Quantitative three-dimensional power Doppler sonography for assessment of the fetal renal blood flow in normal gestation

Renal blood flow is very important to fetal hemodynamics. To assess the development of fetal renal vascularization and blood flow in normal gestation, we measured the fetal renal vascularization and blood flow in healthy fetuses using three-dimensional (3-D) power Doppler sonography and quantitative 3-D power Doppler histogram analysis. This study was undertaken with a prospective, cross-sectional design. In total, 106 healthy singletons with gestational ages between 20 and 40 weeks were included. The 3-D power Doppler sonography and quantitative histogram analyses were used to assess the fetal renal vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) in each case. Our results showed that all the VI, FI and VFI increased significantly with gestational age (GA). Using GA as the independent variable, the linear regression equations for fetal renal VI, FI and VFI were VI = 0.214 x GA - 3.5289 (r = 0.84, n = 106, p < 0.0001); FI = 0.3326 x GA + 35.224 (r = 0.33, n = 106, p < 0.001); and VFI = 0.1047 x GA - 1.8064 (r = 0.82, n = 106, p < 0.0001). Our study indicates that normal fetal renal vasculature and blood flow increase with the advancement of gestational age. In addition to our previous study for fetal renal volume using 3-D sonography, our data in this series may serve as a reference for further studies of fetal renal blood flow in abnormal conditions.     

羊水过多胎儿血流变化的临床研究

目的探讨羊水过多胎儿血流的变化。方法对１３例足月妊娠羊水过多应用彩色多普勒显像技术（ＣＤＦＩ）检测胎儿肾动脉,大脑中动脉的搏动指数（ＰＩ）、阻力指数（ＲＩ）以及脐动脉Ｓ／Ｄ。结果羊水过多胎儿肾动脉ＰＩ、ＲＩ明显高于正常羊水量对照组（Ｐ＜０．０５）;大脑中动脉ＰＩ、ＲＩ,脐动脉Ｓ／Ｄ值两组比较无显差异（Ｐ＞０．０５）。结论羊水过多与胎儿肾动脉血流有明显相关性,其胎儿肾动脉血流阻力改变在羊水过多中的     

彩色多普勒超声监测妊高征胎儿主要血管血流动力学变化

应用彩色多普勒超声对30例正常足月孕妇及30例妊高征孕妇的胎儿进行全面监测脐带动脉、主动脉、肾动脉及大脑中动脉血流动力学变化.结果发现:脐动脉、脑动脉、肾动脉及主动脉血流动力学参数变化是一致的,有显著相关性.当胎儿宫内缺氧时,脐动脉、肾动脉及主动脉血流速度降低,阻力增加,脑动脉血流速度增加,阻力降低.结果表明:彩色多普勒超声全面评价胎儿重要靶器官的血流动力学参数,能更敏感准确地反映高危妊娠胎儿血流动力学改变,是有价值的胎儿监测手段.     

The time-distance recorder as a means of improving the accuracy of fetal blood flow measurements

The influence of pulsatile diameter changes on calculation of volume flow has been studied. In vitro studies and an animal study were carried out with a real-time imaging and pulsed Doppler velocity measurement system. For precise pulsatile diameter information a wall motion tracking device was incorporated. Whereas in vitro a high degree of accuracy was found for the measurements of volume flow, this could not be substantiated in the descending aorta of the fetal lamb, in which Doppler volume flow differed between -7.5 and 17% from magnetic volume flow. In a clinical study the relative influence of various diameter approximations on calculated fetal aortic volume flow was assessed in 16 normal third trimester pregnancies. Depending on the selected diameter approximation method it appeared that differences from 19% underestimation to 9% overestimation in calculated volume flow could be obtained when reference was made to volume flow derived from diameter and velocity information.     

Perinatal pseudocoarctation: echocardiographic findings in vein of Galen malformation.

OBJECTIVE: Vein of Galen aneurysmal malformations (VGAMs) are rare congenital malformations thought to develop during weeks 6 to 11 of fetal life. Although they represent less than 1% of all cerebral vascular malformations, they constitute up to 30% of all pediatric vascular malformations. Vein of Galen aneurysmal malformations cause high-output heart failure in the fetus and neonate secondary to the decreased resistance and high blood flow in the lesion. We describe 2 cases, 1 prenatal and 1 postnatal, in which unusual aortic Doppler flow patterns and substantial brachiocephalic vessel dilation contributed to the discovery of a VGAM. METHODS: Echocardiographic findings associated with VGAM malformations in 2 cases are described. RESULTS: Unusual Doppler flow patterns and substantial brachiocephalic vessel dilation were seen in both cases. Pseudocoarctation of the aorta was also noted in both cases. CONCLUSIONS: The echocardiographic findings in fetal and neonatal VGAM may include pseudocoarctation of the aorta. Abnormal fetal cardiac findings should raise the practitioner's suspicion for cerebral malformations and vice versa.     

