Prediction of Fetal Biliary Atresia Based on Second and Third-Trimester Ultrasound Characteristics.

OBJECTIVE: To explore the diagnostic performance of prenatal ultrasound in the prediction of biliary atresia (BA). METHODS: We prospectively collected cases of suspected biliary abnormalities in the 2nd trimester of pregnancy and performed a series (at least 3) of prenatal ultrasound examinations in the 2nd and 3rd trimester. The presence of the gallbladder was examined each time, and its size and shape were assessed if the gallbladder was visible. The existence of other abnormalities was carefully evaluated. Neonatal ultrasound examination was conducted within 1 month after birth, and clinical data were followed-up for 6 months after birth. RESULTS: Among the 41 895 patients, 298 were suspected to have biliary abnormalities, while 82 patients were excluded due to loss to follow-up or induced labor caused by other abnormalities. A total of 216 patients were included in this study, and 15 were diagnosed with BA. We summarized the ultrasound findings of the gallbladders and defined a high-risk gallbladder for the prenatal diagnosis of BA. This was demonstrated to have the best diagnostic performance as a single parameter, with an area under the curve of 0.914 (95 %CI: 0.869-0.948). In addition, higher incidences of biliary cysts, right hepatic artery dilation, echogenic bowel, and ascites were observed in BA fetuses. Logistic regression analysis showed that the combination of 5 parameters had better diagnostic performance, with an area under the curve of 0.995 (95 %CI: 0.973-0.999). CONCLUSION: The fetal gallbladder was found to be a critical feature for the identification of BA. Concomitant abnormalities could be helpful to improve the accuracy of the diagnosis.

Non-invasive dynamic observation of placental vascular anastomoses in monochorionic twins: Assessment using three-dimensional sonography combined with tomographic ultrasound imaging.

INTRODUCTION: Three-dimensional (3D) sonography combined with tomographic ultrasound imaging (TUI) to observe placental vascular anastomoses in monochorionic diamniotic (MCDA) twin pregnancies was evaluated. METHODS: Women with MCDA twin pregnancies at a gestational age of 16-32 weeks were enrolled in this retrospective study. Placental anastomoses were detected using two-dimensional (2D) and 3D sonography. Two-dimensional data were obtained by color and spectral Doppler and 3D data with high-definition flow within the area between twins' umbilical cord insertions. Volume post-processing using TUI mode identified anastomoses. Anastomotic findings on ultrasound were compared with fetoscopic surgery or postnatally injected placentas for diagnostic value. Anastomoses detection was compared between the two imaging modalities. RESULTS: Seventy-six twin pregnancies were analyzed: 11 selective intrauterine growth restrictions (sIUGR), 10 twin-to-twin transfusion syndrome (TTTS), and 55 without complications. Seventy-one twin pregnancies had arterio-arterial (AA) anastomoses and 75 had arterio-venous (AV) anastomoses. Three-dimensional sonography combined with TUI was more sensitive (87.3%) and accurate (88.2%) in detecting AA anastomoses than 2D sonography (74.6%, 76.3%, respectively; P < 0.05), but had comparable sensitivity for AV anastomoses. The specificity of both modalities for anastomoses was 100%. The detection rate of AA anastomoses by 3D modality was (40%) TTTS vs. (87.3%) normal (P < 0.05), but comparable (90.9%) for sIUGR. The detection rates of AV anastomoses (90%, 81.8%) in TTTS and sIUGR were comparable with (87.3%) normal (P > 0.05). DISCUSSION: Three-dimensional sonography combined with TUI highlighted placental anastomoses and may be useful for the clinical diagnosis and therapy of MCDA twin complications.

TAZ and myostatin involved in muscle atrophy of congenital neurogenic clubfoot.

