Congenital heart disease (CHD) is a common health problem. (Goo, 2003) To plan effective management of congenital heart disease, one needs the clearest understanding of the anatomy and the complex cardiovascular morphology present, especially the extra-cardiac morphology. Echocardiography and cardiac catheterization are the traditional imaging modalities used to diagnose congenital heart disease. (Haramati et al., 2002) Echocardiography is partly limited by the small field of view. Cardiac catheterization is an invasive modality (Berdon, 2000) Helical computed tomography (CT) especially with multi-slice CT technology allows volume acquisition in a short period of time and provides good-quality 3D vascular images, even for neonates and infants. (Ohnesorge et al, 2007)