Automated retrieval of standard diagnostic fetal cardiac ultrasound planes in the second trimester of pregnancy: a prospective evaluation of software.

OBJECTIVE: To evaluate prospectively the performance of software that automatically retrieves, from a three-dimensional (3D) volume of the fetal chest, three diagnostic cardiac planes in the second trimester of pregnancy. METHODS: 3D static volumes of the fetal chest were acquired at the level of the four-chamber view in 72 fetuses between 18 and 23 weeks of gestation. Standardization of 3D volumes was performed in Plane A (the reference plane: four-chamber view) alone. Tomographic ultrasound imaging (TUI) was added to the display of each diagnostic plane. The left ventricular outflow plane (Cardiac plane 1: five-chamber view, aorta), the right ventricular outflow plane (Cardiac plane 2: pulmonary artery) and the abdominal circumference plane (Cardiac plane 3: abdominal circumference, stomach) were retrieved by the software from the 3D volumes and the data were analyzed to determine whether Cardiac planes 1-3 were displayed correctly in each volume. RESULTS: The automated software displayed, in at least one TUI plane, target Cardiac plane 1 in 94.4% of volumes, target Cardiac plane 2 in 91.7% of volumes and target Cardiac plane 3 in 97.2% of volumes. CONCLUSION: Our results validate the concept of automated sonography and its potential clinical applicability.     

Tomographic ultrasound imaging of the fetal heart: a new technique for identifying normal and abnormal cardiac anatomy.

OBJECTIVE: In 2003 and 2004, the American College of Radiology, the American Institute of Ultrasound in Medicine, and the American College of Obstetricians and Gynecologists published guidelines for the standard ultrasound examination of the fetus. Each group recommended that the outflow tracts of the fetal heart be examined if technically feasible. One method to accomplish this task is to perform a free-hand sweep of the transducer beam directed in a transverse plane from the 4-chamber view to the fetal neck. One problem with this approach is that the examiner may not direct the beam transversely and, therefore, may not accurately identify the outflow tract anatomy. METHODS: A new technology, tomographic ultrasound imaging (TUI), allows the examiner to obtain a volume data set that simultaneously displays multiple images at specific distances from the 4-chamber view. This study examined TUI technology for identifying normal and abnormal fetal cardiac anatomy with the use of either static or spatiotemporal image correlation volume data sets. RESULTS: The 4 views used in the screening examination of the outflow tracts of the fetal heart (4-chamber, 5-chamber, 3-vessel, and tracheal views) could be identified with the use of TUI technology in fetuses between 13 and 40 weeks' gestation. Examples of fetuses with abnormal cardiac anatomy of the outflow tracts (tetralogy of Fallot, transposition of the great vessels, and pulmonary stenosis) all showed abnormal anatomy on TUI. CONCLUSIONS: Tomographic ultrasound imaging technology enables the fetal examiner to evaluate the 4-chamber view and the outflow tracts in a systematic manner to identify normal and abnormal cardiac anatomy.     

Echocardiography in early pregnancy: review of literature.

OBJECTIVE: First-trimester transvaginal sonography is a widely used technique to examine the fetus early in pregnancy. The aim of this review was to explore the possibilities of examining the fetal heart at this early stage of pregnancy. METHODS: With the use of a computerized database (PubMed, US National Library of Medicine, Bethesda, MD), articles on first-trimester echocardiography were retrieved. Furthermore, the cited references of the studied articles were used to find additional articles. RESULTS: In the analyzed articles, an increase in visualization rates of the 4-chamber view and the outflow tracts was shown in the last decade, with visualization rates of greater than 90% at 13 weeks' gestation. The different cardiac defects that are shown in first-trimester fetuses are mainly defects involving the 4-chamber view, indicating that defects solely affecting the outflow tracts are difficult to diagnose in the first trimester of pregnancy. The sonographic assessment of the fetal heart between 14 and 18 weeks' gestation has been described. The literature, however, has not shown clear advantages of performing fetal echocardiography during this period compared with transvaginal sonography at 13 weeks' gestation. CONCLUSIONS: First-trimester echocardiography is a promising technique, which can be of considerable value for patients at risk of having offspring with cardiac defects. This technique is, however, currently limited to a few specialized centers.     

