Imaging description

A newborn infant was noted to have moderate tachypnea and cyanosis at birth. A chest radiograph (Fig. 30.1a) demonstrated patchy opacity in the right upper lobe, question atelectasis or pneumonia. There was a slightly narrow mediastinum with an oval-shaped cardiac silhouette (“egg on a string” appearance). Pulmonary vascular markings appeared mildly increased but the main pulmonary artery segment was concave; the possibility of transposition of the great arteries (TGA) was raised and confirmed on cardiac echo. A non-restrictive secundum atrial septal defect (ASD) was present with no other shunt found. A follow-up chest radiograph at five days of age demonstrated an increase in heart size and prominence of pulmonary vascularity (Fig. 30.1b). An MR examination was obtained to further evaluate anatomy and ventricular size and function. This confirmed transposition of the great arteries (right ventricle connecting to aorta and left ventricle connecting to pulmonary artery) with an anterior and rightward position of the ascending aorta relative to the main pulmonary artery, ASD with no other connection, and normal sized ventricles with good biventricular function (Fig. 30.1c–e). The baby underwent an arterial switch procedure at 10 days of age.