时间-空间相关成像技术评价胎儿心脏形态结构的初步研究

目的评估3D／4D时间-空间相关成像（STIC）是否能比常规二维胎儿超声心动图提供更多胎儿心脏的切面及信息。方法采用3D／4DSTIC超声系统对26例孕龄16～41周的正常胎儿进行心脏和胸部的自动扫查，获得容积数据后进行脱机分析，主要对胎儿心脏的解剖结构进行多平面的观察和三维重建，重点观察胎儿心脏的流出道等结构。结果26例胎儿皆成功获得满意二维和三维四腔心切面的图像。通过STIC技术获得的容积数据显示了一系列相互垂直的三维平面图像（即A平面、B平面、C平面），对其中的每一幅图像都可通过旋转、平移进行控制、分析。切割或三维重建图像可获得比常规二维胎儿超声心动图检查更多的切面及信息。结论3D／4DSTIC技术比常规二维胎儿超声心动图检查能更快地提供更多的观察心脏解剖结构的切面和信息。     

Real-time three-dimensional fetal echocardiography: initial feasibility study.

Real-time three-dimensional echocardiography acquires data as a volume rather than as a series of planar images, thereby obviating cardiac or respiratory gating and limiting artifacts generated by random motion. This study was undertaken to evaluate the feasibility of using real-time three-dimensional echocardiography to evaluate fetal cardiac anatomy and function. Ten human fetuses were evaluated in utero, four of whom had congenital heart disease. Freehand transabdominal scanning was performed on each pregnant woman using a real-time three-dimensional echocardiography system. Four volume clips at 20 volumes/s of duration 1.5 s each were obtained on each fetal heart and stored for off-line analysis. Data were displayed immediately as a series of four simultaneous planes, with the ability for the observer to manipulate the position of each plane within the acquired volume data set. Cardiac motion could be slowed, stopped, or viewed at its original speed. Most structures and views, as well as cardiac function, could be visualized consistently. Abnormal structures could be detected readily. Off-line analysis was rapid and easy. We conclude that fetal real-time three-dimensional echocardiography is a feasible, facile, and rapid new technique.     

Three-dimensional echocardiographic evaluation of fetal heart anatomy and function: acquisition,analysis, and display.

The purpose of this work was to assess the functional dynamics and anatomy of the cardiac chambers and great vessels in the fetus (18 to 36 weeks) using in utero three-dimensional ultrasonographic imaging. Fifteen patients were studied using conventional two-dimensional sonographic equipment incorporating a position sensor attached to the transducer and a graphics workstation. Sonographic image data were acquired at 30 images per second and required less than 30 seconds per data set. Fetal heart rate and time in the cardiac cycle were determined and used to synchronize image data for reprojection into a volume at the appropriate part of the cardiac cycle. Volume data were analyzed, rendered, and displayed interactively. Three-dimensional sonographic volume data demonstrated fetal cardiac anatomy from multiple orientations and showed the myocardium, valves, ventricles, and atria clearly. The images showed good correlation with currently available embryologic-anatomic-pathologic data. Dynamic and spatial relationships among chambers, valves, and great vessels were readily appreciated. Three-dimensional sonographic imaging of the fetal heart provides both anatomic and functional information regarding the valves, myocardium, great vessels, and chamber dynamics. Interactive three-dimensional cinegraphic display enhances visualization of cardiac anatomy, which can be difficult to appreciate with two-dimensional methods. The methods presented in this work demonstrate the feasibility of three-dimensional fetal echocardiography.     

Three-dimensional quantitative echocardiographic assessment of ventricular volume in healthy human fetuses and in fetuses with congenital heart disease.

The purpose of this study was to evaluate the feasibility of three-dimensional freehand echocardiographic assessment of ventricular volumetry in healthy fetuses and in fetuses with congenital heart disease. The study was approved by the hospital institutional review board. After echocardiographic examination by conventional ultrasonographic equipment interfaced with a magnetic tracking system, three-dimensional cardiac data were collected prospectively in 57 fetuses. Ventricular volumes were determined from three-dimensional data sets, and 22 fetuses with congenital heart disease were compared with 29 healthy fetuses. A multiple regression analysis of covariance was performed to assess between-group differences. Gated three-dimensional volume data sets enabled assessment of ventricular volumes in 51 of the 57 fetuses. Both fetuses with and without congenital heart disease had exponential increases in cardiac volumes during gestation. In fetuses with congenital heart disease and a marked inequality of ventricular size but no heart failure, the combined end-diastolic and stroke volumes of both ventricles were found to be significantly reduced compared with controls with no disease and fetuses with other types of congenital heart disease. Three-dimensional imaging can provide estimates of ventricular volume changes in fetal hearts with abnormal ventricular morphology that cannot easily be performed by two-dimensional echocardiography, and it may provide insight into evolving congenital heart disease.     