Application of automated sonography on 4-dimensional volumes of fetuses with transposition of the great arteries

OBJECTIVE: The purpose of this study was to assess, in second-trimester fetuses with transposition of the great arteries (TGA), the performance of software (sonographically based volume computer-aided analysis) that automatically retrieves diagnostic cardiac planes from a 4-dimensional volume of the fetal chest obtained with spatiotemporal image correlation. METHODS: We retrospectively evaluated the 4-dimensional spatiotemporal image correlation volumes of 12 fetuses with TGA (complete TGA, 10 cases; correct TGA, 2 cases). The data were analyzed to determine whether the target diagnostic planes, that is, cardiac plane 1 (left ventricle outflow tract) and cardiac plane 2 (right ventricle outflow tract), were correctly identified in at least 1 of the 7 automatically generated tomographic sonographic image displays and whether they allowed diagnosis of TGA. RESULTS: In 9 of 10 fetuses with complete TGA, target diagnostic cardiac plane 1 showed a branching arterial vessel (pulmonary artery) arising from the left ventricle, whereas in 7 of 10 fetuses, the aorta arising from the right ventricle was shown. In both cases with correct TGA, the pulmonary artery starting from the morphologic left ventricle was shown, whereas in 1 of 2, the connection of the aorta with the morphologic right ventricle was found. In all of the fetuses with TGA, a ventricular arterial connection anomaly was shown in either cardiac plane 1 or 2. CONCLUSIONS: This automatic approach shows good retrieval of diagnostic cardiac planes in fetuses with TGA, which may improve diagnostic efficacy for this disease.     

自动四维彩色容积超声在胎儿心脏检查中的应用

目的 探讨自动四维彩色容积超声在正常胎儿心脏检查中的应用价值.方法 对120例孕中期(18～23孕周)胎儿心脏进行四维容积扫查,在显示四腔心切面、启动彩色多普勒后采集胎儿胸部容积数据,利用超声自动多平面成像法自动获取3个诊断切面,分别为切面1(左心室流出道切面)、切面2(右心室流出道切面)及切面3(动脉导管弓切面),并采用超声断层显像法(TUI)显示所有切面的彩色血流图.对所有的容积数据进行分析并确定在每个容积数据中切面1～3是否正确显示.结果 通过自动四维彩色容积超声扫描,切面1～3的显示率分别为100%、96.67%、91.67%.切面1至少可在连续3个TUI图像上可靠显示,切面2和切面3均至少可在连续2个TUI图像上可靠显示.结论 自动四维彩色容积超声可自动获取胎儿心脏检查中所需的重要切面,显示率较高,并可观察相应切面的血流情况,显示效果良好.     

First‐Trimester Assessment of the Nasal Bones Using the Retronasal Triangle View

Objective. The purpose of this study was to evaluate a new sonographic technique for identifying the nasal bones using the retronasal triangle view, ie, the coronal plane at which the palate and frontal processes of the maxilla are simultaneously visualized. Methods. Three‐dimensional (3D) volumes were acquired from women undergoing first‐trimester sonographic screening for aneuploidy by 2 accredited operators. Those data sets in which the fetal face was clearly identified were selected for offline analysis by 2 other observers who were unaware of the sonographic or clinical findings. The nasal bones were classified as both present, only 1 present (right or left), or absent according to the presence or absence of 2 small paired echogenic linear structures at the upper tip of the retronasal triangle as determined by 3D navigation in the coronal plane and compared to those findings obtained by 3D navigation in the sagittal plane. Additional 3D data sets involving a subset of 4 first‐trimester fetuses with trisomy 21 and absent nasal bones were also analyzed retrospectively and included randomly in the study group. Results. A total of 110 3D data sets were analyzed, of which 86% were obtained transabdominally and 14% transvaginally. The quality of nasal bone identification was classified subjectively by the observers as good in 67% of cases, fair in 29%, and poor in 4%. The nasal bones were classified as at least 1 present in 106 of the cases (96%) and absent in 4 (4%), with complete agreement between observers in both the sagittal and coronal planes (κ = 1). Discrimination between the right and left nasal bones was possible in 89% and 93% for observer A and in 96% and 96% for observer B by assessing the sagittal and coronal views, respectively (right nasal bone: κ = 0.90 [95% confidence interval (CI), 0.79–1]; left nasal bone: κ = 0.85 [95% CI, 0.60–0.99]). The nasal bones were not identified at the level of the retronasal triangle view in any of the fetuses with trisomy 21 and absent nasal bones. Conclusions. This study shows that the nasal bones can be confidently identified as paired echogenic structures located at the upper tip of the retronasal triangle. This coronal view of the fetal face offers the possibility of screening for the presence or absence of the nasal bones in the first trimester, especially when the standard midsagittal views of the fetal face are suboptimal because of fetal or maternal factors. Because both nasal bones can be evaluated simultaneously in the coronal plane, the retronasal triangle view may be advantageous over the conventional midsagittal view assessment, in which only 1 of the 2 nasal bones is evaluated.     

