彩色多普勒超声诊断帆状胎盘和血管前置的临床价值及漏诊误诊原因分析

目的 探讨产前彩色多普勒超声诊断帆状胎盘及血管前置的临床价值及漏诊和误诊原因分析。方法 回顾性分析2015年1月~2018年7月我院行产前彩色多普勒超声筛查946例孕妇的彩色多普勒声像图及临床特点,分析帆状胎盘和血管前置的超声诊断情况、影像学特点及妊娠结局。结果 共946例孕妇中,产科证实帆状胎盘117例,超声诊断帆状胎盘106例,漏诊11例,误诊7例,漏诊率:9.40%（11/117）,误诊率:0.84%（7/829）,诊断符合率:98.10%（928/946）;产科证实血管前置19例,超声诊断血管前置16例,漏诊3例,误诊3例;漏诊率:15.79%（3/19）,误诊率:0.32%（3/727）,诊断符合率:99.37%（940/946）。帆状胎盘彩色多普勒超声显示脐带入口在胎盘边缘的游离胎膜内,经羊膜和绒毛膜之间进入胎盘;血管彩色多普勒超声显示胎膜血管位于胎儿先露前方跨越宫颈内口或者接近宫颈内口。有69.91%（79/113）的超声帆状胎盘孕妇选择剖宫产,另外30.09%（34/113）选择顺产;有19例产前超声诊断为血管前置孕妇均选择剖宫产,其中5例胎膜早破急诊剖宫产手术,但新生儿情况良好。结论 彩色多普勒超声能较好的显示胎盘形状、胎盘脐带插入口位置及宫颈内口血管情况,提高诊断帆状胎盘及血管前置诊断率,改善妊娠结局,降低围生期胎儿死亡率,但因各种因素影响,存在一定漏诊和误诊。     

216例胎儿泌尿系畸形超声诊断分析

目的探讨超声诊断胎儿泌尿系统畸形声像图特征和临床应用价值。方法应用彩色多普勒超声对产前诊断为泌尿系统畸形的胎儿进行图像分析并与产后结果对照研究。结果胎儿泌尿系统畸形216例,其中肾积水176例,婴儿型多囊肾6例,成人型多囊肾5例,多囊性发育不良肾19例,肾缺如6例,盆腔异位肾2例,重复肾2例。结论产前超声（彩色多普勒）在诊断胎儿泌尿系统畸形上是一种成熟的影像技术,对胎儿预后判断,指导临床医生及时采取相应产前措施,对优生优育和新生儿早期治疗均有十分重要的临床实际意义。     

超声多谱勒对脐动脉血流频谱S/D值的研究——附140例报导

近年来超声多普勒对脐带动脉血流频谱的研究已成为一种判断宫内胎儿健康状况的公认手段,脐动脉血流频谱收缩期速度峰值和舒张期速度最低值的比值(S/D)是目前最常使用的一种参数,用以估价胎盘功能和预示胎儿发育情况,我们自1990年2月至1991年5月对140例孕妇在脐带的三个不同部位进行超声多普勒检查,在各部位分别测量S/D值并进行分析比较。     

早孕期三维能量多普勒超声对胎儿生长受限的预测价值分析

目的:探讨三维能量多普勒超声指标对胎儿生长受限(FGR)的预测价值。方法:前瞻性连续收集2016年12月~2017年12月在南方医科大学南方医院进行产前早孕NT检查的正常单胎妊娠孕妇231例作为研究对象,并采集早孕期胎盘三维能量多普勒容积数据存至硬盘,对所有孕妇进行随访至出生后,根据随访诊断结果分为FGR组(n=11例)和正常组(n=220例)。利用GE 4DView软件进行离线测量胎盘体积并得出胎盘血管指数(包括胎盘血管化指数、血流指数、血管化-血流指数)。结果:FGR组胎盘血管化指数、血管化-血流指数均显著低于正常组(P0.05),差异有统计学意义(P0.05)。结论:早孕期胎盘三维能量多普勒超声指标对于FGR的早期预测有重要价值意义,为早期预测FGR提供量化指标,值得推广应用。     

