Transposition of great arteries
 Discussion of Transposition of great arteries
- Transposition of the great arteries is the most common cyanotic congenital heart lesion found in neonates
- It accounts for 5%–7% of congenital cardiac malformations.
- It is most common in infants of diabetic mothers.
- It is isolated in 90% of those affected and rarely is associated with a syndrome or an extracardiac malformation.
- Transposition of the great arteries is produced by a ventriculoarterial discordance in which the aorta arises from the morphologic right ventricle and the pulmonary artery arises from the morphologic left ventricle.
- To sustain life, a communication (eg, a patent foramen ovale, atrial septal defect, ventricular septal defect, or a combination of these) must be present between the systemic and the pulmonary circulation, in addition to systemic collateral arteries.
 Imaging Findings for Transposition of great arteries
- In the normal anatomy, the aorta is anterior to and at the right of the pulmonary artery
- In transposition of the great arteries, the pulmonary artery is situated to the right of its normal location and is obscured by the aorta on frontal chest radiographs.
- This malposition, in association with stress-induced thymic atrophy and hyperinflated lungs, results in the apparent narrowing of the superior mediastinum on radiographs, the most consistent sign of transposition of the great arteries.
- The cardiovascular silhouette varies from normal in the first few days after birth to enlarged and globular, with the classic egg on a string appearance.
 See Also
 External Links
 References for Transposition of great arteries
- Emma C. Ferguson, Rajesh Krishnamurthy, and Sandra A. A. Oldham. Classic Imaging Signs of Congenital Cardiovascular Abnormalities. RadioGraphics 2007 27: 1323-1334.