Prenatal color Doppler sonographic evaluation of nuchal encirclement by the umbilical cord

PURPOSE: The aim of this study was to assess whether Doppler flow velocimetry of the fetal middle cerebral and umbilical arteries is affected by nuchal encirclement by the umbilical cord (nuchal cord) in the prenatal period. PATIENTS AND METHODS: The position of the fetal umbilical cord was assessed on color Doppler sonography in pregnant women who were referred to our radiology department between September 14, 1998, and January 14, 2000. Pulsatility and resistance indices and the ratio of peak systolic blood flow velocity to diastolic velocity of the umbilical arteries and middle cerebral arteries of all fetuses were prospectively obtained with Doppler flow velocimetry. The fetuses were categorized into 2 groups: group 1 consisted of fetuses without sonographic evidence of nuchal cord and group 2 of fetuses with sonographic evidence of nuchal cord. The results were statistically analyzed with independent-groups t test. A p value of less than 0.05 was considered significant. RESULTS: During the study period, 230 pregnant women underwent sonographic examination of the fetus, and 68 fetuses were delivered. The sonographic examinations were performed at 24-41 weeks' menstrual age. Of the 46 fetuses in group 1, 1 fetus had nuchal cord at delivery; of the 22 fetuses in group 2, 4 did not have nuchal cord at delivery. The sensitivity of color Doppler sonography in detecting nuchal cord was 95% (18 of 19 fetuses), the specificity was 92% (45 of 49), the negative predictive value was 98% (45 of 46), and the positive predictive value was 82% (18 of 22). No statistically significant differences in middle cerebral artery or umbilical artery Doppler flow velocimetry values were detected between the 2 groups. CONCLUSIONS: Color Doppler sonography is a sensitive and specific method of diagnosing nuchal cord, but fetal middle cerebral artery and umbilical artery Doppler flow velocimetry values are not affected by the presence of nuchal cord in the prenatal period.     

The value of repeated evaluation after initial failed nuchal translucency measurement.

OBJECTIVE: The purpose of this study was to assess the value of reattempting the nuchal translucency (NT) measurement after an initial failure. METHODS: Women undergoing NT measurements by NT-certified sonographers within a combined screening program over an 18-month period were categorized as "desiring" screening (all women), "eligible" (live fetus with crown-rump length of 45-84 mm), and "defaulters" (failed to keep a visit after a failed NT measurement attempt). If the NT measurement was unobtainable, patients with live fetuses and a crown-rump length of less than 84 mm were offered reexamination. RESULTS: Nuchal translucency measurement success rates at the initial visit for those desiring (n = 837) and eligible (n = 767) were 73.3% and 80.0%, respectively. Composite NT measurement success rates for up to 3 visits were significantly greater than for only 1 visit for those desiring screening (84.8%; P < .0001), eligible for screening (86.6%; P = .0004), and not defaulting on follow-up (97.0%; P < .0001). The screen-positive rates were similar for 1 and up to 3 visits (10.4% and 11.0%). One additional (16.6%) aneuploidy was detected through a second visit. CONCLUSIONS: Reattempting NT measurements significantly increases the overall NT measurement success rate and detects additional aneuploidies at constant screen-positive and invasive prenatal diagnosis rates.     

Prenatal diagnosis of Pfeiffer syndrome type 2 with increased nuchal translucency

Pfeiffer syndrome (PS) is a rare autosomal dominant genetic disorder characterized by craniosynostosis, broad thumbs / toes. Here, we report a case of PS type 2 with increased nuchal translucency in early trimester.     

Feasibility of nuchal translucency in triplet pregnancies.

OBJECTIVE: To assess the feasibility of nuchal translucency in triplets compared with singletons. METHODS: Nuchal translucency thickness as part of routine first-trimester screening in the general population was compared between 3128 singleton pregnancies and 51 triplets (153 fetuses). Crown-rump length was also noted. The 5th, 50th, and 95th percentiles were determined and compared between the 2 groups, and regression curves of nuchal translucency measurements plotted against crown-rump length were drawn. RESULTS: The mean nuchal translucency thickness was 1.23 mm for singletons and triplets. The 5th and 95th percentiles were also the same between the 2 studied groups. The regression curves of 5th, 50th, and 95th percentiles of nuchal translucency plotted against crown-rump length of triplets and singletons overlapped. CONCLUSIONS: Nuchal translucency values and distribution are the same in triplets and singletons, validating the utility of the cutoff values.     