BACKGROUND: Muscular atrophy is the basic defect of neurogenic clubfoot. Muscle atrophy of clubfoot needs more scientific and reasonable imaging measurement parameters to evaluate. The Hippo pathway and myostatin pathway may be directly correlated in myogenesis. In this study, we will use congenital neurogenic clubfoot muscle atrophy model to verify in vivo. Further, the antagonistic mechanism of TAZ on myostatin was studied in the C2C12 cell differentiation model. AIM: To identify muscle atrophy in fetal neurogenic clubfoot by ultrasound imaging and detect the expression of TAZ and myostatin in gastrocnemius muscle. To elucidate the possible mechanisms by which TAZ antagonizes myostatin-induced atrophy in an in vitro cell model. METHODS: Muscle atrophy in eight cases of fetal unilateral clubfoot with nervous system abnormalities was identified by 2D and 3D ultrasound. Western blotting and immunostaining were performed to detect expression of myostatin and TAZ. TAZ overexpression in C2C12 myotubes and the expression of associated proteins were analyzed by western blotting. RESULTS: The maximum cross-sectional area of the fetal clubfoot on the varus side was reduced compared to the contralateral side. Myostatin was elevated in the atrophied gastrocnemius muscle, while TAZ expression was decreased. They were negatively correlated. TAZ overexpression reversed the diameter reduction of the myotube, downregulated phosphorylated Akt, and increased the expression of forkhead box O4 induced by myostatin. CONCLUSION: Ultrasound can detect muscle atrophy of fetal clubfoot. TAZ and myostatin are involved in the pathological process of neurogenic clubfoot muscle atrophy. TAZ antagonizes myostatin-induced myotube atrophy, potentially through regulation of the Akt/forkhead box O4 signaling pathway.

Evaluation of right ventricular volume and systolic function in normal fetuses using intelligent spatiotemporal image correlation.

BACKGROUND: Heart defects are the most common congenital malformations in fetuses. Fetal cardiac structure and function abnormalities lead to changes in ventricular volume. As ventricular volume is an important index for evaluating fetal cardiovascular development, an effective and reliable method for measuring fetal ventricular volume and cardiac function is necessary for accurate ultrasonic diagnosis and effective clinical treatment. The new intelligent spatiotemporal image correlation (iSTIC) technology acquires high-resolution volumetric images. In this study, the iSTIC technique was used to measure right ventricular volume and to evaluate right ventricular systolic function to provide a more accurate and convenient evaluation of fetal heart function. AIM: To investigate the value of iSTIC in evaluating right ventricular volume and systolic function in normal fetuses. METHODS: Between October 2014 and September 2015, a total of 123 pregnant women received prenatal ultrasound examinations in our hospital. iSTIC technology was used to acquire the entire fetal cardiac volume with off-line analysis using QLAB software. Cardiac systolic and diastolic phases were defined by opening of the atrioventricular valve and the subsequent closure of the atrioventricular valve. The volumetric data of the two phases were measured by manual tracking and summation of multiple slices and recording of the right ventricular end-systolic volume and the right ventricular end-diastolic volume. The data were used to calculate the right stroke volume, the right cardiac output, and the right ejection fraction. The correlations of changes between the above-mentioned indices and gestational age were analyzed. The right ventricular volumes of 30 randomly selected cases were measured twice by the same sonographer, and the intra-observer agreement measurements were calculated. RESULTS: Among the 123 normal fetuses, the mean right ventricular end-diastolic volume increased from 0.99 ± 0.34 mL at 22 wk gestation to 3.69 ± 0.36 mL at 35+6 wk gestation. The mean right ventricular end-systolic volume increased from 0.43 ± 0.18 mL at 22 wk gestation to 1.36 ± 0.22 mL at 35+6 wk gestation. The mean right stroke volume increased from 0.62 ± 0.29 mL at 22 wk gestation to 2.33 ± 0.18 mL at 35+6 wk gestation. The mean right cardiac output increased from 92.23 ± 40.67 mL/min at 22 wk gestation to 335.83 ± 32.75 mL/min at 35+6 wk gestation. Right ventricular end-diastolic volume, right ventricular end-systolic volume, right stroke volume, and right cardiac output all increased with gestational age and the correlations were linear (P < 0.01). Right ejection fraction had no apparent correlation with gestational age (P > 0.05). CONCLUSION: Fetal right ventricular volume can be quantitatively measured using iSTIC technology with relative ease and high repeatability. iSTIC technology is expected to provide a new method for clinical evaluation of fetal cardiac function.

An investigation of the standardization of fetal cavum septi pellucidi measurements using three-dimensional volumes of the fetal head.