Feasibility of Automated 3‐Dimensional Fetal Cardiac Screening in Routine Ultrasound Practice

Objective. The purpose of this study was to prospectively assess the clinical feasibility of an automated 3‐dimensional (3D) software tool for extended basic cardiac screening in routine ultrasound practice. Methods. During the 2‐month study period, all gravidas fitting our inclusion criteria were consecutively included. Cardiac 3D volumes were acquired within the time slot allocated for the usual 2‐dimensional fetal examination. All volumes were assessed on their quality, based on display of the 4‐chamber view, and on the ability to sufficiently display diagnostic cardiac planes (left ventricular outflow tract [LVOT], right ventricle outflow tract [RVOT], and stomach location) with Sonography‐Based Volume Computer‐Aided Diagnosis software (SonoVCAD; GE Healthcare, Milwaukee, WI). Results. Volume acquisition was successful in 107 of 126 cases (85%). For each sonographer, more than 70% of the acquired cardiac volumes were of high or sufficient quality. Separately analyzed, diagnostic planes of the LVOT, RVOT, and stomach location were visible in 62.1%, 81.6%, and 92.2%, respectively. An extended basic fetal cardiac examination based on retrieval of all diagnostic cardiac planes from a single volume using SonoVCAD could be performed in 46.6% of the cases. Conclusions. This study shows that cardiac volume acquisition can be incorporated in a routine ultrasound screening program without much difficulty. However, currently, SonoVCAD software still lacks the consistency to be clinically feasible for cardiac screening purposes. Further advances in ultrasound technology and familiarization with 3D ultrasound might improve its performance.     

中孕期胎儿超声筛查切面的规范化探讨

目的探讨在中孕期胎儿筛查中规范超声检查的重要性及操作程序。方法根据临床工作中的体会，应用9个标准切面进行中孕期胎儿筛查，即小脑横径切面，唇面部冠状切面，脊柱纵切面，心脏四腔心切面，左右室流出道长轴切面，双肾横切面，左右侧脐动脉起始段彩色血流，双上肢及双下肢切面。结果对2111例中孕期妇女进行超声筛查，检出211例胎儿异常，其中严重畸形胎儿83例，包括颅脑、中枢神经系统畸形22例，心脏畸形14例，唇腭裂13例，消化系统畸形8例，胎儿水肿综合征6例，单脐动脉13例，肢体畸形2例，泌尿系统畸形1例，膈疝1例，肺分离征1例，骶尾部肿块1例，右下腹肿块1例。超声检查结果与病理解剖相符。结论中孕期胎儿超声筛查切面的规范化是早期发现异常胎儿，减少漏诊的重要措施，对减少围产期死亡率，提高出生人口质量具有重要意义。     

正常成年人上腔静脉的二维超声检测

目的探讨上腔静脉(SVC)最佳超声检测途径,获取较客观的SVC形态学指标。方法对随机选取的56例健康志愿者行经右锁骨上窝及心尖五腔、剑下四腔切面基础上的SVC超声探查,测量平静呼吸状态下各切面SVC内径及可见长度。结果56例受试者右锁骨上窝、胸骨旁心尖五腔及剑下四腔切面SVC显示率分别是,96.43%、89.3%、82.1%,显示长度分别是(56.49±7.91)mm、(28.29±5.83)mm、(22.05±4.37)mm。吸气相内径分别是(16.00±2.11)mm、(13.71±2.34)mm、(11.43±2.05)mm,呼气相内径分别是(9.41±1.63)mm、(8.91±1.78)mm、(6.61±1.14)mm。结论右锁骨上窝切面及心尖五腔切面SVC显示满意率较高,可对SVC行全程检测。SVC内径随呼吸周期呈规律性变化。     