Prenatal sonographic diagnosis of short umbilical cord in a dichorionic twin with normal fetal anatomy

Short umbilical cords are associated with fetal anomalies, often including those with decreased or absent fetal movement, fetal akinesia/hypokinesia sequence, and restrictive dermopathies and aneuploidy. In normal fetuses, abnormally short umbilical cords have been associated with an increased risk of umbilical vessel hematomas, thrombosis, rupture, thrombocytopenia, cord compression, variable fetal heart rate decelerations, instrumental and operative deliveries, and fetal demise. We report a 24‐year‐old gravida 2, para 0 with a concordant dichorionic twin gestation, at 26 weeks' gestation, in whom sonography depicted fetuses with normal‐appearing anatomy as well as short umbilical cord of the 1st twin. Increased fetal surveillance was conducted. Following delivery at 36 weeks' gestation, the presence of a short umbilical cord of the 1st twin measuring 19 cm was confirmed. Systematic review of the literature confirms that this is the first report of prenatal diagnosis of a short umbilical cord in an otherwise normal fetus. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound 2010     

Three-dimensional power Doppler sonography in the prenatal diagnosis of a true knot of the umbilical cord: value and limitations.

OBJECTIVE: The purpose of this study was to examine the value of 3-dimensional power Doppler sonography in the prenatal diagnosis of a true knot of the umbilical cord. METHODS: Cases in which the diagnosis of a true knot of the umbilical cord was suspected by prenatal 2-dimensional sonography were reviewed. The presumably affected segment of the cord was examined with 3-dimensional power Doppler sonography for further characterization. Confirmation of the prenatal diagnosis was sought by reviewing the delivery records and contacting the referring obstetrician and the patients themselves. RESULTS: Eight consecutive cases were studied. Three-dimensional power Doppler sonography displayed a vascular spatial configuration pattern consistent with a true knot of the umbilical cord in all of them. However, the prenatal diagnosis was confirmed at delivery in only 5 cases (62.5%). Although there were no cases of a false knot mimicking a true knot of the umbilical cord, all incorrect diagnoses in this series were associated with multiple loops of the umbilical cord in the third trimester. CONCLUSIONS: Three-dimensional power Doppler sonography seems to be helpful in determining the presence of a true knot of the umbilical cord in utero, especially in the second trimester. However, this should not be considered a definitive method for the diagnosis because multiple loops of the umbilical cord lying close to each other can generate a sonographic image that can be undistinguishable from a true knot of the umbilical cord prenatally, especially when located in a small pocket of amniotic fluid. Therefore, the presumable diagnosis of a true knot of the umbilical cord in utero should be taken with caution.     

超声监测单绒毛膜囊双羊膜囊双胎脐带胎盘附着预测胎儿预后的价值

目的探讨产前超声监测单绒毛膜囊双羊膜囊(MCDA)双胎脐带胎盘附着预测妊娠结局的临床应用价值。方法回顾性分析127名MCDA双胎妊娠孕妇的产前超声检查结果和产后临床资料,比较两胎儿脐带胎盘附着一致组(59名)和不一致组(68名)的复杂性双胎发生率。结果脐带胎盘附着不一致组复杂性双胎的发生率为51.47%(35/68),脐带胎盘附着一致组为23.73%(14/59),差异有统计学意义(P<0.05);其中双胎之一脐带帆状附着的复杂性双胎发生率为59.09%(13/22),双胎之一脐带边缘附着的复杂性双胎发生率为47.83%(22/46),差异无统计学意义(P=0.444);双胎之一帆状附着中双胎输血综合征(TTTS)的发生率为40.91%(9/22),双胎之一边缘附着中TTTS的发生率为13.04%(6/46),差异有统计学意义(P<0.05)。结论产前超声监测MCDA双胎脐带胎盘附着能预测胎儿预后。     