PURPOSE: The purpose of this study was to measure the maximal width, middle width, and length of the cavum septi pellucidi (CSP) in normal fetuses, and compare these measurements obtained in the transthalamic (TT) plane with those obtained in the transventricular (TV) plane. METHOD: A prospective study was conducted of normal singleton fetuses, ranging from 18 to 36 weeks in gestational age. In each case, a three-dimensional volume of the fetal head was obtained in the TT plane for further offline measurements, then the maximal width, middle width, and length of the CSP in both the TT and TV planes were measured. Intraobserver and interobserver reproducibility was assessed, and curve estimation was used to assess the possible relationship between these measurements of CSP and gestational age (GA). RESULTS: A total of 267 normal fetuses were studied. The CSP width and length in TT and TV planes as a function of GA were analyzed using a quadratic regression model. Intraobserver and interobserver agreement of the CSP measurements was excellent overall (ICCs >0.9), with intraobserver and interobserver differences of less than 4%. CONCLUSION: Measurements of CSP in the TT and TV planes are equally reproducible.

Dilated cavum septi pellucidi as sole prenatal ultrasound defect: Case-base analysis of fetal outcomes.

OBJECTIVES: This retrospective study was undertaken to examine fetuses with dilated cavum septi pellucidi (CSP) as an isolated finding and to identify factors impacting postnatal outcomes. STUDY DESIGN: Fully documented cases of dilated CSP as a sole prenatal defect were selected for study. Recorded data included serial sonographic examinations, fetal MRI studies, chromosomal testing, screening for infection, and postnatal follow-up. Fetal subjects were further stratified by gender, gestational age at diagnosis (<28 w or ≥28 w), CSP width at diagnosis (<10 mm or ≥10 mm), evolution at term (persistent vs non-persistent CSP), and postnatal MRI diagnosis (presence/absence of CSP cyst). Chi-square or Fisher's exact test (as appropriate) was used to compare categorical variables and patient groups. RESULTS: A total of 48 fetuses met our inclusion criteria, none exhibiting chromosomal abnormalities. Six (12.5%) of these 48 were subsequently diagnosed with neurodevelopmental delays. However, such delays were unrelated to any categorical variable listed above (p > 0.05). CONCLUSIONS: Dilated CSP as an isolated prenatal finding by ultrasound or MRI carries a low risk of chromosomal abnormalities but a high risk of neurodevelopmental delay. These perils should be adequately conveyed to the parents of such infants.

Utility of indirect sonographic signs (including cavum septum pellucidum ratio) in midgestational screening for partial agenesis of corpus callosum.

PURPOSE: This study was undertaken to evaluate the performance of indirect sonographic signs in detecting partial agenesis of the corpus callosum (pACC) at midgestation, focusing on the cavum septum pellucidum (CSP) ratio. METHODS: A retrospective case-controlled study of singleton pregnancies was conducted, examining fetuses diagnosed with isolated pACC and normal controls. At midgestational age, fetal head volumes were imaged with 3D US and stored for the evaluation of indirect sonographic findings in axial planes. RESULTS: Fifteen normal and 15 abnormal fetuses (with pACC) were analyzed. Based on a CSP ratio < 1.5, detection of pACC increased from 66.7% (10/15) to 80% (12/15). All indirect signs proved highly suspicious for pACC (risk ratios > 1). CONCLUSION: Use of indirect sonographic signs to screen for pACC at midgestation is challenging. However, a low CSP ratio may improve the detection rate, serving as a new indirect sign.

Relationships of serum placental growth factor and soluble fms-like tyrosine kinase-1 with fetal and uterine artery Doppler indices in pre-eclampsia.