First‐Trimester Assessment of the Fetal Palate

We describe a new technique that can facilitate the first‐trimester examination of the fetal palate using the Volume NT algorithm (Samsung Medison, Seoul, Korea), a program that automatically detects the exact midsagittal plane of the head and is primarily designed for semiautomatic measurement of the nuchal translucency thickness. Three‐dimensional (3D) data sets from the fetal face were captured with Volume NT and subsequently reformatted with the Oblique View software to obtain orthogonal views of the primary and secondary palate in coronal and axial planes, respectively. By testing this method in selected 3D data sets obtained retrospectively (n = 12) and prospectively (n = 28), we were able to extract clinically acceptable views of the fetal palate in all cases. This preliminary report shows that with this new 3D automation development, early evaluation of the fetal palate is feasible and reproducible and could be easily incorporated into the first‐trimester sonographic protocol once its ability to detect abnormal cases is demonstrated.     

Role of tomographic ultrasound imaging with spatiotemporal image correlation for identifying fetal ventricular septal defects

OBJECTIVE: The purpose of this study was to test the possibility of diagnosing ventricular septal defects (VSDs) by using tomographic ultrasound imaging (TUI) on 4-dimensional volumes of the fetal chest obtained with spatiotemporal image correlation and the color Doppler function. METHODS: We retrospectively evaluated the 4-dimensional spatiotemporal image correlation volumes of 8 fetuses with VSDs (single in 7 and double in 1) between 20 and 33 weeks' gestation. The data were analyzed to determine whether VSDs were correctly identified in at least 1 of 7 automatically generated TUI displays. RESULTS: All of the included VSDs were correctly identified with the use of an interslice distance in the TUI function ranging from 0.8 to 2 mm without the need to further manipulate the volume. CONCLUSIONS: This automatic approach shows good retrieval of diagnostic cardiac planes in fetuses with VSDs, which may improve the diagnostic accuracy for this disease.     

A novel algorithm for comprehensive fetal echocardiography using 4-dimensional ultrasonography and tomographic imaging.

OBJECTIVE: Tomographic ultrasound imaging (TUI) is a new display modality that allows simultaneous visualization of up to 8 parallel anatomic planes. This study was designed to determine the role of a novel algorithm combining spatiotemporal image correlation and TUI to visualize standard fetal echocardiographic planes. METHODS: Volume data sets from fetuses with and without congenital heart defects (CHDs) were examined with a novel algorithm that allows simultaneous visualization of the 3-vessel and trachea view, the 4-chamber view, and outflow tracts. Visualization rates for these planes as well as the ductal arch and 5-chamber view were calculated. RESULTS: (1) Two hundred twenty-seven volume data sets from fetuses without (n = 138) and with (n = 14) CHDs were reviewed; (2) among fetuses without CHDs, the 4-chamber view, 5-chamber view, ductal arch, 3-vessel and trachea view, left outflow tract, and short axis of the aorta were visualized in 99% (193/195), 96.9% (189/195), 98.5% (192/195), 88.2% (172/195), 93.3% (182/195), and 87.2% (170/195) of the volume data sets, respectively; (3) these views were visualized in 85% (17/20), 80% (16/20), 65% (13/20), 55% (11/20), 55% (11/20), and 70% (14/20) of the volume data sets, respectively, from fetuses with CHDs; and (4) simultaneous visualization of the short axis of the aorta, 3-vessel and trachea view, left outflow tract, and 4-chamber view was obtained in 78% (152/195) of the volume data sets from fetuses without CHDs and in 40% (8/20) of those with CHDs. CONCLUSIONS: The 3-vessel and trachea view, the 4-chamber view, and both outflow tracts can be simultaneously visualized using a novel algorithm combining spatiotemporal image correlation and TUI.     

The use of the minimum projection mode in 4-dimensional examination of the fetal heart with spatiotemporal image correlation.

