Doppler evaluation of normal and abnormal placenta

Abstract

Doppler techniques are needed for the evaluation of the intraplacental circulation and can be of great value in the diagnosis of placental anomalies. Highly sensitive Doppler techniques can differentiate between the maternal (spiral arteries) and fetal (intraplacental branches of the umbilical artery) components of the placental circulation and assist in the evaluation of the placental functional units. A reduced number of placental functional units can be associated with obstetric complications, such as fetal growth restriction. Doppler techniques can also provide information on decidual vessels and blood movement. Abnormal decidual circulation increases the risk of placenta accreta.Doppler evaluation of the placenta greatly contributes to the diagnosis and clinical management of placenta accreta, vasa previa, placental infarcts, placental infarction hematoma, maternal floor infarction, massive perivillous fibrin deposition and placental tumors. However, it has a limited role in the diagnosis and clinical management of placental abruption, placental hematomas, placental mesenchymal dysplasia and mapping of placental anastomoses in monochorionic twin pregnancies.

Imaging of placental circulations by 4D sonography with high‐definition flow and spatiotemporal image correlation technology

“…The results of the present report support that STIC volume acquisition in HDF, displayed in glass‐body mode is likely a potential technique to study the placental function unit, in addition to the conventional 2D/3D HDFI and MVFI 3,7,8,17,18 . However, visualization by STIC may be affected by motion artifacts, bloom artifact, uterine contraction and thick maternal abdominal wall 3 .…”

“…2 The results of the present report support that STIC volume acquisition in HDF, displayed in glass-body mode is likely a potential technique to study the placental function unit, in addition to the conventional 2D/3D HDFI and MVFI. 3,7,8,17,18 However, visualization by STIC may be affected by motion artifacts, bloom artifact, uterine contraction and thick maternal abdominal wall. 3 Further studies are required to investigate whether STIC volume acquisition, with mechanical or electronic matrix probe, can allow qualitative and quantitative assessment of the development of the placental functional unit in normal and abnormal pregnancies.…”

“…In the fetoplacental circulation, chorionic surface vessels and the intraplacental branches (IPB) of the umbilical artery were clearly displayed from STIC volumes (Video S1). The term “intraplacental branches” is used because there is no defined nomenclature for these vessels 3 . Primary, secondary and tertiary order branches were visualized (Figure 1A).…”

“…The term "intraplacental branches" is used because there is no defined nomenclature for these vessels. 3 Primary, secondary and tertiary order branches were visualized (Figure 1A). Both red and blue color signals were found inside these branches because of the presence of both arterial and venous flow.…”

“…It is a challenge to non‐invasively characterize intraplacental blood flow without motion artifacts. Conventionally, two‐ (2D) or three‐ (3D) dimensional high‐definition flow imaging (HDFI) or microvascular flow imaging (MVFI) are used to examine the placenta circulations, but there are limitations of these imaging techniques 3 . In particular, static 3D ultrasound images do not provide dynamic information about blood flow.…”