正常中孕胎儿大脑中动脉血流参数比值的正常值范围

目的 确定正常中孕胎儿大脑中动脉血流参比值的正常值范围。方法 应用二维超声、彩色多普勒能量图及脉冲多普勒技术对215例16-31孕周正常胎儿头围、体重及大脑中动脉血流参数进行检测。结果 正常中孕胎儿每分钟单位体重大脑中动脉的最大速度及平均速度随孕周的增加而降低;每分单位头围大脑中动脉的最大速度及平均速度在中孕期间变化小。结论 本研究为多普勒超声早期预测胎儿高动力循环状态提供了理论依据。     

Intrauterine growth restriction and Doppler ultrasonography.

To clarify the difference between the fetus that is small for gestational age and the fetus with true intrauterine growth restriction, we undertook a retrospective study of singleton fetuses who had fetal weight estimation and umbilical artery Doppler velocity studies within 2 weeks of their delivery. Fetuses were divided into four categories on the basis of sonographic results from their last examination. Statistical comparisons of neonatal outcome were made for the four groups, which totaled 578 fetuses. Increased cesarean section for fetal distress, stays in the neonatal intensive care unit, and increased neonatal morbidity were seen in both small for gestational age and average for gestational age neonates with abnormal Doppler blood flow. The small for gestational age fetuses with normal Doppler studies showed no increased morbidity when compared with their average for gestational age cohorts. Umbilical artery Doppler blood flow studies were a better predictor of neonatal outcome than estimated fetal weight. Small for gestational age fetuses with normal Doppler studies most likely represent constitutionally small, not pathologically growth restricted, fetuses.     

应用PDE检测正常胎儿心脏各瓣口血流速度

本研究应用脉冲多普勒超声心动图（PDE）检测正常胎儿心脏各瓣口峰值血流速度。将100例胎儿按孕周20～40周分为五组。PDE检测结果表明：胎儿心脏动脉瓣口血流呈单峰频谱，房室瓣口血流呈双峰频谱（E峰、A峰）；各瓣口峰值血流速度随孕周而增加，与孕周呈正相关，有统计学意义（P＜0．05）。PDE对于检测胎儿心脏血流，评价胎儿心脏功能具有重要作用。     

Normal cardiac flow velocities at 14-16 weeks of gestation measured by transvaginal ultrasound.

OBJECTIVE: Doppler ultrasound has been used to study the flow velocities through the valves and arteries of the fetal heart. Using transvaginal sonography, we sought to determine normal values for flow velocities through the fetal heart valves at 14-16 weeks of gestation. METHODS: Eighty-seven normal fetuses were examined. The flow velocity waveforms were visualized using Doppler ultrasound with the sample volume calipers placed just distally to the four fetal valves. Peak E- and A-wave velocities were recorded for the tricuspid and mitral valves and peak systolic flow velocities were recorded for the ascending aorta and pulmonary arteries. Linear regression for comparison of flow velocities with gestational age was performed. RESULTS: There was no significant correlation between any of the velocities and gestational age. CONCLUSIONS: Flow velocities through the fetal cardiac valves remain unchanged at 14-16 weeks of gestation as measured by transvaginal Doppler sonography.     

The value of color Doppler sonography in the diagnosis of renal agenesis.

Real-time ultrasonographic diagnosis of renal agenesis may be difficult because of severe oligohydramnios. Recent reports have suggested that the absence of renal arteries on color Doppler ultrasonography may assist in the identification of renal agenesis. Because the position of the renal arteries is variable owing to fetal size, this study was undertaken to determine the location of the renal arteries as a function of fetal growth. Using color Doppler ultrasonography, 200 normal fetuses were studied in which the length of the aortic segment from the bifurcation of the iliac arteries to the renal arteries was measured. Regression analysis was performed in which the measured aortic segment was the dependent variable and the femur length the independent variable. Four cases of severe oligohydramnios were studied. The regression equation for the length of the aortic segment (Y) was significantly (P < 0.000001; R = 0.921) related to the femur length (X) (Yaortic segment (mm) = 3.1950 + 0.3034Xfemur length (mm); 99% prediction interval +/- 4.6 mm). In three cases of renal agenesis the renal arteries were not imaged with color Doppler sonography. Color Doppler imaging may be useful to identify the location of the renal arteries as they originate from the aorta. Using the data from this study, the location of the renal arteries can be determined for the corresponding femur length. If the renal arteries are not identified within the expected range (+/- 99% prediction interval) in fetuses in whom the kidneys are not identified with real-time ultrasonography, renal agenesis must be considered.     