脐动脉血流速度指数(S/D)对胎儿窘迫的预测

胎儿以脐动脉血流收缩期峰值与舒张末期最低速度之比值（S／D）作为脐动脉血流阻抗的测定指标，判断胎盘功能和胎儿血流情况。我院应用彩色多普勒超声。监测胎儿脐动脉血流S／D比值，预测胎儿窘迫，胎盘功能，报告如下。     

彩色多普勒超声对胎儿脐动脉血流分析的临床价值

目的与方法近年来国内外有关应用彩色多普勒超声检查胎儿脐动脉血流的报道日渐增多,已成为宫内胎儿生长发育健康状况的评定方法之一,现就我院收集近年来对136例产科晚期妊娠胎儿脐动脉血流的S/D值、血流量、RI、PI值预测胎儿宫内发育情况作一分析.结果正常组102例,平均S/D值2.47,RI 0.55,PI 0.95,脐动脉血流量400ml/min,出生体重2700～4100g.宫内发育迟缓(IUGR)组34例,平均S/D值3.23,R I0.75,PI 1.30,脐动脉血流量264ml/min,出生体重小于2500g.胎儿宫内窘迫1例,S/D值39.6,RI 1.72,PI 2.96,脐动脉血流量104ml/min,死胎体重1250g.由此可见,脐动脉血流S/D值、RI、PI值是反映胎盘血管阻力,判断胎盘功能的一个较好参数,脐动脉血流量与胎儿的生长发育有关.     

利用超声图像的分形特征评估妊娠期胎盘功能

利用超声仪器得到孕妇妊娠期的胎盘B型超声图像然后根据分数布朗运动模型对图像进行分形处理。提取出用以胎盘分级的分形特征参数，并结合临床医学专家的判断，利用模糊分类法，建立起胎盘功能的自动分级规则，通过106例胎盘图像的分析。结果表明：胎盘B型超声图像的分形特征可以有效地表征胎盘的功能状况，从而使胎盘功能的无损自动分级成为可能，因此有较好的临床应用前景。     

产前超声诊断11例妊娠合并血管前置病例分析

目的探讨产前超声检查诊断血管前置的意义及方法。方法回顾性分析11例妊娠合并血管前置产前超声声像图表现及胎儿结局。结果 11例血管前置中,诊断符合7例(其中中孕诊断5例,晚孕诊断2例),择期剖宫产7例,无围产儿死亡;漏诊3例(其中中孕1例、晚孕2例),误诊2例(均为晚孕),因胎儿窘迫、孕妇阴道流血急诊剖宫产4例,其中两例新生儿窒息。结论中孕是诊断血管前置的最佳时期,经腹超声检查胎盘、胎盘脐带插入口、宫颈内口并叠加彩色多普勒是诊断血管前置的常规方法,对宫颈内口显示不满意时结合经阴道或经会阴彩色多普勒超声检查可有效降低血管前置漏诊误诊率,有效改善围产儿结局。     

轮状胎盘超声特点及诊断价值

目的：探讨孕期宫腔轮状胎盘声像特点及超声诊断价值。方法收集2000~2012间经病理证实的35例轮状胎盘的资料,分析其临床资料,总结其声像图特征。结果轮状胎盘二维超声图像表现胎盘边缘呈片状或索带状突向羊膜腔中等回声,突起部分长短、厚薄、宽度不等,突出部分未探及血流信号。片状或索带状结构与胎儿不相连,胎儿活自如。结论超声能反应轮状胎盘病理基础,可补充产前超声检查信息,研究其超声特性有助于鉴别诊断及对晚孕期胎儿的监测及指导具有重要的临床意义。     

心房钠尿肽在产科领域的研究进展

心房钠尿肽是一种具有强大的利钠、利尿、扩张血管作用的肽类激素,在胎盘和胎膜组织有丰富的表达,对维持妊娠期间正常的子宫胎盘循环和胎儿生长发育中起重要作用。目前研究发现,心房钠尿肽与妊娠期高血压疾病、胎儿生长受限、胎儿宫内窘迫等一些产科疾病关系密切。心房钠尿肽浓度变化对于这些疾病的诊断、治疗、及预后判断均起一定的作用。不久的将来,心房钠尿肽作为一种药物在临床的应用将越来越广。     