OBJECTIVE: To compare serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) concentrations among women with pre-eclampsia and healthy control women and to evaluate the associations of serum PlGF and sFlt-1 with fetal and uterine artery Doppler indices in pre-eclampsia. METHODS: A prospective cross-sectional study of 33 women with pre-eclampsia and 33 normotensive pregnant women attending a university hospital in China between January and November 2014. Serum PlGF and sFlt-1 were assayed by enzyme linked immunosorbent assays. Doppler indices of the uterine artery, umbilical artery, fetal middle cerebral artery, and ductus venosus were measured. RESULTS: The pulsatility index of the uterine artery was negatively correlated with PlGF (r, -0.487; P=0.004) and positively correlated with sFlt-1 (r, 0.420; P=0.015). Gestational age at birth was positively correlated with PlGF (r, 0.601, P<0.001) and negatively correlated with sFlt-1 (r, -0.568; P=0.001). Birth weight was positively correlated with PlGF (r, 0.555; P=0.001) and negatively correlated with sFlt-1 (r, -0.552; P=0.001). Apgar score was negatively correlated with sFlt-1 (r, -0.427; P=0.017). CONCLUSION: Lower PlGF and higher sFlt-1 levels in maternal serum were significantly associated with increased uterine arterial impedance in pre-eclampsia.

A method for quantitative 2-dimensional sonographic analysis of the fetal conus medullaris position.

OBJECTIVE: This study explored the use of 2-dimensional (2D) ultrasound scans for the quantitative assessment of the fetal conus medullaris (CM) position and its correlation with gestational age (GA). METHODS: This was a prospective study. We identified the first sacral vertebra (S1) by intersection of 2 lines in 2D scans, then counted upward from S1 to determine the CM level and recorded the number of ossified sacral vertebral bodies. A quantitative assessment of the CM position was performed by measuring the distance between the CM and the midpoint of the S1 (CM-S1). The correlation between the CM-S1 distance and GA was evaluated. RESULTS: We determined the CM level by identifying S1 first in 521 fetuses (GA, 20-38 weeks). The CM position in 70% of cases was at the L2 and L2-3 level, and at the L2 level or above after 37 weeks. The number of ossified sacral veterbral bodies was not consistent. CM-S1 measurements were easy to perform. A significant positive correlation between CM-S1 distance and GA was observed (R2 = .89, P < .05). The best-fit formula was: CM-S1 distance = 1.57 × GA - 16.43. The normal reference range was established and the fifth percentile was calculated for each GA. CONCLUSIONS: S1 was easily identified, and the CM position relative to S1 was useful. There was a substantial correlation between CM-S1 and GA. Below the fifth percentile it was suggested that tethered cord may exist.

Carotid arterial wall stiffness correlates positively with impedance of the umbilical and uterine arteries in women with preeclampsia.

PURPOSE: This study aimed to determine whether the stiffness of the arterial walls of women with preeclampsia (PE) differs from that of healthy controls and to evaluate its association with fetal and uterine artery Doppler variables and perinatal outcomes in PE. METHODS: We enrolled 30 women with PE and 30 normotensive pregnant women. Carotid artery stiffness and Doppler variables of the uterine, umbilical, and fetal middle cerebral arteries and the ductus venosus were measured in both groups. Measurements of the common carotid artery were performed by the Aloka ultrasonic echo-tracking technique. RESULTS: Stiffness of the carotid artery wall of women with PE was significantly higher than that of healthy controls. It was positively correlated with the pulsatility index of the uterine and umbilical arteries and negatively correlated with the cerebroplacental ratio in women with PE. In women with PE, the carotid artery augmentation index showed negative correlations with birth weight and Apgar score. CONCLUSIONS: The stiffness of the carotid arteries of women with PE is increased, and this increase is positively correlated with the impedance of the umbilical and uterine arteries.

Three-dimensional power Doppler ultrasound evaluation of placental blood flow in normal monochorionic diamniotic twin pregnancies.

