Three dimensional power Doppler of the placenta and its clinical applications

Does a Caesarean Section Scar Affect Placental Volume, Vascularity and Localization?

Caesarean section is associated with an increased risk of abnormal placental implantation and adverse pregnancy outcomes in subsequent pregnancies. Besides the placenta accrete spectrum, only a few of the previous studies focused on other placental development alterations in the scarred uterus. We assessed placental development deviations in the uterus with a Caesarean section scar by evaluating placental volume (PV) and vascular flow indexes. From 1 January 2021 until 31 March 2022, placental volumes and vascularization indexes (VI, FI, VFI) were prospectively measured by 3D power Doppler and VOCAL techniques in 221 patients attending the first trimester screening program. We also calculated the placental quotient to standardize PV to the gestational age. No statistically significant differences in the values of placental volume, placental quotient and placental vascularization indexes were detected between women with previous Caesarean section delivery or women with vaginal delivery. FI was significantly lower in nulliparous in the first trimester. The results of our study suggest that 3D placental evaluation was not able to detect placental development alteration in the uterus with a Caesarean section scar. Future research needs to verify whether 3D power Doppler and Vocal techniques can provide more information if used in an earlier gestational age.

Evaluation of placental growth potential and placental bed perfusion by 3D ultrasound for early second-trimester prediction of preeclampsia

PURPOSE

This study aimed to investigate whether placental parameters measured by three-dimensional ultrasound are associated with preeclampsia (PE) and small-for-gestational-age (SGA).

METHODS

In total, 1163 pregnancies at 11-14 weeks of gestation were recruited between October 8, 2020, and April 30, 2021. Placenta volume (PV), placental bed vascularization flow index (PBVFI), and uterine arteries pulse index (UtA-PI) were measured. Placental quotient (PQ = PV/weeks of gestation) was calculated. All participants were re-examined 4 weeks later. The placental volume growth rate (PVGR = placental volume difference between the two examinations/interval days) was also calculated. Patients were divided into four groups by the gestational age at the onset of PE and birth weight: early-onset PE (E-PE, n = 18), late-onset PE (L-PE, n = 36), isolated SGA5 (birth weight less than the fifth percentile for gestational age without PE, n = 9), and unaffected (n = 1100) groups.

RESULTS

A predictive model for E-PE was established, which consisted of unnatural conception, chronic hypertension, PBVFI (of second examination), and PVGR for E-PE; 94.4% sensitivity and 96.7% specificity by receiver operating characteristic curve analysis.

CONCLUSIONS

Overall, decreased placental growth potential and low placental bed perfusion in the early second trimester have potential in predicting E-PE.

Emerging placental biomarkers of health and disease through advanced magnetic resonance imaging (MRI)

Placental dysfunction is a major cause of fetal demise, fetal growth restriction, and preterm birth, as well as significant maternal morbidity and mortality. Infant survivors of placental dysfunction are at elevatedrisk for lifelong neuropsychiatric morbidity. However, despite the significant consequences of placental disease, there are no clinical tools to directly and non-invasively assess and measure placental function in pregnancy. In this work, we will review advanced MRI techniques applied to the study of the in vivo human placenta in order to better detail placental structure, architecture, and function. We will discuss the potential of these measures to serve as optimal biomarkers of placental dysfunction and review the evidence of these tools in the discrimination of health and disease in pregnancy. Efforts to advance our understanding of in vivo placental development are necessary if we are to optimize healthy pregnancy outcomes and prevent brain injury in successive generations. Current management of many high-risk pregnancies cannot address placental maldevelopment or injury, given the standard tools available to clinicians. Once accurate biomarkers of placental development and function are constructed, the subsequent steps will be to introduce maternal and fetal therapeutics targeting at optimizing placental function. Applying these biomarkers in future studies will allow for real-time assessments of safety and efficacy of novel interventions aimed at improving maternal-fetal well-being.

Normative placental structure in pregnancy using quantitative Magnetic Resonance Imaging

INTRODUCTION

To characterize normative morphometric, textural and microstructural placental development by applying advanced and quantitative magnetic resonance imaging (qMRI) techniques to the in-vivo placenta.