Three-dimensional power Doppler ultrasound for the assessment of the fetal brain blood flow in normal gestation

Early identification of the abnormal fetal brain vascularization and blood flow is very important, because the deficient perfusion of the fetal brain may be related to a poor prognosis of the central nervous system (CNS) development. To assess the fetal brain vascularization and the blood flow in normal gestation, we measured the fetal brain vascularization and the brain blood flow in normal fetuses using three-dimensional (3-D) power Doppler ultrasound (US) and the quantitative 3-D power Doppler histogram analysis. This study was undertaken by a prospective and cross-sectional design. In total, 155 normal singletons with gestational age (GA) between 21 and 40 weeks were included. The 3-D power Doppler US and the quantitative 3-D histogram analyses were used to assess the fetal brain vascular indexes, i.e., vascularization index (VI), flow index (FI) and vascularization-flow index (VFI), in each case. Our results revealed that all the fetal brain VI, FI and VFI increased significantly with GA (all p<0.001). In addition, the fetal brain VI, FI and VFI were all significantly correlated with the common fetal growth indices, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight. Our study indicates that fetal brain vascularization and blood flow increase significantly with the advancement of GA as well as the fetal common growth indices during normal gestation. We believe our data may serve as a reference for further studies of the fetal brain blood flow in abnormal conditions.     

彩色多普勒血流动力学指标预测胎儿缺氧及酸中毒的价值

目的： 评价血液动力学指标预测胎儿缺氧及酸中毒的价值。方法： 用彩色多普勒超声检测 ５４ 例正常晚 期妊娠 （正常组） 和 ３６ 例高危妊娠 （高危组） 妇女子宫动脉 （ＵｔＡ） 和胎儿脐动脉 （Ｕｍ Ａ）、大脑中动脉（Ｍ ＣＡ）、肾动脉 （ＲＡ） 的血流速度波型 （ＦＶＷ ｓ）, 并且测定高危组脐动脉血气。结果： 高危组ＵｔＡ、Ｕｍ Ａ、ＲＡ 的阻力指数 （ＲＩ） 搏动指数 （ＰＩ） 及收缩期最大血流速度与舒张末期血流速度的比值 （Ｓ／Ｄ） 均高于正常组, 而Ｍ ＣＡ的ＰＩ及Ｓ／Ｄ 值均明显低于正常组 （Ｐ＜ ００５）。与Ｕｍ Ａ 氧分压 （ＰＯ２） ＞ ２５ｋＰａ 的高危妊娠病例比较, Ｕｍ Ａ ＰＯ２＜２５ ｋＰａ 者ＵｔＡ 的Ｓ／Ｄ 值, Ｕｍ Ａ 的ＰＩ, Ｓ／Ｄ 值以及ＲＡ 的ＲＩ、ＰＩ、Ｓ／Ｄ 值均明显增高, Ｍ ＣＡ 的ＰＩ明显降低 （Ｐ＜００５）。Ｕｍ Ａ 及ＲＡ 的ＰＩ与Ｕｍ Ａ ＰＯ２ 的ｐＨ 值呈负相关, 与二氧化碳分压 （ＰＣＯ２） 呈正相关, Ｍ ＣＡ 的ＰＩ与Ｕｍ Ａ的 ｐＨ、ＰＯ２ 呈正相关, 与ＰＣＯ２ 呈负相关。结论： 高危妊娠胎儿缺氧时, Ｍ ＣＡ 血流阻力降低, 而周围血管, 特别是肾血管血流阻力明显升高。胎儿血液动力学变化与缺氧及酸碱平衡失     

Fetal arterial and venous Doppler parameters in the interpretation of oligohydramnios in postterm pregnancies.