The effect of heterologous antisera on embryonic development. XIII. Lack of effect of antisera to alpha fetoprotein

This investigation was carried out to determine whether heterologous antisera to alpha fetoprotein (AFP) are embryotoxic to developing rat embryos. Homogeneous rat AFP was isolated and antisera directed against this glycoprotein were produced in rabbits, horse and goat. The effect of the antisera on embryonic development was examined by injecting the antisera intraperitoneally into pregnant rats on the ninth, eleventh and thirteenth days of gestation. The results demonstrated that there was no evidence of increased incidence of fetal abnormalities in 472 surviving fetuses of 42 injected rats. There was no evidence of increase embryonic death or retardation of intrauterine growth following administration of the antisera on the ninth, eleventh and thirteenth days of gestation. The localization of the injected antisera was examined by the indirect immunofluorescent method. The results showed that the heterologous AFP antibodies localized specifically in the visceral yolk sac placenta. No antibody localization was observed in the embryo proper or the chorioallantoic placenta. It is speculated that the localization of AFP antibodies in the visceral yolk sac does not interfere with the embryotrophic function of the visceral yolk sac placenta.     

基于X射线造影图像的冠状动脉运动分析

我们提出了一种采用X射线造影图像对冠状动脉的非刚性运动进行分析的方法,通过寻找两帧图像之间血管上点的对应关系,得到各点的运动向量。匹配中同时考虑了运动场的光滑性和血管的形状相似度。同时由于变形前后血管的长度可能不同,因而加入了对无匹配部分的处理,保证了匹配的均匀性。采用动态规划完成对最优匹配的搜索,减少了计算量。采用仿真图像和临床得到的造影图像分别对该算法进行了验证,对仿真图像运动向量估计的均方根误差在1个像素左右。对临床造影图像的实验也得到了较为满意的结果。     

Superovulation alters the expression of imprinted genes in the midgestation mouse placenta

Imprinted genes play important roles in embryonic growth and development as well as in placental function. Many imprinted genes acquire their epigenetic marks during oocyte growth, and this period may be susceptible to epigenetic disruption following hormonal stimulation. Superovulation has been shown to affect growth and development of the embryo, but an effect on imprinted genes has not been shown in postimplantation embryos. In the present study, we examined the effect of superovulation/in vivo development or superovulation/3.5dpc (days post-coitum) embryo transfer on the allelic expression of Snrpn, Kcnq1ot1 and H19 in embryos and placentas at 9.5 days of gestation. Superovulation followed by in vivo development resulted in biallelic expression of Snrpn and H19 in 9.5dpc placentas while Kcnq1ot1 was not affected; in the embryos, there was normal monoallelic expression of the three imprinted genes. We did not observe significant DNA methylation perturbations in the differentially methylated regions of Snrpn or H19. Superovulation followed by embryo transfer at 3.5dpc resulted in biallelic expression of H19 in the placenta. The expression of an important growth factor closely linked to H19, Insulin-like growth factor-II, was increased in the placenta following superovulation with or without embryo transfer. These results show that both maternally and paternally methylated imprinted genes were affected, suggesting that superovulation compromises oocyte quality and interferes with the maintenance of imprinting during preimplantation development. Our findings contribute to the evidence that mechanisms for maintaining imprinting are less robust in trophectoderm-derived tissues, and have clinical implications for the screening of patients following assisted reproduction.     

Three-dimensional velocity mapping of lung motion using vessel bifurcation pattern matching

We present a new quantification technique for three-dimensional (3D) lung motion by means of tracking the anatomical features inside the lung using a set of sequential 3D-CT images (a 4D-CT image). The method is based on the conservation of topology, such as connections and junctions of vessels, during the motion. Lung CT images are used to do lung volume modeling, lung vessel extracting and thinning, and coordinates of vessel bifurcations are derived as feature points. Such feature points are tracked in a series of 3D-CT images, i.e., the points are individually tracked between two successive 3D-CT images, in which the lung is deformed. Consequently, 3D displacement vectors are obtained. The feature point tracking is carried out using point pattern matching with a probabilistic relaxation method. We examined this technique using a lung 3D-CT image and artificially deformed one, and separately scanned CT images for a rigid bifurcation phantom. The studies estimated that the error of the vectors is within approximately 1 voxel, i.e., 1 mm or less. Therefore, the accuracy is expected to be high enough for radiation therapy. This technique enables us to quantify realistic 3D organ motion without any fiducial markers. It can be applied to the quantification of tumor (target volume) deformation by gridding interpolation into all voxels. We expect it to be useful for dose estimation in mobile organs and for 4D treatment planning in radiation therapy.     

