1. Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology; David Geffen School of Medicine at UCLA; Los Angeles California USA
2. Fetal Diagnostic Centers, Pasadena, Tarzana, and Lancaster; California USA
3. TomTec Imaging Systems GmbH; Munich Germany
4. Division of Pediatric Cardiology, Department of Pediatrics; Mattel Children's Hospital, David Geffen School of Medicine at UCLA; Los Angeles California USA