BACKGROUND: Monochorionic diamniotic (MCDA) twin pregnancies are at higher risk of adverse outcomes and complications, which are attributed to the influence of placental morphology in MCDA twins. Monitoring of placental function is an important index for clinical decisions. The aim of our study was to evaluate the placental blood flow estimated using three-dimensional power Doppler (3D-PD) ultrasound and the vascular indices distribution with gestational age (GA) in normal MCDA twin pregnancies. METHODS: One hundred four MCDA twin pregnancies and 106 singleton pregnancies (GA range, 14-32 weeks) were included in this prospective study. 3D-PD volume data of each fetus was obtained separately from the placenta at the site of umbilical cord insertion. We analyzed the volume data using sonobiopsy technique. The placental vascularization index (VI), flow index (FI) and vascularizationflow index (VFI), were auto-calculated. The means and standard deviation values of three vascular indices per fetus were calculated and regression analysis of the vascular indices as a function of GA was performed in twin pregnancies. The vascular indices of twin and singleton pregnancies were compared using independent t-test. RESULTS: There were no significant differences in VI, FI or VFI among the fetuses of twins (p > 0.05). These vascular indices increased over the course of pregnancy (p < 0.05). We obtained the regression equations for the indices as a function of GA in days: VI = exp. (4.369-28.533/GA) (R2 = 0.699, p < 0.05), FI = exp. (3.916-13.003/GA) (R2 = 0.511, p < 0.05), and VFI = exp. (3.577-37.468/GA) (R2 = 0.675, p < 0.05). There were no significant differences in three vascular indices between MCDA twin and singleton groups (p > 0.05). CONCLUSIONS: 3D-PD placental data using sonobiopsy technique could reflect the placental blood flow of each twin, which could be applied to the study of placental perfusion in MCDA twin pregnancies. This study also presented the vascular indices distribution with GA in normal twin pregnancies, which might be useful for early detection of MCDA complications.

Presence of chromosomal abnormalities in fetuses with isolated ventriculomegaly on prenatal ultrasound in China.

BACKGROUND: The purpose of our study was to compare the incidence of chromosomal abnormalities of fetuses with isolated fetal ventriculomegaly (VM) to that of fetuses with the sole risk factor of being born to mothers of advanced age. METHOD: This prospective study included two groups. Group 1 included fetuses with isolated VM and were further categorized according to maternal age, fetal gender, laterality of VM (unilateral or bilateral), evolution of VM (resolved or persistent or progressive), and the gestational age at the time of diagnosis (<28w or ≥28w). Group 2 were fetuses without any fetal structural abnormality, but maternal age was at or over 35 years. RESULT: Eighteen fetuses (18/231, 7.8%) with chromosomal abnormalities were identified for Group 1, and 13 fetuses (13/782, 1.7%) were identified for Group 2. When cases with mothers of advanced age were excluded from Group 1, the incidence of chromosomal abnormalities of isolated VM fetuses age was 7.2%, which is still higher than that of normal structural fetuses in mothers of advanced age (p < 0.001). CONCLUSION: The risk of chromosomal abnormalities for fetuses with isolated VM is high, especially when it is severe, bilateral, the first presence occurs in mid-gestation and is not resolved.

Quantitative assessment of placental perfusion by three-dimensional power Doppler ultrasound for twins with selective intrauterine growth restriction in one twin.

OBJECTIVE: We quantitatively assessed placental perfusion using three-dimensional (3D) power Doppler ultrasound for twins with selective intrauterine growth restriction (sIUGR) in one twin. STUDY DESIGN: A prospective cross-sectional study was performed for 104 normal monochorionic diamniotic twins and 30 twins with sIUGR. Twins with sIUGR were divided into two groups: in group I (19 twins), both fetuses had continuous forward end-diastolic blood flow in the umbilical artery; in group II (11 twins), the smaller fetus had a loss or a reverse end-diastolic blood flow in the umbilical artery, but the larger fetus had continuous forward end-diastolic blood flow. Volume data of the placenta was acquired in each twin at the plane where the umbilical cord entered the placenta by 3D power Doppler ultrasound, and imaging software was used to calculate the placental vascularization index (VI), flow index (FI), and vascularization flow index (VFI). RESULTS: Among smaller fetuses, the sIUGR and control groups showed significant differences in VI and VFI, as well as significant differences between sIUGR group II and control group in FI. No such differences in placental perfusion were found among larger fetuses. CONCLUSIONS: 3D power Doppler ultrasound could sensitively display the varying degrees of changes in placental perfusion, which could be used for clinical monitoring of placental perfusion in sIUGR twins.

Measurement of normal fetal cerebellar vermis at 24-32 weeks of gestation by transabdominal ultrasound and magnetic resonance imaging: A prospective comparative study.

