Sonography of normal fetal bowel

This is a prospective study of the sonographic appearance of normal small bowel and colon in 300 fetuses. Normal fetal bowel can be frequently seen during sonographic examination. The diameter of the lumen of the small bowel and colon increases as gestational age increases. The fetal small bowel lumen rarely exceeds 6 mm in diameter, and fetal colon lumen diameter rarely exceeds 23 mm. Small bowel peristalsis can be seen with increasing frequency with increasing gestational age. Colon peristalsis is not seen. Haustral folds in the colon can be frequently demonstrated. Meconium in the colon always remains hypoechoic relative to the fetal liver and bowel wall. Hyperechoic appearance of the small bowel in early gestation and cystic appearance of parts of the colon in later gestation may mimic pathology. Normal herniation of bowel into umbilical cord can be seen in early (8 to 11 weeks) gestation.     

胎儿超声心动图检查定量11~17周正常胎儿主动脉和肺动脉内径Z-评分的初步研究

目的探讨早孕期（11^＋0周~13^＋6周）和中孕早期（14^＋0周~17^＋6周）胎儿主动脉内径（AO）与肺动脉内径（PA）与胎儿生物学生长参数的相关性,初步建立早孕期和中孕早期胎儿AO与PA的正常参考值范围及Z-评分方程,并评价方程的有效性。 方法随机选取孕周（GA）为（11^＋0周~17^＋6周）正常单胎胎儿270例,将成功显示左、右心室流出道切面的245例胎儿纳入研究,获得胎儿顶臀径（CRL）、双顶径（BPD）、股骨长径（FL）、孕周（GA）等生物学生长参数。在胎儿左、右心室流出道切面测量收缩末期AO及PA,以GA、BPD和FL作为独立自变量,AO及PA作为因变量,建立AO、PA的正常参考值范围,并对每个参数的绝对残差（SD）进行加权回归,建立Z-评分方程。 结果采用简单的线性回归模型,可以很好地描述AO和PA与非心脏生物特征参数（BPD、FL、GA）的关系。AO、PA与GA、BPD、FL均呈显著线性相关（GA与AO：r=0.9276,GA与PA：r=0.9271,BPD与AO：r=0.9551,BPD与PA：r=0.9558,FL与AO：r=0.9462,FL与PA：r=0.9483,均<0.001）,其中与BPD的相关性最强。 结论正常早孕期及中孕早期胎儿的AO、PA随着孕周的增加而增长,本研究初步建立了正常胎儿早孕期及中孕早期AO、PA的参考范围及其Z-评分方程。为早孕期及中孕早期评估胎儿大血管生长提供精确的参考标准,在早期筛查或诊断胎儿先天性心脏畸形方面具有潜在的应用价值。     

Fetal bowel. Normal sonographic findings

The normal sonographic appearance of fetal colon and small bowel is reported in a prospective study of 130 fetuses. The colon, which appeared as a continuous tubular structure located around the perimeter of the abdominal cavity, was seen in some fetuses as early as 22 menstrual weeks and in all fetuses examined after 28 weeks. Colon diameter demonstrated a linear relation (r = 0.82) with menstrual age, reaching a maximum of 18 mm at term. In comparison, small bowel was located centrally and individual segments never exceeded 7 mm in diameter or 15 mm in length. Small bowel loops were seen in only 30% of fetuses examined after 34 weeks. Peristalsis was routinely demonstrated of the small bowel, but was not observed in the colon.     

Congenital short-bowel syndrome: Prenatal sonographic findings of a fatal anomaly

The sonographic findings in a fatal case of congenital short-bowel syndrome are reported. Sonography at 11 weeks of gestation showed a 11 × 6 mm hyperechoic mass interpreted to be a midgut umbilical hernia. A repeat scan 2 weeks later showed an intact anterior abdominal wall, no umbilical herniation, and appropriate fetal growth. Forty-eight hours after full-term, vaginal delivery, the infant began vomiting bile and passing blood rectally. Imaging studies showed distended bowel loops without air-fluid levels and incomplete bowel obstruction. Laparotomy showed malrotation and short small bowel without volvulus. The infant died at 9 weeks of age. When delayed return of the midgut to the abdominal cavity is noted on prenatal sonograms, follow-up sonograms should be done throughout the second trimester, especially in patients with a family history of short-bowel syndrome, to search for dilated short bowel loops. If such loops are found, patients should be given options for pregnancy termination. © 1998 John Wiley & Sons, Inc. J Clin Ultrasound 26 : 106–108, 1998.     