Three-dimensional (3D) echocardiographic analysis of congenital heart disease in the fetus: comparison with cross-sectional (2D) fetal echocardiography.

OBJECTIVE: We attempted to assess the ability of Doppler-gated three-dimensional (3D) fetal echocardiography to reconstruct and display specific cardiac structures in fetuses with cardiac anomalies and to determine whether any advantage is offered by 3D sonographic cardiac examination over conventional fetal echocardiography. DESIGN: After 2D fetal echocardiographic examination, 3D cardiac data were collected prospectively in 22 fetuses with various congenital heart defects. Their ages ranged from 19 to 35 weeks' gestation. Basic echocardiographic key views of the venoatrial, atrioventricular and ventriculoarterial connections were derived from volume data sets and selected for 3D reconstruction and analysis. Comparisons were made with 2D echocardiographic imaging of the fetal hearts and the diagnostic image quality of visualized structural details was evaluated. RESULTS: The underlying cardiac malformation was well or satisfactorily visualized in 20 fetuses using 2D imaging. Gated 3D volume data sets enabled diagnostically acceptable visualization of all affected cardiac structures in 7 of 22 fetuses. High-quality 3D reconstruction of the site and spatial orientation of ventricular septal defects was obtained in 9 of 13 patients. Two-dimensional imaging remained the principal diagnostic modality in all cases with additional structural detail being obtained by 3D imaging in only two fetuses. CONCLUSIONS: Three-dimensional imaging of fetal heart disease is feasible for a wide range of lesions, and may provide additional information of clinical value in a small number of cases when compared with 2D imaging.     

Three-dimensional ultrasonography of the fetal distal lower extremity: normal and abnormal.

The objective of this study was to compare two-dimensional and three-dimensional ultrasonographic evaluation of fetal distal lower extremities. Data from two-dimensional and three-dimensional ultrasonographic examinations from 40 distal lower extremities in 33 fetuses from a predominantly high-risk patient population were compared. Three-dimensional ultrasonography routinely provided three orthogonal planes (coronal, sagittal, and axial) for distal lower extremity evaluation. Specific features of distal lower extremity evaluation were not different using two-dimensional and three-dimensional ultrasonography. Rotation of the rendered volume provided assistance in assessing all but one of 40 distal lower extremities. Time from image acquisition to assessment for two views (coronal and sagittal) was longer with three-dimensional ultrasonography (8.2 min) than with two-dimensional ultrasonography (3.2 min). Confidence in the diagnosis of abnormal distal lower extremities was slightly improved using three-dimensional ultrasonography compared to two-dimensional ultrasonography. Pregnancy management was assisted in three of the four cases with isolated limb anomalies. In conclusion, three-dimensional ultrasonography improves the ability to evaluate the fetal distal lower extremity because of the multiplanar nature of volume assessment and the ability to rotate volume data sets. In addition, it provides assistance in counseling families, particularly for cases involving isolated limb anomalies.     

Four-Dimensional Echocardiography with Spatiotemporal Image Correlation and Inversion Mode for Detection of Congenital Heart Disease

The aim of this study was to evaluate the use of 4-D echocardiography with inversion mode and spatiotemporal image correlation (IM-STIC) in the detection of normal and abnormal fetal hearts. We retrospectively studied 112 normal fetuses and 16 fetuses with a confirmed diagnosis of congenital heart disease. Two volumes were acquired from each of the fetuses using transverse and sagittal sweeps. Volumes were reconstructed with IM-STIC. In normal fetuses, IM-STIC facilitated visualization of the interior structures of the fetal heart and great vessels. The visualization rates of intended planes obtained from IM-STIC 4D data ranged from 55% to 100%. In 16 fetuses with congenital heart disease, IM-STIC was able to display the cardiac malformations using digital casting. Some of the malformations were suspected during pre-natal 2-D echocardiography, and their pre-natal IM-STIC diagnoses were confirmed by post-natal echocardiography, surgery and/or autopsy. Hence, 4-D IM-STIC allows better visualization of complex congenital heart disease and should be considered a very useful addition to 2-D echocardiography.     

Three-dimensional (3-D) ultrasonography for obtaining the four and five-chamber view: comparison with cross-sectional (2-D) fetal sonographic screening.