OBJECTIVES: Fetal cerebellar vermis may be assessed by ultrasound (US) or magnetic resonance imaging (MRI), and median-plane views are best for evaluation. The purpose of this study was to compare measurements of normal fetal vermis at 24-32 weeks of gestation obtained in median plane by transabdominal 2D-US, 3D-US, and MRI. METHODS: A prospective study was conducted, examining normal singleton fetuses between 24 and 32 weeks of gestation. Within a 24-h period, median-plane views of posterior fossa were generated using 2D-US, 3D-US, and MRI. Measurements of anteroposterior (AP) diameter, craniocaudal (CC) diameter, mid-sagittal surface area, brainstem-vermis (BV) angle and brainstem-tentorium (BT) angle were obtained to compare these imaging modalities. RESULTS: A total of 180 fetuses were studied. Correlation among imaging methods was good, marked by the following intraclass correlation coefficients: AP diameter, 0.955; CC diameter, 0.956; mid-sagittal surface area, 0.982; BV angle, 0.810; and BT angle, 0.865 (p < 0.001). CONCLUSIONS: Visualization rates of MRI, 3D-US, and transabdominal 2D-US were decremental, MRI being superior in this regard. However, these three imaging modalities correlated well in measuring cerebellar vermis and its surroundings.

Prenatal Assessment of the Position of Fetal Conus Medullaris as a Predictor of Fetal Spinal Lesions.

OBJECTIVES: The aim of this study is to compare two different methods in assessment of the position of fetal conus medullaris (CM) and to explore the significance for assessment of CM. METHODS: This study included both normal fetuses and those with the diagnosis of fetal spinal lesions. The position of fetal CM was performed sonographically using two methods: location of CM in relation to the vertebral body (CM level) and measurement of the conus sacrum (CS) distance. RESULTS: The results showed that intra-observer and interobserver concordance was high for the two methods, both in the normal and abnormal groups. There was significant association between femur length and CS distance (R2 = 0.917) and between gestational age and CS distance (R2 = 0.892). CONCLUSIONS: We propose the combined use of CM level location and CS distance measurement for the prenatal diagnosis of fetal spinal lesions for complementary needs.

The Value of Prenatal Ultrasonographic Diagnosis of Diastematomyelia.

OBJECTIVES: To evaluate the value of prenatal ultrasonographic diagnosis of diastematomyelia, and to provide a basis for the diagnosis and differential diagnosis of fetal diastematomyelia. METHODS: Four fetuses with suspected diastematomyelia based on prenatal ultrasonography are presented. Detailed prenatal ultrasonography was performed to examine spinal cord abnormalities. The region of interest-based spine sagittal plane was defined and 3D volumetric scans were performed, as needed. Images were stored and compared with MRI or ultrasonographic images after abortion. RESULTS: In the four cases of diastematomyelia diagnosed by prenatal ultrasonography, two were confirmed by MRI after birth, and the other two were confirmed by autopsy and pathologic examination after abortion. Varying degrees of spine or spinal cord deformities were noted. Two pregnancies were terminated, and two newborns underwent surgery. CONCLUSIONS: Prenatal ultrasonography contributes to the diagnosis of diastematomyelia and provides a basis for prenatal counseling and prognosis.

Identification of fetal cardiac anatomy and hemodynamics: a novel enhanced screening protocol.

BACKGROUND: Prenatal cardiac screening is of great importance as it contributes to appropriate neonatal management and helps parents to make a decision regarding their pregnancy. The aim of our study was to evaluate the efficiency of a newly proposed screening protocol in the detection of fetal congenital heart disease (CHD). METHODS: This was a prospective study. A total of 52 cases of confirmed CHD fetuses and 248 cases of randomly selected normal fetuses were included in the study. Two sonographers with similar experience performed the cardiac screenings under two different protocols independently. The conventional protocol (Protocol A) paid greater attention to the four-chamber view and the outflow tract views. A 6-month training program was provided to sonographers performing scans under the new protocol (Protocol B), which emphasized systematically evaluating fetal cardiac anatomy and hemodynamics. Color Doppler was mandatory and some ultrasonic signs for special cardiac anomalies were also introduced into this protocol. RESULTS: Protocol B detected more cardiac anomalies than did Protocol A (96.2 % vs. 61.5 %, P < 0.01). Specifically, Protocol B was superior to Protocol A in detecting cardiac malpositions, abnormal systemic and pulmonary venous connection, right aortic arch, transposition of the great arteries, and congenital corrected transposition of the great arteries. By visualizing flow disturbance and retrograde flow with color Doppler, Protocol B was better than Protocol A in screening valvular associated malformations, such as pulmonary atresia, pulmonary stenosis, tricuspid dysplasia, etc. For the normal fetuses, Protocol B was better than Protocol A in reducing the false-positive detection of septal defects. CONCLUSIONS: The current study introduces an enhanced protocol for fetal cardiac screening, under which the obstetric screening sonographers systematically identify fetal cardiac anatomy and hemodynamics. A short-term training program makes it possible for the screening sonographers to become familiar with the new protocol, and its value has been confirmed due to improvements made in screening efficiency.