METHODS

We enrolled 195 women with uncomplicated, healthy singleton pregnancies in a prospective observational study. Women underwent MRI between 16- and 40-weeks' gestation. Morphometric and textural metrics of placental growth were calculated from T2-weighted (T2W) images, while measures of microstructural development were calculated from diffusion-weighted images (DWI). Normative tables and reference curves were constructed for each measured index across gestation and according to fetal sex.

RESULTS

Data from 269 MRI studies from 169 pregnant women were included in the analyses. During the study period, placentas undergo significant increases in morphometric measures of volume, thickness, and elongation. Placental texture reveals increasing variability with advancing gestation as measured by grey level non uniformity, run length non uniformity and long run high grey level emphasis. Placental microstructure did not vary with gestational age. Placental elongation was the only metric that differed significantly between male and female fetuses.

DISCUSSION

We report quantitative metrics of placental morphometry, texture and microstructure in a large cohort of healthy controls during the second and third trimesters of pregnancy. These measures can serve as normative references of in-vivo placental development to better understand placental function in high-risk conditions and allow for the early detection of placental mal-development.

Feasibility of three dimensional power Doppler ultrasonography methods to assess placental perfusion

OBJECTIVES

Given the crucial role of the placenta in establishing a healthy pregnancy, reliable non-invasive methods to measure placental perfusion are desirable. The aim of this study is to determine the reproducibility and potential bias in different three-dimensional power Doppler (3DPD) methods assessing placenta perfusion.

METHODS

Ten singleton pregnancies around 16 weeks of gestation, with an anteriorly located placenta and centrally inserted umbilical cord were included in this study. Eight different combinations of a specific placental sweep and sonobiopsy method were used to evaluate placental perfusion. Vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) were determined offline using the 4D-view program. Reproducibility and repeatability of the methods, expressed as correlation coefficients and Bland-Altman mean differences, were calculated. Differences between sampling methods were analyzed using t-test or Mann-Whitney U test.

RESULTS

Intra- and inter-class correlation coefficient (CC) was highest when using a spherical centrally placed sonobiopsy of 2 cm³ in a whole placenta sweep (method 1; IntraCC VI 0.985, FI 0.769, VFI 0.993, InterCC VI 0.986, FI 0.784, VFI 0.987). Overall, intraCCs were higher compared to interCCs. Lowest mean differences in VI and FI were found comparing spherical to manual sonobiopsies, whereas the mean differences in VFI were lowest when comparing central versus peripheral located sonobiopsies. Comparing the three vascular indices, best median intra- and interCC and lowest mean differences were found for VFI.

CONCLUSIONS

Three dimensional placental vascularization analysis showed best reproducibility using whole placental sweep volume and centrally located, spherical sonobiopsy of 2 cm³.

The Diagnostic Value of 3D Power Doppler Ultrasound Combined With VOCAL in the Vascular Distribution of Breast Masses

RATIONALE AND OBJECTIVES

This study uses a three-dimensional energy Doppler technique combined with the Virtual Organ Computer-aided Analysis (VOCAL) method in order to determine the diagnostic threshold of blood flow index in breast tumors to provide a reference for evaluation and treatment options.

MATERIALS AND METHODS

We collected 322 solid lesions which had been operated. Each lesion met the definite pathological diagnosis; collected lesions included 262 cases of benign lesions and 60 cases of malignant lesions. All examinations were performed by using GE LOGIQ E9 with VOCAL software. Volume and four distinct vascular indices of gray mean (MG), power mean, ratio (R), and vascular flow index (VFI) were calculated by using the VOCAL software. Sampling and calculation were repeated three times and the mean value was calculated.