Sonographic appearance of occipital fetal hair

The sonographic characteristics and the frequency of the presence or absence of fetal hair in the occipital region was determined from 16 weeks to 42 weeks of menstrual age. Our results suggest that the ultrasonic appearance of occipital hair is first noted at approximately 24 weeks of menstrual age and there is a progressive increase in frequency of hair presence as pregnancy approaches term. The normal ultrasonic characteristics of occipital fetal hair are described, and the differential diagnoses between normal fetal hair and malformations such as meningocele, encephaloceles, or cystic hygromas is discussed.     

Prediction of normal fetal growth by the Rossavik growth model using two scans before 27 weeks, menstrual age

Individual growth curve standards for five fetal anatomic parameters (head and abdominal circumferences, head and abdominal cubes, and femur diaphysis length) and estimated fetal weight were prospectively developed in 70 pregnant women who delivered infants with growth considered appropriate-for-menstrual age. For this purpose, we used the Rossavik growth model (P = c(t) kappa + s(t], model specification functions previously reported, and the data of two scans before 27.0 weeks of menstrual age, separated by an interval of at least 5 weeks. The anatomic parameters and estimated weights of these fetuses in the last 14 weeks of gestation were found to have values close to their projected standards. Whereas there was a significant, although small, systematic error of overprediction for most of the parameters and estimated fetal weight, deviations between observed and expected values were, with few exceptions, within the ranges established by Deter for normal growth. This study demonstrates that the Rossavik growth model could be used to predict normal fetal growth in a sample of patients different from those from which the model was developed.     

四腔心平面头侧偏斜法快速筛查胎儿先天性心脏畸形

目的探讨四腔心平面头侧偏斜法在诊断胎儿心脏畸形中的价值。方法应用彩色多普勒超声仪对在我院产前检查的妊娠18～40周连续病例15608例，进行胎儿心脏四腔心平面头侧偏斜法检测，即横切胎儿胸腔获取四腔心切面，观察心房与心室及其连接关系、房室间隔、左右房室瓣以及肺静脉与左房的连接关系，然后将探头声束平面略向胎儿头侧偏斜，依次显示左心室与主动脉的连接关系及右心室与肺动脉的连接关系，且实时动态扫查时观察主、肺动脉起始部的交叉及主、肺动脉相对大小，从而对心脏的主要结构及连接关系作出快速评价。结果15608例胎儿中，经产后或引产证实的各种心脏畸形126例，四腔心平面头侧偏斜法检出各种心脏畸形117例，漏诊9例。结论四腔心平面头侧偏斜法是显示胎儿心脏结构及产前筛查胎儿心脏畸形的重要影像诊断方法。     