Prenatal Diagnosis of Fetal Interrupted Aortic Arch Type A by Two-Dimensional Echocardiography and Four-Dimensional Echocardiography with B-Flow Imaging and Spatiotemporal Image Correlation.

BACKGROUND: Fetal interrupted aortic arch (IAA) is a rare cardiac anomaly and its prenatal diagnosis is challenging. The purpose of our report is to evaluate the use of two-dimensional echocardiography (2DE) and 4D echocardiography with B-flow imaging and spatiotemporal image correlation (4D BF-STIC) in detecting IAA type A (IAA-A). MATERIALS & METHODS: Twenty-three cases of confirmed IAA-A identified by fetal echocardiography were involved in the study. The fetal echocardiography image data were reviewed to analyze the ratio of right ventricle to left ventricle (RV/LV) diameter, the ratio of main pulmonary artery to ascending aorta (MPA/AAO) diameter, and the correlation of RV/LV diameter ratio and size of ventricular septal defect (VSD). 4D BF-STIC was performed in 21 fetuses using the sagittal view (4D BF-STIC-sagittal) and the four-chamber view (4D BF-STIC-4CV) as initial planes of view. An additional 183 normal fetuses were also included in our study. RV/LV and MPA/AAO ratios were calculated and compared with that of IAA-A fetuses. Fetal 2DE, 4D BF-STIC-sagittal, and 4D BF-STIC-4CV were used to visualize the aortic arch and its associated neck vessels. Six subgroups were evaluated according to gestational age. RESULTS: Fetal 2DE, 4D BF-STIC-sagittal, and 4D BF-STIC-4CV made the correct prenatal diagnosis of IAA-A in 19/23 (82.6%), 14/21 (66.7%), and 19/21 (90.5%) of patients, respectively. A significantly enlarged MPA combined with symmetric ventricles was found in the IAA-A fetuses, while the size of the VSD was negatively correlated with RV/LV ratio. 4D BF-STIC-sagittal and 4D BF-STIC-4CV were better than traditional 2D ultrasound in detecting the aortic arch and neck vessels between 17 and 28 gestational weeks and 29 to 40 gestational weeks in normal fetuses. CONCLUSION: It is demonstrated that IAA-A could be diagnosed by traditional fetal echocardiography, while 4D technique could better display the anatomic structure and the spatial relationships of the great arteries. Use of volume reconstruction may promote its clinical usage and help prenatal diagnosis.

Evaluation of the development of the fetal anal sphincter with tomography ultrasonography imaging.

The aim of the study described here was to examine the potential of tomography ultrasonography imaging (TUI) in evaluation of the fetal anal sphincter. In this prospective cross-sectional study of the fetal anal sphincter with TUI, 326 singleton pregnancies (mean age = 28 y, range: 22-38 y) were scanned at 19-40 wk of gestation. The fetal anal region and ischium were revealed in 320 of 326 patients (98.2%). The normal fetal anal sphincter diameter and ischial space reached maximums of 15 and 39 mm, respectively. The normal fetal anal sphincter diameter and the ischial space were plotted as a function of gestational age (GA) on a linear curve, and the regression equations for normal fetal anal sphincter diameter and ischial space as a function of GA in weeks were obtained. A scatterplot was also created that revealed a significant positive relationship between normal fetal anal sphincter diameter and ischial space. On the basis of these criteria, imperforate anus was diagnosed in one fetus. Ultrasonographic assessment of the fetal anal sphincter and the ischium with TUI is feasible. The reference values reported in this article may be useful in prenatal diagnosis of fetal anal sphincter abnormalities.