1Merz E,Welter C.2D and 3D Ultrasound in the evaluation of normal and abnormal fetal anatomy in the second and third trimesters in a level III center.Ultraschall Med,2005,26:9-16.
4Benacerraf BR. The second trimester fetus with down syndrome:detection using sonographic features. Ultrasound Obstet Gynecol, 1996,7 : 147-155.
5Baronciani D, Scaglia C, Corchia C, et al . Ultrasonography in pregnancy and fetal abnormalities: screening or diagnostic test? IPIMC 198621990 register data. Indagine Policentriea Italiana sulle Malformazioni Congenite. Prenat Diagn, 1995, 15 (12): 1101-1108.
6Ploeckinger-Ulm B, Ulm MR, Lee A, Kratochwil A, Bernaschek G. Antenatal depiction of fetal digit with threedimensional ultrasonography. Am J Obstet Gynecol, 1996,175:571-574.
7Kalache kD, Bamberg C, Proquitte H, et al. 3D Multi-slice view in evaluation of fetal anomalies. Ultrasound Med, 2006,25 : 1041- 1049.