Phenotype of triploid embryos

The phenotypes of triploid fetuses and placentae are now well established and known to correlate with parental origin of the extra haploid set of chromosomes. In fetuses, it is not clear whether there is a direct parent of origin effect on the fetus itself or if the phenotypes are the result of growth differences influenced by abnormalities in growth and function of the placenta. Examining the phenotype of triploid embryos at an earlier stage in gestation, when the placenta effects may be less pronounced, could help clarify this question. A phenotype characteristic of triploidy in the embryonic period has been described; however, parental origin was not determined in these embryonic cases. In the present study, a population of triploid embryos is assessed to determine if there is a correlation between parental origin and phenotype. Parental origin was determined in 27 first trimester miscarriages. Digyny accounted for 19 cases and diandry for eight cases. Assessment of embryonic phenotype with parental origin showed no correlation between the phenotype of the embryo and parental origin of the extra haploid set. While there may be subtle effects of imprinting on embryonic development, they are not as obvious as they are in the mouse, consistent with the general trend of fewer imprinted genes in human beings compared with the mouse.     

Biomaterial mesh seeded with vascular remnants from a quail embryo has a significant and fast vascular templating effect on host implant tissue

Seeding biomaterial implants with vascular remnants has the potential to facilitate host vessel ingrowth via a vascular templating effect. Vessels from quail embryo were grown into a polyurethane fibroporous mesh and the samples were frozen-thawed and then implanted in rat subcutaneous dorsum. Results show that the process of revascularization, using the quail vessel remnants, occurred over the first 3 days after implantation and resulted in functional vessels. Rat endothelial cells were found in the quail templates on day 1. On day 2 the endothelial cells formed a confluent layer and started producing laminin. By this time approximately 70% of the rat vessel tissue in the implant had grown into quail vascular remnants, indicating that the quail vessels were extensively used as templates for host vessel ingrowth. Laminin production was increased and collagen production started by day 3, at which time the vessels were functional in that rat blood flowed through them. At 2 weeks host vessel density was approximately twice that of control samples; thus the implant substantially enhanced the size of the vascular network. For meshes that additionally received vascular endothelial growth factor (VEGF) seeding before implantation, vessel density at 2 weeks was enhanced over samples with quail embryo alone. However, the quail was found to have the greatest angiogenic effect above any of the implant components-quail, VEGF, and collagen. Tissue engineering of vessel templates may thus be a realistic solution to effective fast vascularization of biomaterials.     

Multiview Robotic Microscope Reveals the In-plane Kinematics of Amphibian Neurulation

A new robotic microscope system, called the Frogatron 3000, was developed to collect time-lapse images from arbitrary viewing angles over the surface of live embryos. Embryos are mounted at the center of a horizontal, fluid-filled, cylindrical glass chamber around which a camera with special optics traverses. To hold them at the center of the chamber and revolve them about a vertical axis, the embryos are placed on the end of a small vertical glass tube that is rotated under computer control. To demonstrate operation of the system, it was used to capture time-lapse images of developing axolotl (amphibian) embryos from 63 viewing angles during the process of neurulation and the in-plane kinematics of the epithelia visible at the center of each view was calculated. The motions of points on the surface of the embryo were determined by digital tracking of their natural surface texture, and a least-squares algorithm was developed to calculate the deformation-rate tensor from the motions of these surface points. Principal strain rates and directions were extracted from this tensor using decomposition and eigenvector techniques. The highest observed principal true strain rate was 28± 5% per hour, along the midline of the neural plate during developmental stage 14, while the greatest contractile true strain rate was −35± 5% per hour, normal to the embryo midline during stage 15.     