胎儿肠梗阻的MRI诊断

目的观察胎儿期肠梗阻MRI表现,结合生后手术史及病理学诊断,探讨MRI对胎儿期肠梗阻的诊断价值。材料与方法回顾性分析胎儿期肠梗阻病例26例,胎龄为孕23~35 w,均先行胎儿超声检查后再行胎儿MRI平扫。采用2D快速平衡稳态进动序列(2D fast imaging employ steady acquisition,2D FIESTA)、单次激发快速自旋回波(single-shot fast spin echo,SSFSE)序列、快速反转恢复运动抑制序列T1WI(fast inversion recovery motion insensitive T1WI,FIRM T1WI)和弥散加权成像(diffusion weighted imaging,DWI)序列。根据梗阻部位、梗阻区肠管信号改变、梗阻远端肠道充盈情况、肠系膜血管异常等进行影像学诊断,并观察继发改变如腹水、羊水增多等,随访出生情况及手术治疗结果,分析MRI诊断的正确率及漏诊率,探讨MRI各序列在胎儿肠梗阻诊断中的优势。结果 26例肠梗阻胎儿中:十二指肠/空肠狭窄或闭锁16例,其中4例伴十二指肠和空肠旋转不良;胎粪性小肠梗阻4例,其中2例继发肠扭转致肠缺血坏死;肛门闭锁4例;结肠狭窄或闭锁1例;先天性巨结肠1例。所有胎儿均伴有不同程度羊水增多,部分病例伴腹水、心包积液及睾丸鞘膜积液;2例为单脐动脉。MRI诊断正确率为92.3%(24/26),误诊率为7.7%(2/26)。MRI能清楚显示胎儿肠梗阻部位,观测肠管扩张的程度。SSFSE序列可显示系膜血管受累,FIRM T1WI序列有助于结肠梗阻的诊断,DWI序列可提示梗阻肠管缺血和出血的改变。结论胎儿期肠梗阻MRI图像有特征性改变,可以判断受累肠管的发生部位、梗阻程度和合并症等,对产前诊断和出生后手术治疗有重要参考价值。     

In utero ultrasound diagnosis of congenital heart disease

Two hundred and one pregnancies considered at high risk for congenital heart disease (CHD) underwent fetal cross-sectional echocardiographic (CSE) examination. In 190 cases a structurally normal heart was correctly predicted; seven cases of CHD were identified, but in two of them the specific diagnosis was inaccurate. One false positive diagnosis of a small ventricular septal defect was made. There were three false negative diagnoses: two of ventricular septal defects and one of aortic coarctation. We conclude that severe heart malformations can be reliably identified or excluded by CSE in utero, but important anatomical details may be missed. Therefore, prognosis should be based only on the structures identified to multiple-scan planes.     

Pulsed Doppler fetal echocardiography

Pulsed Doppler echocardiography (PDE) has proven value in the examination of the infant or child with known or suspected congenital heart disease. In order to assess how PDE might be useful in the evaluation of the infant in utero, we reviewed our experience with this technique used in combination with both cross-sectional and M-mode echocardiography. Where previous examinations had suggested some abnormality or where there was a risk factor for congenital heart disease, we performed PDE examinations on the cardiovascular system of 36 infants in utero ranging in gestational age from 20-39 weeks (mean 32 weeks). PDE of the fetal heart was found to be valuable in three areas: (1) quantitation of hemodynamics, (2) characterization of cardiac rhythm, and (3) identification of certain congenital cardiovascular structural anomalies.     

正常胎儿心脏肺循环血流的超声心动图特征

目的 :应用彩色多普勒超声心动图检测正常胎儿心脏肺循环血流 ,观察肺动脉及分支血流形态特点并探讨其意义。方法 :入选妊娠 2 0～ 4 1周的正常胎儿 339例。并按孕周分组 ,<2 8周为 组 ;2 8～ 36周为 组 ;>36周为 组 ;应用多普勒超声心动图观察肺动脉主干及分支血流形态 ,测量参数包括 :血流最大流速 (Vmax)、血流速度积分 (VTI)、血流加速时间 (ACT)、减速时间 (DT)及射血时间 (ET)、并计算瓣口血流量。结果 :1.正常胎儿心脏主动脉及肺动脉内径随孕周增加而增大 ,各孕周肺动脉内径均明显大于主动脉内径 ;2 .肺动脉瓣口血流速度低于主动脉瓣口血流速度 ,但肺动脉流量大于主动脉流量 ,且肺动脉流量与主动脉流量比值不随孕周而改变 ,始终保持恒定 ;3.动脉导管血流呈连续单向双期双峰血流 ,其收缩期流速始终明显高于主动脉瓣口及肺动脉瓣口流速。收缩期血流速度及收缩期与舒张期血流速度比值随孕周增加而增大 ;4 .肺动脉分支血流呈单向双峰 ,流速明显低于肺动脉瓣口流速 ,其血流形态表现为高阻力低灌注的特点。此形态孕早期即可出现 ,且不随孕龄的增加而改变。结论 :正常胎儿肺动脉循环系统的固有特点在孕早期即出现 ,并不随孕龄改变。因此早期应用彩色多普勒超声心动图检查 ,对判定胎儿心脏发育情况具     