基于孕11~13+6周不同颈项透明层厚度增加标准建立模型筛查高风险人群21-三体综合征

目的 观察11~13⁺⁶孕周21-三体综合征胎儿超声表现，探讨应用不同颈项透明层（NT）增厚标准建立的模型针对高风险人群筛查11~13⁺⁶孕周21-三体综合征胎儿的效能。方法 回顾性分析经胎儿染色体检查确诊为21-三体综合征的106胎（阳性组）及染色体正常（阴性组）1 391胎孕11~13⁺⁶周胎儿。记录2组超声标记出现情况。采用不同NT增厚标准（NT>第95百分位数、NT≥3.0 mm及NT≥3.5 mm）建立筛查21-三体综合征胎儿回归方程，评价其一致性及筛查效能。结果 阳性组72胎（72/106，67.92%）出现超声标记，以NT增厚（>第95百分位数）[70/106（66.04%）]最多见；阴性组89.58%（1 246/1 391）胎儿超声未见异常。以NT>第95百分位数定义NT增厚，筛查胎儿21-三体综合征的敏感度为66.04%，高于以NT≥3.0 mm（χ²=18.05）及NT≥3.5 mm（χ²=23.04）为标准（P均<0.01）。Logistic回归分析显示，孕妇高龄、胎儿NT增厚、鼻骨缺失及胎儿水肿4项指标为筛查胎儿21-三体综合征的有效标记（P均<0.05）。以不同NT增厚标准制定筛查21-三体综合征回归方程，以NT>第95百分位数与NT≥3.0 mm为NT增厚标准制定方程的拟合优度好（χ²=4.45、0.83，P=0.11、0.36），其筛查21-三体综合征胎儿敏感度、特异度及AUC分别为66.00%、90.50%、0.78和50.00%、92.80%及0.70（P均<0.05）。结论 以NT>第95百分位数为胎儿NT增厚标准制定的回归方程筛查高风险人群11~13⁺⁶周胎儿21-三体综合征的效能较佳。     

Prenatally detected umbilical cord tumor as a sign of diffuse neonatal hemangiomatosis

We report a case of a prenatally detected hemangioma of the umbilical cord as an early sign of diffuse neonatal hemangiomatosis (DNH). The newborn was diagnosed with multiple hemangiomas in the liver, intestines, skin, and brain. Prenatal ultrasound findings, neonatal appearance of the hemangiomas, and the associated complications are illustrated. Interdisciplinary investigations as well as operative and systemic treatment approaches proved to be challenging. This case illustrates how prenatal ultrasound with color Doppler facilitates the early diagnosis of DNH and can help through the early referral to specialized centers for appropriate treatment.     

彩色多普勒对脐绕颈胎儿脐动脉及大脑中动脉血流检测分析

目的　分析脐绕颈胎儿脐动脉 (UA)及大脑中动脉 (MCA)的血流参数 ,为临床判断胎儿脑供血情况提供客观依据。方法　比较 44例脐绕颈剖腹产胎儿与 61例脐绕颈自然分娩胎儿的脐动脉及大脑中动脉血流多普勒参数 ,以RI及VP为分析指标。结果　该两组脐绕颈胎儿UA的RI及VP有显著性差异 ,MCA的RI有显著性差异 ,剖腹产胎儿MCA的血流特点为阻力增高 (RI 0 67± 0 0 2 )。结论　脐绕颈胎儿MCA的血流阻力增高 (RI >0 65 )应作为剖腹产术的临床参考指标     

彩色多普勒超声及X线平片对异位骨化诊断的比较

目的比较彩色多普勒超声(彩超)及X线平片检查对脊髓损伤后异位骨化的早期诊断价值。方法对39例临床可疑异位骨化的脊髓损伤患者,在发生下肢水肿48h内进行首次彩超检查,每周复查,直至出现明确钙化灶。39例患者均同时进行X平片检查。结果脊髓损伤后异位骨化彩超所见:正常肌肉板层状结构肿胀增厚或被紊乱不规则结构取代,回声增强34例;出现弧形或长条形强回声带后伴声影39例;肌层内出现无回声血肿8例。外压性血管狭窄,流速增高4例。动态变化表现为:下肢水肿48h内,受累肌层肌纤维肿胀,回声增强,或病变中央区出现局限、形态不规则的非特异性低回声区;下肢水肿1周出现岛状回声增强区;1～2周后,出现大片弧形或长条形强回声带后伴声影,表面光滑或凹凸不平。下肢水肿1周内,彩超对异位骨化的检出率比X平片明显提高(P<0.01)。结论彩色多普勒超声可在患者起病初期检出阳性表现,是早期诊断异位骨化的可靠方法。     

Nomogram of maxillary bone length in normal pregnancies.

