Congenitally corrected transposition

Congenitally corrected transposition with the aorta in the left position where the pulmonary artery should be. The identification of the ascending aorta is made by the bulge in the pulmonary artery smoothly running into the aortic knuckle at the left upper edge of the mediastinum. The right pulmonary artery is slightly dilated and this suggests that pulmonary stenosis could be present. Note that post stenotic dilatation involves the right and not the left pulmonary artery when the great arteries are malposed or transposed.