary vascular anomalies in pediatric patients [2]. The literature demonstrated the powerful ability of CTA to delineate the exact location and morphology of the pulmonary artery and trachea [1, 3].