OBJECTIVE: The aim of this study was to define normal ultrasonographic growth of the fetal maxillary bone throughout pregnancy as a basis for further studies and as normative data for assessing deviations in growth. METHODS: A prospective cross-sectional study was performed. Consecutive routine biometric measurements and fetal organ scans were obtained from patients undergoing elective fetal anatomic surveys. Special attention was paid to the profile view of the fetal face, and the maxillary bone was identified and measured. RESULTS: Three hundred twenty-seven fetuses between 13 and 40 weeks' gestation were scanned. The maxillary bone is seen as a rodlike structure; it is a part of the facial skeleton that allows the opening and closing of the pharynx. A linear growth function was observed across gestational age (GA), and first-degree correlation was found to exist between GA and the maxillary bone (r = .645; P < .0001; y = 7.78 + 0.18 x GA). Significant correlation was also found between the maxillary bone and biparietal diameter (BPD) (r = 0.652; P > .0001; y = 8.36 + 0.66 x BPD), head circumference (HC) (r = .645; P < .0001; y = 8.39 + 0.18 x HC), femoral bone length (FBL) (r = .640; P < .0001; y = 9.28 + 0.7 x FBL), and abdominal circumference (AC) (r = .640; P < .0001; y = 8.91 + 0.17 x AC). CONCLUSIONS: Normative data for ultrasonographic measurements of the fetal maxillary bone throughout pregnancy are provided. These data potentially allow the prenatal diagnosis of abnormal maxillary bone length.     

Color Doppler sonographically guided transthoracic needle aspiration of lung and mediastinal masses.

OBJECTIVE: This study investigated the diagnostic value of color Doppler sonographically guided transthoracic needle aspiration in lung and mediastinal masses. METHODS: B-mode and colorDoppler sonographic images were obtained in 48 patients with mediastinal or peripheral pulmonary tumors. Color Doppler sonography was used to show the vascular structures before the transthoracic needle aspiration procedure. It was also used to locate the needle tip during the procedure by showing the twinkling sign. This maneuver was performed with motion of the inner stylet. Pathologic and microbiological examination of the aspirates was made. RESULTS: Vascular structures were detected in 37 cases on color Doppler images and in 10 cases on B-mode images. Similarly, the needle tip was observed in 39 cases on color Doppler images but in only 9 cases on B-mode images. No complications were observed except partial pneumothorax in 2 cases. The method had sensitivity of 90.0%, specificity of 87.5%, a positive predictive value of 97.2%, a negative predictive value of 63.6%, and diagnostic accuracy of 89.6%. CONCLUSIONS: Color Doppler sonographically guided transthoracic needle aspiration is a safe diagnostic method in malignant lung tumors, especially peripheral tumors, because of its ability to differentiate vascular structures within a tumor before the transthoracic needle aspiration procedure. It provides additional information about the location of the needle tip.     

Various Doppler sonographic appearances and challenges in prenatal diagnosis of vasa praevia

Rupture of vasa praevia is associated with a high rate of fetal or neonatal mortality. Since the recent development of color and spectral Doppler sonography, prenatal diagnosis of vasa praevia has been increasing but is not yet consistent. We report 2 cases that were diagnosed prenatally, enabling cesarean section to be performed under optimal conditions to prevent complications. A better knowledge of the characteristic Doppler sonographic appearances and the risk factors associated with vasa praevia could greatly facilitate the prenatal diagnosis of this condition and hence the fetal prognosis.     

