Three-dimensional (3D) power Doppler ultrasound facilitates the evaluation of fetal cardiac blood flow and peripheral vascular trees, fetal organ blood flow, placental vasculature and blood flow, and maturation of the uterine cervix. With the recent advances in 3D power Doppler ultrasound as well as quantitative 3D power Doppler histogram analysis, quantitative and qualitative assessments of the vascularization and blood flow of fetal organs, the placenta, and uterine cervix have become feasible. This technique may assist in evaluation of the fetal cardiovascular system and feto-placental function, and offer potential advantages relative to conventional two-dimensional power Doppler ultrasound assessments. In this chapter, we discuss the present and future applicability of 3D power Doppler ultrasound in obstetrics. 3D power Doppler ultrasound may become an important modality in future research on fetal and placental blood flow, and assist in prenatal diagnosis of the fetal and placental vascular abnormalities.
Keywords: 2D power Doppler, 3D power Doppler, Fetal heart, Fetal organ blood flow, Fetal peripheral circulation, Placenta, Placental vascular sonobiopsy, Umbilical cord, Uterine cervix, Vascular index.