Figure 9b. Double inlet left ventricle with d-transposition of the great arteries, observed at ECG-gated CT performed to supplement postoperative echocardiography in a 30-year-old man after surgical banding of the common pulmonary artery. (a) Thin-section reformatted image along the long axis of the heart shows connection of the left atrium (LA) and right atrium (RA) through a left-sided valve (LSV) and a right-sided valve (RSV), respectively, to a dominant ventricle (DV, morphologic left ventricle). (b) Thin-section oblique sagittal image demonstrates a subaortic outlet chamber (SOC) connected via a bulboventricular foramen (*) to the subpulmonary ventricle (the dominant ventricle in a). There is no atrioventricular connection to the subaortic outlet chamber. Banding of the common pulmonary artery was performed to protect the lung from high systemic blood flow and pressure. The great arteries are in parallel position (d-transposition): The pulmonary artery arises from the morphologic left single ventricle, and the aorta arises from the subaortic outlet chamber. AV = aortic valve, PV = pulmonary valve.