彩色多普勒超声对精索静脉曲张硬化治疗效果的评价

应用彩色多普勒血流显像（ＣＤＦＩ）研究了３８例经静脉造影证实的左侧精索静脉曲张硬化治疗前后蔓状静脉丛血流动力学改变。结果表明：ＣＤＦＩ和静脉造影一样应以返流征象作为本病诊断的主要条件；术后１０～１２个月作疗效评价较为恰当；触诊检查过低地估计了精索静脉曲张的存在和复发率。我们认为ＣＤＦＩ不仅对精索静脉曲张能作出精确诊断和病理生理学分型，而且能为疗效评价提供客观指标。     

Fetal magnetic resonance imaging enhances detection of spinal cord anomalies in patients with sonographically detected bony anomalies of the spine.

OBJECTIVE: Although fetal magnetic resonance imaging (MRI) is being increasingly used to evaluate sonographically suspected abnormalities, its utility in the evaluation of the spinal canal is not well studied. Because it is not susceptible to the limitations of fetal position, oligohydramnios, and shadowing from bony structures, we hypothesize that fetal MRI is better suited to assess the contents of the spinal canal compared with prenatal sonography. The purpose of this investigation was to determine whether fetal MRI could detect spinal abnormalities in cases in which they had not been originally suspected on prenatal sonography. METHODS: Fetal spine MR images were retrospectively reviewed over a 42-month period. Corresponding sonographic images were then rereviewed to determine whether there were findings in retrospect that might have suggested the cord abnormalities. Cases of myelomeningocele were counted as a spinal cord abnormality only if fetal MRI showed a cord anomaly other than the myelomeningocele. RESULTS: Of 33 cases referred for bony anomalies of the spine, fetal MRI showed additional abnormalities involving the spinal cord in 3 patients. These included diastematomyelia in 2 cases and segmental spinal dysgenesis in the third case. One case of diastematomyelia occurred in association with a lumbosacral myelomeningocele. The spinal cord anomalies were not visible on any of the prenatal sonograms, even in retrospect. CONCLUSIONS: Additional spinal cord anomalies were detected in 10% of cases reviewed. Fetal MRI can be useful in assessing the spinal cord in fetuses with bony spinal anomalies. Our findings suggest that fetuses with sonographically diagnosed bony abnormalities of the spine may benefit from further evaluation with fetal MRI.     

高位脊髓损伤患者大脑动脉血流检测分析

目的：检测高位脊髓损伤患者伤后不同时期大脑动脉血流速度变化特点。方法：对47例不同时期高位脊髓损伤患者进行彩色多普勒超声检查。结果：伤后3—6个月与6个月以上患者的舒张末期血流速度有显著差异。结论：脊髓损伤患者大脑动脉血流改变，对临床治疗有意义。     

An 8-center study to evaluate the utility of mid-term genetic sonograms among high-risk pregnancies.

OBJECTIVE: A multicenter study was undertaken to evaluate the diagnostic efficacy of a genetic sonogram. METHODS: Eight centers provided data on 176 pregnancies complicated by fetal Down syndrome. One hundred thirty-four pregnancies were considered high risk because of advanced maternal age (> 35 years), and 42 were considered high risk for having "abnormal" triple-screen results (risk > 1:250). Each center provided fetal biometric data, information regarding the presence or absence of major structural abnormalities, and between 3 and 6 additional ultrasonographic markers for trisomy 21. The heterogeneity of our 8 independent "sensitivity estimates" was evaluated by Poisson regression, and a single combined estimate of the sensitivity was calculated. RESULTS: Of the total 176 cases of trisomy 21, 125 fetuses (71.0%) had either an abnormal long bone length (femur length, humerus length, or both), a major structural abnormality, or a Down syndrome marker. The combined diagnostic sensitivity was 71.6%, with a range of 63.6% (7 of 11) to 80% (8 of 10). Five centers had sensitivity estimates falling between 64% and 76%. The sensitivity of individual markers varied between 3% (sandal gap) and 46.5% (nuchal skin fold thickness). A condensed regimen of nuchal skin fold thickness, femur length, and a standard anatomic survey would screen in 56.8% of fetuses with Down syndrome. CONCLUSIONS: This 8-center study that included many fetuses with Down syndrome validates the concept that the genetic sonogram can be used to better adjust the Down syndrome risk for high-risk patients.