RESULTS

The average age and power of the malignant group were greater than those of the benign group, ie p < .01 which had significant differences. The gray mean of the malignant group was lower than that of the benign group, ie p > .05 which had no significant differences between benign and malignant groups. The ratio, vascular flow index and volume had significant differences, i.e. p < .01. The area under the receiver operating characteristic curve (AUC) were 0.864, 0.830, 0.800, 0.758, and 0.764 for age, power, ratio, vascular flow index, and volume, respectively. The research indicators were higher than 50% of the curve showing their diagnostic value. The cut-off points of age, power, ratio, vascular flow index, and volume were 37.5, 26.56, 0.031, 0.846, and 1.75, respectively. Their corresponding sensitivity were 93.3%, 75%, 81.7%, 68.3%, 63.3%, and the specificity were 68.7%, 81%, 70.2%, 75.6%, and 81.7%, respectively. Comparison of vascular indices combined with the Breast imaging reporting and data System (BI-RADS) score and simple BI-RADS method, the AUC of power + BI-RADS, ratio + BI-RADS, VFI + BI-RADS, and BI-RADS alone are 0.928, 0.903, 0.895, and 0.796, respectively, which were higher than 50% of the curve. Sensitivity was 81.7%, 80%, 88.3%, 86.7%, and specificity was 88.5%, 85.5%, 77.1%, 69.5%, respectively. The power + BI-RADS method has the highest AUC among these three methods.

CONCLUSIONS

Quantitative measurement of blood flow and blood vessel distribution in breast tumors by three-dimensional power Doppler ultrasound combined with the VOCAL method is more accurate and sensitive than the traditional two-dimensional ultrasound. And this method has potential promising applications in many current active research areas, such as the studies of random distribution of intratumoral blood vessels or the normalization of tumor blood vessels. Three-dimensional power Doppler ultrasound combined with the VOCAL method provides a new approach to achieving accurate judgments and the method evaluates the curative effect in breast cancer patients.

Maternal Utero-Placental Perfusion Discordance in Monochorionic-Diamniotic Twin Pregnancies with Selective Growth Restriction Assessed by Three-Dimensional Power Doppler Ultrasound

Background

The aim of this study was to assess the correlation between selective growth restriction (sGR) and co-twin utero-placental perfusion discordance by using three-dimensional power Doppler (3DPD).

Material/Methods

We prospectively recruited 60 sGR and 64 normal monochorionic-diamniotic (MCDA) twin pregnancies. Vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were assessed by 3DPD, while umbilical artery pulsatility index (UA-PI), middle cerebral artery peak systolic velocity (MCA-PSV), pulsatility index (MCA-PI), and cerebroplacental ratio (CPR) were assessed by conventional Doppler imaging.

Results

In sGR co-twins, the VI, FI, VFI, MCA-PI, and CPR were significantly lower, while the UA-PI and MCA-PSV were significantly greater, in the smaller fetuses compared with the larger fetuses; significant differences were also observed in the VI, FI, VFI, CPR, and UA-PI in normal co-twins. Compared with the appropriately grown twins, the discordances of the VI, FI, VFI, UA-PI, MCA-PI, and CPR were increased in the sGR cohort. The discordances of the VI, FI, VFI, UA-PI, MCA-PI, and CPR were associated with birthweight discordance, and the FI discordance and CPR discordance were independently associated with sGR. The combination of the FI and CPR discordance showed a higher predictive accuracy for sGR, with an area under the ROC curve of 0.813, and a sensitivity and specificity of 68.33% and 85.94%, respectively.

Conclusions

MCDA twin pregnancies with birthweight discordance presented utero-placental perfusion deterioration assessed by 3DPD prior to sGR diagnosis. Co-twin utero-placental perfusion discordance was significantly correlated with growth discordance, and this correlation was more predictive of sGR when 3DPD was combined with conventional Doppler imaging.

Methodology of preparation of corrosive specimens from human placenta - A technical note

Detailed knowledge of the anatomy of human placenta vessels is clinically essential and requires the use of many different anatomical and histological techniques. One of the interesting methods of visualising vessels is the corrosion technique. It enables spatial visualisation of the vascular network of the analysed organ. The authors present a developed, own method of preparing the corrosive preparations from human placenta. They underline the advantages and disadvantages of this technique. They describe solutions aimed at reducing the costs of the process. They show that corrosion technology enables relatively fast and inexpensive visualisation of arterial and venous vessels of the human placenta.