1. From the Institute for Diagnostic and Interventional Radiology (R. Bastkowski, K.W., D.M., D.G.) and Department of Pediatric Cardiology, Heart Centre (R. Bindermann, K.B.), University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Str 62, D-50937 Cologne, Germany; and Philips Healthcare Hamburg, Hamburg, Germany (K.W.).