OBJECTIVE: The minimum projection mode (MPM) is a rendering algorithm available in some 3- and 4-dimensional ultrasonography systems that, in 1 image, allows the visualization of vessels and cystic anatomic structures located in different scanning planes. The objective of this study was to compare the information displayed in images obtained with the MPM with their corresponding 2-dimensional ultrasonographic images from fetuses with and without structural heart defects. METHODS: Thirty-two volume data sets acquired with the spatiotemporal image correlation technique from fetuses with (n = 15) and without (n = 17) structural heart defects were analyzed. Rendered images of the upper abdomen, 4-chamber view, and 3-vessel view were compared with the corresponding 2-dimensional images. Two independent observers with experience in fetal echocardiography reviewed these volume data sets using the MPM. The visualization rate of specific anatomic structures seen from a transverse sweep of the heart was recorded for each observer, and the interobserver agreement was assessed by statistical indices of agreement (kappa statistic). RESULTS: Images obtained by the MPM displayed more vascular structures than those of corresponding 2-dimensional images at the level of the 3-vessel view. For conotruncal anomalies, the minimum mode projected the aorta and pulmonary arteries in 1 single plane, facilitating the understanding of their spatial relationships. The interobserver agreement score was moderate to "almost perfect" for assessment of most anatomic structures in the upper abdomen, 4-chamber view, and 3-vessel view sections. However, interobserver agreement ranged from fair to poor for visualization of the left outflow tract, atrial septum, and flap of the foramen ovale. CONCLUSIONS: The MPM is an alternative rendering modality that facilitates visualization of normal and abnormal vascular connections to the fetal heart at the level of the 3-vessel view. This technique may be useful in prenatal diagnosis of conotruncal anomalies and in assessment of the spatial relationships of abnormal vascular connections in the upper mediastinum.     

Fetal intracardiac echogenic foci: visualization depends on the orientation of the 4-chamber view.

OBJECTIVE: To compare the frequency of visualization of echogenic intracardiac foci in different cardiac views. METHODS: Women having ultrasonographic examinations between October 1997 and July 1998 were prospectively evaluated if a fetal echogenic intracardiac focus was seen in either ventricle. RESULTS: Echogenic intracardiac foci were seen in 89 fetuses in whom both the apical and lateral 4-chamber heart views were obtained. Eight-six fetuses (97%) had a single focus (83 in the left ventricle and 3 in the right ventricle), and 3 (3%) had 2 foci. Echogenic intracardiac foci were seen in the apical 4-chamber view in 89 (100%) and in the lateral 4-chamber view in only 26 (29%; P = .001). CONCLUSIONS: Echogenic intracardiac foci are not easily seen in the lateral 4-chamber view. Studies that suggest an increased risk of aneuploidy when echogenic foci are seen should specify the orientation of the 4-chamber view used.     

产前超声筛选胎儿中晚期心脏病的临床研究

目的探讨四腔心观（FCV）加三血管-气管观（3VT）在胎儿中晚期心脏病产前超声筛选中的临床意义。方法应用Sequoia512彩色多普勒超声诊断仪，检查孕18～40周胎儿共3211例，与尸体解剖证实和产后超声追踪对照，比较单纯FCV、FCV加左、右室流出道观（FCV＋VOTV）、FCV加大动脉短轴观（FCV＋SAV）、FCV＋3VT筛选胎儿中晚期心脏畸形的敏感性。结果FCV筛选胎儿心脏病的敏感性为54％（91／169），FCV＋VOTV的敏感性为70％（118／169），FCV＋SAV的敏感性为66％（112／169）；FCV＋3VT的敏感性为85％（143／169），明显高于前三者（P〈0、05）。结论FCV＋3VT可以明显提高筛选技术的敏感性，缩短检查时间，可以作为筛选妊娠中晚期胎儿心脏病的首选方法。     

二维超声技术对胎儿腭部显示切面的探讨

目的总结中孕期及晚孕期胎儿腭部超声声像图特征。方法选取孕21～36周产前二维超声和产后检查证实腭部声像正常的1885例胎儿（中孕组1023例,晚孕组862例）的超声图像进行分析。检查中采用经胎儿颌下、口裂、耳前连续区域显示腭冠状切面,经口裂显示腭纵切面,连续完整显示胎儿正常腭部并统计显示率。结果产前超声经胎儿颌下、口裂至耳前区域腭冠状切面扫查两组胎儿正常硬腭显示为横带状强回声,正常软腭显示为横带状低回声;中孕组、晚孕组胎儿腭部超声显示率分别为76％（777／1023）、53％（458／862）;经口裂腭纵切面扫查胎儿正常腭部显示为连续弧形带状回声：中孕组、晚孕组胎儿腭部超声显示率分别为49％（501／1023）、13％（113／862）。冠状切面与纵切面联合扫查中孕组胎儿腭部超声显示率为94％（961／1023）,晚孕组胎儿腭部超声显示率为56％（483／862）。结论中孕期胎儿存在明显的下颌骨软骨间隙,经胎儿颌下、口裂、耳前区域腭冠状切面及经口裂腭纵切面扫查不受胎头屈曲位置影响,二维超声可较完整显示胎儿腭部声像,有助于检出单纯性继发腭裂。但由于成像过程依赖于操作者的技术和手法,尚不能作为常规筛查方法。     

Are maternal and sonographic factors associated with the detection of a fetal echogenic cardiac focus?