OBJECTIVES: To assess the ability of Doppler-gated 3-D fetal echocardiography to reconstruct and display specific cardiac structures routinely visualized during antenatal ultrasound in a population at low risk for cardiac anomalies. To determine whether any advantage is offered by 3-D sonographic cardiac examination over conventional sonographic fetal screening techniques. DESIGN: After routine two-dimensional sonographic examination, 3-D cardiac data were collected prospectively in 30 fetuses with gestational ages between 19 and 23 weeks from a low risk patient population. Basic echocardiographic key views were derived from 3-D data and selected for reconstruction and analysis. Four- and five-chamber views were rated and only those views judged to be well visualized were considered as positive results. RESULTS: The four- and five-chamber views were well visualized in all but one fetus using conventional 2-D imaging. Gated 3-D volume data sets enabled visualization of these structures in only 19 of 30 fetuses but provided additional structural depth and allowed a dynamic 3-D perspective of valvar morphology and ventricular wall motion. The right ventricular outflow tract was available from the 3-D volumes in 16 subjects. CONCLUSIONS: Considering the versatility of gated 3-D fetal cardiac imaging we believe that it may soon become an important component of fetal screening thus helping to retrieve standard cardiac cross sections when 2-D imaging is limited by lack of sonographer experience or sonographic windows. Diagnostically acceptable echocardiographic views were obtained more consistently with 2-D ultrasound than with 3-D volume data.     

Three- and four-dimensional freehand fetal echocardiography: a feasibility study using a hand-held Doppler probe for cardiac gating.

OBJECTIVE: To evaluate the clinical feasibility of the signal from a hand-held Doppler probe as a real-time tracking signal for dynamic three-dimensional (3D) (so-called four-dimensional (4D)) fetal echocardiography in a random patient cohort. METHODS: Seventy fetuses, with and without congenital heart disease, at various gestational ages (mean, 25 weeks; range, 18-38 weeks) were investigated using freehand 3D echocardiography. Time gating was achieved concurrently by obtaining a Doppler signal of the fetal heart without further signal averaging. In 10 fetuses, Doppler gating was compared to cardiotocogram (CTG)-gated 3D echo using signal averaging. Gray-scale and color Doppler dynamic 3D displays and multiplanar views were assessed according to their ability to accurately depict cardiac gating and cardiac morphology. RESULTS: In 68/70 fetuses, valid Doppler-based trigger signals were obtained. Correct cardiac gating was achieved in 231/275 (84%) 4D datasets. Doppler tracing of the fetal heart allowed beat-to-beat triggering without the necessity for signal averaging. Doppler gating detected rapid changes in the fetal heart rate more reliably than CTG gating, but was more sensitive to acoustic interference between the gating and echo-transducer when color-coded Doppler imaging was used. Image quality was highly dependent on random motion and the acoustic window. A total of 171/231 (74%) correctly gated datasets successfully demonstrated clinically useful 4D images of the fetal heart. The reconstruction of 3D and multiplanar views provided additional views not obtainable by two-dimensional imaging. CONCLUSION: These results show that a hand-held Doppler probe can be used as a reliable online gating source for 4D fetal echocardiography. Copyright 2005 ISUOG     

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.     

Dynamic three-dimensional transesophageal echocardiography using a computed tomographic imaging probe — clinical potential and limitation

Dynamic three-dimensional echocardiography is a new diagnostic tool for spatial visualisation of cardiac anatomy and volumetric assessment. A computer-controlled probe acquires parallel tomographic slices, from which dynamic three-dimensional images of the heart can be reconstructed. Thirty adult patients with valvular heart diseases, congenital heart diseases, intracardiac masses, heart failure and other cardiac lesions, underwent conventional two-dimensional (n=30), three-dimensional echocardiography (n=30) and thermodilution (n=17). The feasibility, usefulness and possibility of simulating a surgical view of intracardiac anatomy and exact volumetry were determined. The two different morphologic images were compared qualitatively. For quantitative analysis volumetry was performed using standard thermodilution technique and dynamic three-dimensional echocardiography. In more than 80% of the patients additional morphologic information was gained and a strong correlation (r=0.75–0.95) between two volumetry assessments was found. Based on this findings, dynamic three-dimensional echocardiography is an additional and valuable approach in the perioperative and intensive care management in this group of patients.     

Real-time 3-dimensional fetal echocardiography with an instantaneous volume-rendered display: early description and pictorial essay.

OBJECTIVE: Random fetal motion, rapid fetal heart rates, and cumbersome processing algorithms have limited reconstructive approaches to 3-dimensional fetal cardiac imaging. Given the recent development of real-time, instantaneous volume-rendered sonographic displays of volume data, we sought to apply this technology to fetal cardiac imaging. METHODS: We obtained 1 to 6 volume data sets on each of 30 fetal hearts referred for formal fetal echocardiography. Each volume data set was acquired over 2 to 8 seconds and stored on the system's hard drive. Rendered images were subsequently processed to optimize translucency, smoothing, and orientation and cropped to reveal "surgeon's eye views" of clinically relevant anatomic structures. Qualitative comparison was made with conventional fetal echocardiography for each subject. RESULTS: Volume-rendered displays identified all major abnormalities but failed to identify small ventricular septal defects in 2 patients. Important planes and views not visualized during the actual scans were generated with minimal processing of rendered image displays. Volume-rendered displays tended to have slightly inferior image quality compared with conventional 2-dimensional images. CONCLUSIONS: Real-time 3-dimensional echocardiography with instantaneous volume-rendered displays of the fetal heart represents a new approach to fetal cardiac imaging with tremendous clinical potential.     