胎儿超声心动图在胎儿先天性心脏病产前诊断中的临床价值

目的 探讨胎儿超声心动图在产前诊断胎儿先天性心脏病的临床意义。方法 选择妊娠＞16周,分娩前有高危倾向的孕妇310例行胎儿超声心动图检查。检查中着重观察胎儿腹部切面、胎儿四腔心切面、胎儿左右室流出道长轴或大动脉短轴切面、胎儿主动脉弓长轴切面。结果 共发现9例先天性心脏病胎儿,其中复杂先天性心脏病7例、单纯室间隔缺损1例、1例出生前未确诊,出生后诊断为法洛四联症。敏感性82％,特异性100％。结论 胎儿超声心动图早期诊断胎儿畸形,评价胎儿心功能的有用工具。其诊断的准确性受孕妇体形、胎儿体位以及检查者的经验积累等多方面因素的影响。     

Computer assisted analysis of fetal age in the third trimester using multiple fetal growth parameters

A new technique is described for predicting menstrual age in the third trimester of pregnancy (28-42 weeks) using multiple fetal growth parameters (biparietal diameter, head circumference, abdominal circumference, femur length). Evaluation of this technique in 177 normal third trimester pregnancies demonstrated that significant improvement in the variability in predicting menstrual age can be achieved when two or more parameters are used collectively instead of a single parameter used individually. The optimal combination prior to 36 weeks was biparietal diameter, abdominal circumference, and femur length, while after 36 weeks the optimal combination was head circumference, abdominal circumference, and femur length. The use of these combinations resulted in smaller mean errors, standard deviations, and maximum errors. Regression equations and tables of normal values are provided to facilitate the use of this dating method.     

超声测定正常胎儿心脏房室瓣环、腔室径及其与胎龄的相关性

目的建立不同孕周时超声测定胎儿心脏各腔室径的正常值,探讨心脏测值随孕周变化的规律。方法将胎龄为16～40周的552胎正常胎儿按照胎龄分为13组,应用高分辨二维超声心动图测量其房室瓣环径、二、三尖瓣距离(M-TD)及心脏各腔室径,计算正常均值,对各测定值与胎龄绘制散点图进行相关和回归分析,选择最优化方程。结果胎儿期心脏结构各测定值随胎龄增加而增大,与孕周呈显著正相关(P均<0.01);M-TD与胎龄呈线性相关,二、三尖瓣环径及其他心脏各腔室测值与胎龄之间呈非线性相关,曲线拟合显示二次多项式方程拟合度最优。结论正常胎儿心脏房室瓣环径、M-TD以及其他房室腔各测值随胎龄而增大,与孕周呈显著正相关。     

Mathematical modeling of fetal growth: V. Fetal weight changes at term

Fetal growth after 37 weeks menstrual age was investigated by comparing ultrasound estimates of fetal weight with corresponding weights of newborns. Using a weight estimation equation with minimal systematic error, evidence was found that fetuses delivered at term do not increase in weight the last two weeks before delivery. This change in fetal growth is regarded as a biological process that is needed to prepare the fetus for its life after birth. Only one of three subsets, that of estimated weights below 3000 g, showed significant weight increase after 37 weeks. This subset had, however, on average the longest scan-delivery interval. We conclude that conventional birthweight standards are influenced both by a cessation of fetal growth approximately two weeks before delivery and by an association between fetal size and the duration of gestation.     