OBJECTIVE: To evaluate the influence of maternal weight and the orientation of the fetal 4-chamber heart view on the detection of a fetal echogenic cardiac focus. METHODS: In this nested case-control study, 103 women undergoing anatomic surveys at 15 to 22 weeks between January 1, 1997, and June 15, 1999, were identified as having an echogenic cardiac focus via our computerized database. A control group was selected from among the same group of patients. Data were collected from the sonography reports, prenatal records, and sonographic images of 4-chamber heart views; maternal characteristics and sonographic details were recorded, including the orientation of the 4-chamber view (apical, basilar, and right and left lateral). RESULTS: Gravidas in the echogenic cardiac focus group were more likely to be of lower weight (68.0 +/- 14.4 versus 72.9 +/- 18.3 kg; P = .04), of lower body mass index (25.5 +/- 5.3 versus 27.3 +/- 6.2 kg/m2; P = .03), of younger age (24.4 +/- 6.5 versus 26.9 +/- 6.9 years; P = .01), and African American or Asian (37.9% versus 27.2% and 9.7% versus 2%; P = .01). Cases were scanned at earlier gestational ages (18.9 +/- 1.6 versus 19.5 +/- 1.7 weeks; P = .01). The focus group was more likely to have had an apical view of the fetal heart taken (80.8% versus 51.4%; P = .0001). Controls were more likely to have had a right lateral view taken (44.6% versus 20.8%; P = .002). No significant difference was found between groups in terms of any other maternal or sonographic variable studied. CONCLUSIONS: The echogenic cardiac focus group was more likely to have a lower body mass index and to be scanned with the apical fetal heart view. The orientation of the fetal 4-chamber heart view exerted the most statistically significant influence on detection rates for the echogenic cardiac focus, implying that the more technically facile the sonographic study, the more likely an echogenic cardiac focus will be found.     

时间-空间相关成像技术对正常胎儿心脏大动脉空间角度的定量研究

目的 应用时间-空间相关成像(spatiotemporal image correlation,STIC)技术建立不同孕周胎儿心脏大动脉空间角度的正常参考值范围.方法 运用STIC采集352例孕20～38周正常胎儿的心脏三维数据,通过正交三平面模式测量标准四腔观与左室长轴观之间、左室长轴观与主肺动脉干观之间以及动脉导管弓观与主动脉弓观之间的角度.应用相关回归分析评价上述角度与孕周的相关性.结果 正常胎儿标准四腔观与左室长轴观的角度与孕周不相关(r=0.04,P=0.51),95%正常参考值范围为34.5°～56.7°.左室长轴观与主肺动脉干观之间以及动脉导管弓长轴观与主动脉弓长轴观之间的角度与孕周相关(r分别为-0.53、0.57,P＜0.001),回归方程分别为:Y=154-4.24X+0.05X2,Y=-20.8+2.65X-0.37X2.结论 STIC能定量测量20～38周胎儿心脏大动脉之间的角度并建立正常参考值范围,为产前筛查大动脉空间关系异常的先天性心脏病提供有价值的参考标准.