OBJECTIVE: The objective of the current study was to evaluate fetal arterial and venous Doppler parameters in postterm pregnancies with oligohydramnios and those with normal amniotic fluid. STUDY DESIGN: A cross-sectional study was performed in 38 pregnancies beyond 41 weeks' gestation. Pulsed Doppler imaging was used to determine the pulsatility index (PI) for the fetal middle cerebral artery (MCA), renal artery, umbilical artery, inferior vena cava (IVC) and ductus venosus. The amniotic fluid index (AFI) was used for semiquantitive assessment of amniotic fluid volume. Oligohydramnios was defined as an AFI < 5 cm. RESULTS: Oligohydramnios was detected in 10 cases, and a normal AFI was present in 28 cases. In the presence of oligohydramnios the PI of the MCA was decreased, while the renal artery PI and the MCA PI/UA PI ratio were found to be elevated. In cases of oligohydramnios the PI in the IVC was increased but was unchanged in the ductus venosus. CONCLUSION: Oligohydramnios in post-term pregnancies is associated with arterial redistribution of fetal blood flow typifying the brain sparing effect and with decreased resistance in the MCA and increased resistance in the fetal IVC.     

超声观察正常胎儿肾动脉的血流动力学参数及其临床价值

目的以彩色多普勒超声观察不同孕周胎儿肾动脉(RA)收缩期峰值血流速度(Vmax)、舒张期最低血流速度(Vmin)及搏动指数(PI)、阻力指数(RI),确定其正常参考值,分析其与孕龄的相关性。方法从接受常规产前超声检查的18～40周孕妇中选取符合条件的2627名进入样本库,测量胎儿肾动脉Vmax、Vmin和PI、RI,最后按孕龄分组,并进行统计学处理。结果胎儿左、右侧肾动脉血流Vmax(r=0.75,0.75)、Vmin(r=0.62,0.60)与孕龄呈正相关(P均<0.05),RI、PI随孕龄增长而呈缓慢下降趋势,仅在妊娠末期略有回升;胎儿左、右肾各血流参数测值间差异无统计学意义(P>0.05)。结论胎儿肾动脉血流速度与孕龄呈正相关,而肾动脉RI、PI随孕龄变化幅度很小。胎儿肾动脉血流监测可作为预测和评估胎儿有无宫内缺氧的方法之一。     

彩色多普勒超声对宫内发育迟缓胎儿动静脉的血流动力学研究

目的应用彩色多普勒超声检测宫内发育迟缓(IUGR)胎儿动静脉的血流动力学参数。方法测量胎儿静脉导管和脐静脉的血流量,计算静脉导管(DV)分流率;测量胎儿脐动脉、大脑中动脉(MCA)、肾动脉的搏动指数(PI)、阻力指数(RI)及脐动脉收缩期最大流速与舒张末期流速的比值(S/D),结果进行对比分析。结果与对照组比较,IUGR组胎儿脐动脉的PI、RI、S/D及肾动脉的RI显著增高,MCA的PI、RI及S/D显著减低,DV分流率显著增加,差异均有统计学意义(P<0.05)。结论彩色多普勒超声通过综合监测胎儿血流动力学变化,可以全面、客观地评价胎儿的供血情况,预测胎儿宫内缺氧和IUCR情况。     

彩色多普勒超声对多囊肾患者肾脏血流的研究

目的　为了探讨常染色体显性多囊肾病 (autosomal dominantpolycystic kidney disease,ADPKD)对患者肾脏血流的影响 ,采用彩色多普勒超声测定血管的平均峰值流速 (Vmax、 Vmin)、阻力指数 (RI) ,确定肾脏血流与肾功能的关系以及囊肿大小与肾脏血流的关系。方法　选取 4 2例 ADPKD患者 ,以 4 5例正常人作为对照组。彩色多普勒超声测定双侧肾动脉 ,囊肿周边叶间动脉的最大、最小峰值流速和阻力指数。常规测定受试者的血清肌酐、尿素氮以及肌酐清除率。结果　 (1)多囊肾病组 (包括肾功能正常和异常组 )肾动脉平均峰值流速低于正常对照组 ,两者相比有明显差异 (P<0 .0 1) ;(2 )肾功能正常的多囊肾病组 RI较正常对照组升高 ,且具有统计学意义 (P<0 .0 5 ) ;(3)肾功能异常的多囊肾病组 RI较正常对照组升高 ,两者相比有明显差异 (P<0 .0 1) ;(4) RI与患者的肾功能呈正相关。结论　彩色多普勒超声检测能提示 ADPKD患者的肾脏血流情况 ,较肾功能测定更为敏感 ,为临床评价肾血流状态及疾病的转归、疗效的判定提供了一种新方法。     

