CT angiography, or the spiral CT technique, is a promising minimally invasive method of visualising the arterial vascular system and can be applied in children in whom ultrasound, MRI and/or angiography or cardiac catheterisation cannot be performed, or where an exact diagnosis cannot be made. CT angiography should be considered in special cases as a diagnostic alternative to MRI, ultrasound and angiography. As an example of the possibilities of CT angiography, a case is described in which hypoplasia of the descending aorta was diagnosed and a postoperatively encountered perigraft reaction was demonstrated. Perforation of the blood vessel could be excluded by CT angiography.