The study of morphology and circulation of early embryo by three-dimensional ultrasound and power Doppler

Three-dimensional (3-D) ultrasound plays an important role in obstetrics pr edominantly for assessing fetal anatomy. Presenting volume data in a standa rd anatomic orientation assists both ultrasonographers and pregnant patient s to recognize anatomy more readily. Three-dimensional ultrasound is advant ageous for the study of normal embryonic and/or fetal development, as well as providing information for families at risk for specific congenital anoma lies by confirming normality. This method offers advantages in assessing th e embryo in the first trimester as it is able to obtain multiplanar images through endovaginal volume acquisition. Rotation of the embryo and close sc rutiny of the volume allow the systematic review of anatomic structures suc h as cord insertion, limb buds, cerebral cavities, stomach and bladder. Usi ng this modality one can easily obtain the volumes of the gestational sac a nd yolk sac and can evaluate their relationship to prediction of pregnancy outcome. Three-dimensional power Doppler sonography has the potential to st udy process of placentation and evaluate the development of the embryonic a nd fetal cardiovascular systems. Three-dimensional ultrasound imaging in vi vo compliments pathologic and histologic evaluation of the developing embry o, giving rise to a new term: 3-D sonoembryology. Rapid technological devel opment will allow real-time 3-D ultrasound to provide improved and expanded patient care on the one side, and increased knowledge of developmental ana tomy on the another.