双功彩色多普勒显像对Ⅱ型糖尿病患者肾动脉血流的研究

本文检测３０例正常人，６６例Ⅱ型糖尿病患者的肾动脉主于和段间动脉的血流频谱。结果表明：第一组肾主动脉血流频谱各项参数与正常对照组比较，均未见统计学差异。段间动脉的ＲＩ与对照组比较有显著性差异，（Ｐ＜０．０１）。第二组肾动脉和段间动脉的血流动力学参数与对照组比较有显著性差异。第二组处于收缩期正常流速，舒张末期低流速，肾血管高阻状态。我们认为根据多普勒定量参数（Ｖｄｍｉｎ、ＰＩ、ＲＩ），特殊的频谱图形和彩流图改变，可对肾血管受损作出判断。     

Ultrasonic measurement of fetal blood velocity wave form as a secondary diagnostic test in screening for intrauterine growth retardation

Based on routine fetometry screening at 32 weeks of gestation, 80 out of 3226 singleton pregnancies were suspected of intrauterine growth retardation (IUGR) and 72 of them were subjected to repeated fetal blood flow measurements by Doppler ultrasound for evaluation of the fetal condition. The maximum blood velocity wave form recorded from the fetal descending aorta and umbilical artery was classified as normal or abnormal depending on the presence or absence of positive end-diastolic blood flow. Compared to the pregnancies with normal fetal blood flow, the group of 30 pregnancies with abnormal blood flow patterns had significantly more pregnancy complications and more operative deliveries for fetal distress. In the latter group, all newborns but one were small-for-gestational age and had low 1-min Apgar scores more frequently. Fetal blood flow measurements have a good capacity for predicting unfavorable fetal outcomes and can be recommended for clinical use. The combination of ultrasound screening and Doppler blood flow measurement has reduced the number of pregnancies requiring intensive surveillance.     

Assessment of normal fetal liver blood flow using quantitative three-dimensional power Doppler ultrasound

Fetal liver blood flow is very important for fetal hemodynamics. To assess the development of fetal liver vascularization and blood flow in normal gestation, we measured the fetal liver vascularization and blood flow in normal fetuses using the three-dimensional (3-D) power Doppler ultrasound (US) and quantitative 3-D power Doppler histogram analysis. This study was undertaken with a prospective, cross-sectional design. In total, 196 normal singletons with gestational age between 20 and 40 weeks were included. The 3-D power Doppler US and the quantitative histogram analysis were used to assess the fetal liver vascularization index (VI), flow index (FI), vascularization-flow index (VFI) and mean greyness in each case. Our results showed that all the fetal liver VI, FI and VFI increased significantly with gestational age (GA), whereas, fetal liver mean greyness decreased with GA. Using GA as the independent variable, the linear regression equations for fetal liver VI, FI, VFI and mean greyness were VI = 0.5746 x GA - 5.8264 (r = 0.86, p < 0.0001), FI = 0.3291 x GA + 35.624 (r = 0.35, p < 0.001), VFI = 0.2905 x GA - 3.4871 (r = 0.82, p < 0.0001) and mean greyness = -0.2034 x GA + 42.315 (r = -0.20, p < 0.0001). In addition, fetal liver VI, FI, VFI and nean greyness were all significantly correlated with common fetal growth indexes, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight. Our study indicates that normal fetal liver vascularization and blood flow change significantly with the advancement of GA as well as fetal growth indexes. We believe our data may serve as a reference for further studies of fetal liver blood flow in abnormal conditions.     

胎儿冠状动脉瘘的超声心动图评价

目的通过回顾性分析胎儿冠状动脉瘘的超声图像特征,探讨超声心动图在胎儿冠状动脉瘘诊断中的价值。 方法选取2016年1月至2017年12月在武汉协和医院行产前超声心动图检查诊断为冠状动脉瘘的胎儿9例,对其二维超声图像、彩色多普勒图像、血流频谱特征及其合并畸形情况进行分析,其中5例与出生后超声诊断结果或引产后尸检结果进行对照。 结果产前超声心动图诊断为冠状动脉瘘的9例胎儿,均可观察到受累冠状动脉扩张,彩色多普勒血流成像（CDFI）可显示冠状动脉瘘管的起源、走行、内径、血流情况及瘘入部位,频谱多普勒可探及瘘管内特征性血流频谱。9例胎儿中,2例出生后经超声心动图检查确诊为冠状动脉瘘,3例引产后尸检证实为冠状动脉瘘,4例引产后未行尸检。 结论胎儿冠状动脉瘘的超声心动图具有特征性改变,产前正确诊断胎儿冠状动脉瘘对评估胎儿预后及早期治疗有重要意义。