Preeclampsia Is Associated with Widespread Apoptosis of Placental Cytotrophoblasts within the Uterine Wall

Preeclampsia is a serious pregnancy complication diagnosed by signs of widespread maternal endothelial dysfunction. In normal pregnancy, a subpopulation of placental cytotrophoblast stem cells executes an unusual differentiation program that leads to invasion of the uterus and its vasculature. This process attaches the conceptus to the uterine wall and starts the flow of maternal blood to the placenta. Preeclampsia is associated with abnormal cytotrophoblast differentiation, shallow invasion, and decreased blood flow to the placenta. To determine whether abnormal differentiation and/or hypoxia leads to cytotrophoblast apoptosis, we used the TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) method to label DNA strand breaks in tissue sections of the placenta and the uterine wall to which it attaches. Control samples (n = 9) showed almost no apoptosis, but in samples from patients with preeclampsia, 15-50% of the cytotrophoblasts that invaded the uterine wall were labeled (8/9 samples). These same cells failed to stain for Bcl-2, a survival factor normally expressed by trophoblasts in both the placenta and the uterine wall. Our results show that preeclampsia is associated with widespread apoptosis of cytotrophoblasts that invade the uterus. The magnitude of programmed cell death in this population may account for the sudden onset of symptoms in some patients, as well as the associated coagulopathies.     

Invasive cytotrophoblast apoptosis in pre-eclampsia

Pre-eclampsia is a serious pregnancy complication diagnosed by signs of widespread maternal endothelial dysfunction. In normal pregnancy, a subpopulation of placental cytotrophoblast stem cells executes a differentiation programme that leads to invasion of the uterus and its vasculature. This process attaches the conceptus to the uterine wall and starts the flow of maternal blood to the placenta. In pre-eclampsia, cytotrophoblasts fail to differentiate along the invasive pathway. The functional consequences of this abnormality negatively affect interstitial and endovascular invasion, thereby compromising blood flow to the maternal-fetal interface. To determine whether abnormal differentiation and/or hypoxia leads to apoptosis of invasive cytotrophoblasts, we used the TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling) method to label DNA strand breaks in tissue sections of the placenta and the uterine wall to which it attaches. Control samples (n = 9) showed little or no apoptosis in any location, but in samples from patients with pre-eclampsia, 15-50% of the cytotrophoblast subpopulation that invaded the uterine wall was labelled (8/9 samples). These same cells failed to stain for Bcl-2, a survival factor normally expressed by trophoblasts in both the placenta and the uterine wall. Our results show that pre-eclampsia is associated with widespread apoptosis of cytotrophoblasts that invade the uterus. The magnitude of programmed cell death in this population may account for the sudden onset of symptoms in some patients, as well as the associated coagulopathies.     

Hyperelastic Mechanical Properties of <Emphasis Type="Italic">Ex Vivo</Emphasis> Normal and Intrauterine Growth Restricted Placenta

Intrauterine Growth Restriction (IUGR) is a serious and prevalent pregnancy complication that is due to placental insufficiency and IUGR babies suffer significantly higher risks of mortality and morbidity. Current detection rate for IUGR is generally poor and thus an alternative diagnostic tool is needed to improve the IUGR detection. Elastography, a non-invasive method that measures the tissue stiffness, has been proposed as one such technique. However, to date, we have limited information on the mechanical properties of IUGR placenta. In this study, we investigated the mechanical properties of normal and IUGR placentae and prescribed a suitable hyperelastic model to describe their mechanical behaviors. A total of 46 normal and 43 IUGR placenta samples were investigated. Results showed that placenta samples were isotropic, but had a high spatial variability of stiffness. The samples also had significant viscoelasticity. IUGR placenta was observed to be slightly stiffer than normal placenta but the difference was significant only at compression rate of 0.25 Hz and with 20% compression depth. Three simple hyperelastic models—Yeoh, Ogden and Fung models, were found to be able to fit the experimentally measured mechanical behaviors, and Fung model performed slightly better. These results may be useful for optimizing placenta elastography for the detection of IUGR.