二维超声斑点追踪成像技术评价正常妊娠胎儿心脏功能的临床研究

目的利用二维超声斑点追踪成像技术评价正常妊娠胎儿心脏功能。方法纳入我院常规产检的正常单胎妊娠孕妇50例,分别在24、32周和37周获得胎儿心尖四腔心二维图像。测量左室及右室的整体纵向应变(GLS)和收缩期应变率(GLSr)、舒张早期应变率(GLEr)、舒张晚期应变率(GLAr)。结果LVGLS、LVGLSr、RVGLEr及RVGLAr在三个不同孕周没有统计学差异,LVGLEr 32周及37周无差异,两组均与24周有统计学差异,LVGLAr随孕周增加而减低(P<0.05)。RVGLS随孕龄增加减低,三组间差异有统计学意义(P<0.05),第37周RVGLSr与24周比较呈减低。24周时LVGLEr/GLAr<1,32周及37周LVGLEr/GLAr>1,37周及32周分别与24周比较间存在统计学差异(P<0.05)。结论二维斑点追踪技术可以敏感评价胎儿心脏的功能。胎儿期心脏应变及应变率的变化反映了胎儿心脏成熟的过程,对其的研究可以更好的理解正常的生理变化。     

Transvaginal sonographic measurement of fetal kidneys in the first trimester of pregnancy

Fetal renal size late in the first trimester of pregnancy was evaluated by transvaginal ultrasonography in 50 patients not at risk for congenital kidney disease and whose pregnancies resulted in a normal outcome. Both kidneys were reliably identified in all patients scanned at 12 weeks, 13 weeks, and 14 weeks, menstrual age. Kidney diameter measurements obtained in this study are presented for reference in evaluating patients in late first trimester whose fetuses are at risk for kidney abnormalities.     

系统胎儿超声检查在先天畸形诊断中的应用研究

目的 探讨系统胎儿超声检查诊断胎儿畸形的价值.方法 对47 109例孕12～42周的孕妇进行产前超声检查,其中23 901例孕妇开展常规超声检查,23 208例孕妇开展系统胎儿超声检查.对比两种超声检查的畸形检出率,评估系统胎儿超声检查的价值.结果 与常规超声检查比较,系统胎儿超声检查的畸形检出率、心脏畸形检出率、颜面部畸形检出率均提高,≥28孕周畸形胎儿引产率下降,差异均有统计学意义（P＜0.05）.结论 系统胎儿超声检查与常规超声检查比较,畸形检出率高,诊断孕周提前,此方法在产前诊断中起着重要的作用.     

胎儿先天性缺陷的超声诊断价值

目的 正确判断胎儿先天性缺陷的超声特征及预后，及时确诊胎儿畸形，提高人口素质。方法 对我院1999年1－2001年12月本院产科门诊就诊的孕妇，超声诊断胎儿畸形73例。孕妇年龄19－39岁，平均26.70岁。诊断孕周13－34周，平均23.38周。本院引产38例，外院引产19例。足月分娩11例，失访5例。结果 73例畸形儿中，以神经系统畸形居首，其次分别为：唇、腭裂、泌尿系统畸形，水样胎，心血管畸形，腹裂，胎儿肺囊腺瘤样改变（CCAM），骨骼系统畸形等。结论 加强胎儿畸形的产前超前筛查工作规范化管理，提高产前筛查的质量是降低缺陷儿出生的关键。     

孕11～14周正常胎儿心脏经阴道与腹部超声检查的对比研究

目的探讨经阴道超声检查观察孕11～14周胎儿心脏的方法及其诊断价值。方法对158例有高危妊娠病史及胎儿颈项透明层增厚且胎儿心脏正常的孕妇,于孕11～14周采用经阴道超声检查及腹部超声检查进行胎儿心脏检查。结果经阴道超声检查对孕12+0～12+6周、孕13+0～13+6周、孕14+0～14+3周胎儿心脏四腔心、左心室流出道及右心室流出道切面的显示明显优于腹部超声检查,两者相比差异有统计学意义(P0.01,P0.05)。而经阴道超声检查对孕11+0～11+6周胎儿心脏各切面的显示与腹部超声检查相比差异无统计学意义(P0.05)。结论对早孕晚期及中孕早期的高危孕妇行经阴道超声检查有临床应用价值。