Abstract：

Objective To establish the reference ranges of the spatial angles among cardiac chambers and great vessels in second and third trimester fetuses measured by spatiotemporal image correlation (STIC).Methods Volume images of 352 normal fetuses from 20 to 38 weeks of gestation were recruited in the study.An off-line analysis of acquired volume datasets was carried out with multiplanar mode.Parameters measured included angles between:(1) the 4-chamber view and the left ventricular long axis view; (2) the left ventricular long axis view and main pulmonary artery; and (3) the ductal arch and aortic arch.The relationships between above-mentioned angles and gestational age were assessed by correlation and regression analysis.Results The angle between the 4-chamber view and the left ventricular long axis view (range:55.7° - 35.7°,mean:45.7° ± 5.12°) was uncorrelated with gestational age (r = 0.03,P = 0.51).In contrast,the angle between the left ventricular long axis view and main pulmonary artery,and the angle between the ductal arch and aortic arch were correlated with gestational age (P ＜ 0.001),and the correlation coefficient was - 0.53 and 0.57 respectively.The best-fit exponential curve regression equations of the angle between the left ventricular long axis view and main pulmonary artery was:Y = 154- 4.24X +0.05X2 ,and the angle between the ductal arch and aortic arch was:Y = - 20.8 + 2.65X - 0.37X2.Conclusions The angles among cardiac chambers and great arteries of fetuses from 20 to 38 weeks of gestation can be quantitatively measured by STIC.The reference ranges provide a reliable quantitative standard to estimate the spatial relationships of the cardiac large arteries of fetuses,which may be clinically useful in prenatal screening congenital heart disease.     

Application of three-dimensional ultrasonography in the evaluation of the fetal heart.

The objectives of this study were to determine whether three-dimensional ultrasonography can provide more cardiac views than two-dimensional ultrasonography and to develop a standard technique. Eighteen women, 16 to 26 weeks' gestation, were scanned with two-dimensional ultrasonography for 10 minutes or less to obtain fetal heart views. Three-dimensional ultrasonography was used (< or =10 minutes) to obtain up to 4 acquisitions of the fetal heart: 4-chamber view, left parasagittal, transverse, and longitudinal nonstandard. Views were later extracted from saved volume data, comparing the yields of two- and three-dimensional ultrasonography. The 4-chamber view was obtained in 15 (93%) of 16 cases on both two- and three-dimensional ultrasonography. On two-dimensional ultrasonography, the left outflow tract was obtained in 68% of the cases; on three-dimensional ultrasonography, the left outflow tract was obtained in 46% from the 4-chamber view acquisition and in 100% from the left parasagittal acquisition. On two-dimensional ultrasonography, the right outflow tract was obtained in 68% of the cases; on three-dimensional ultrasonography, the right outflow tract was obtained in 86% from the 4-chamber view acquisition and in 71% from the left parasagittal acquisition. Aortic and ductal arches were obtained in 12% and 18%, respectively, on two-dimensional ultrasonography. On three-dimensional ultrasonography the aortic and ductal arches were obtained in 66% and 86%, respectively, from the 4-chamber view acquisition and in 57% and 71%, respectively, from the left parasagittal acquisition. Three-dimensional ultrasonography permitted a greater number of cardiac views to be extracted from volume data than did two-dimensional ultrasonography.     

Potential pitfalls and methods of improving in utero diagnosis of transposition of the great arteries, including the baby bird's beak image.

OBJECTIVE: The goal of this study was to analyze our recent experience with fetuses with transposition of the great arteries (TGA) to identify potential pitfalls and possible methods to better detect conotruncal anomalies such as TGA. METHODS: We analyzed all nonreferral obstetric ultrasound examinations in which we performed basic, targeted, or formal fetal echocardiography with a newborn diagnosis of TGA. RESULTS: Nine neonates had TGA. Five of these cases were diagnosed prenatally, and 4 of these had complex congenital heart abnormalities. In these 4 cases, there were abnormalities in the cardiac axis (n = 3), abnormal valves or ventricular size (n = 2), and ventricular septal defects (n = 3) that were detected on the 4-chamber view of the heart. In all cases that were not detected prenatally, both prospective and retrospective reviews of the 4-chamber heart appeared normal. The prospective analyses of the outflow tracts were all interpreted as normal, whereas the retrospective review showed subtle abnormalities such as the "baby bird's beak" image. In review of these cases, there was failure to show the "crisscross" relationship of the outflow tracts. In 1 case, 5 short axis views of the heart, retrospectively showed the artery originating from the left ventricle and bifurcated, representing the pulmonary artery. CONCLUSIONS: Transposition of the great arteries may be associated with complex cardiac disease that could be detected on the 4-chamber view of the heart. When the 4-chamber view is normal, it is important to identify the crisscross relationship of the outflow tracts. If this is not done, it is important to document that the pulmonary artery bifurcates and originates from the right ventricle. Five short axis views of the heart may be helpful to detect conotruncal abnormalities.