二维超声"三切面"法筛查胎儿先天性心脏畸形

目的 探讨应用二维超声"三切面"法筛查胎儿先天性心脏畸形的可行性及局限性. 方法 以四腔心、左心室、右心室流出道为筛查切面,筛查胎儿先天性心脏畸形.疑有异常者送上级医院行系统超声心动图检查,并追踪随访,与引产后尸检或出生后超声心动图对照. 结果 本法筛查获得较清晰的胎儿心脏二维结构图像.12 046例受检胎儿中,正确诊断胎儿心脏异常19例,误诊1例,漏诊2例,产前诊断符合率86.36%. 结论 应用二维超声采用四腔心加左右心室流出道切面法检查可清楚直观地观察胎儿心脏解剖结构,方法 简便可靠.     

Noninvasive diagnostics in congenital heart disease: echocardiography and magnetic resonance imaging

The ability to noninvasively diagnose even the most complex congenital heart disease is one of the greatest advances in the care of children with cardiac defects. Initially, two-dimensional echocardiography displayed anatomy; later, Doppler allowed the quantitation of pressure and flow. Using these modalities, cardiac catheterization is unnecessary for most children with cardiac defects. Echocardiography also is routinely used for intraoperative and fetal cardiac imaging. Three-dimensional magnetic resonance imaging can now quantitate volumes of irregular shaped heart chambers (eg, the right ventricle) and blood flow (eg, as from a leaking valve). As technology moves further into the digital age, developments will continue to facilitate noninvasive diagnosis and treatment of children with congenital heart disease.     

Prenatal screening for congenital heart disease using real-time three-dimensional echocardiography and a novel 'sweep volume' acquisition technique.

OBJECTIVES: Conventional prenatal screening for congenital heart disease (CHD) involves a time-consuming and highly operator-dependent acquisition of the four-chamber view and outflow tracts. By acquiring the entire fetal heart instantaneously as a single volume, real-time three-dimensional echocardiography (RT3DE) may facilitate fetal cardiac screening. METHODS: Four reviewers, each experienced with fetal cardiac imaging, blindly and independently evaluated a single cardiac volume from each of 18 fetuses (11 normal, seven with CHD). Two-dimensional echocardiography served as the gold standard. Three-dimensional evaluation of each fetus included a series of volume acquisitions lasting 2-6 s each. A 'sweep volume' technique was developed to fit larger hearts into a single non-gated volume. RESULTS: RT3DE had a high sensitivity for detecting CHD (93%), with only a single case being missed by two observers. Specificity for CHD was low (45%), with a high rate of 'cannot determine' responses and false positive artifacts. CONCLUSIONS: These preliminary results suggest that RT3DE has the potential to function as a screening tool for fetal heart disease. However, artifacts must be recognized and minimized, resolution must improve, and substantial training will be necessary prior to widespread clinical use.     

Tissue Doppler gated (TDOG) dynamic three-dimensional ultrasound imaging of the fetal heart.

Dynamic three-dimensional (3D) ultrasound imaging of the fetal heart is difficult due to the absence of an electrocardiogram (ECG) signal for synchronization between loops. In this study we introduce tissue Doppler gating (TDOG), a technique in which tissue Doppler data are used to calculate a gating signal. We have applied this cardiac gating method to dynamic 3D reconstructions of the heart of eight fetuses aged 20-24 weeks.The gating signal was derived from the amplitude and frequency contents of the tissue Doppler signal. We used this signal as a replacement for ECG in a 3D-volume reconstruction and visualization, utilizing techniques established in ECG-gated 3D echocardiography.The reliability of the TDOG signal for fetal cardiac cycle detection was experimentally investigated. Simultaneous recordings of tissue Doppler of the heart and continuous wave (CW) spectral Doppler of the umbilical artery (UA) were performed using two independent ultrasound systems, and the TDOG signal from one system was compared to the Doppler spectrum data from the other system. Each recording consisted of a two-dimensional (2D) sector scan, transabdominally and slowly tilted by the operator, covering the fetal heart over approximately 40 cardiac cycles. The total angle of the sweep was estimated by recording a separate loop through the center of the heart, in the elevation direction of the sweep.3D reconstruction and visualization were performed with the EchoPAC-3D software (GE Medical Systems). The 3D data were visualized by showing simultaneous cineloops of three 2D slices, as well as by volume projections running in cineloop.Synchronization of B-mode cineloops with the TDOG signal proved to be sufficiently accurate for reconstruction of high-quality dynamic 3D data. We show one example of a B-mode recording with a frame rate of 96 frames/s over 20 seconds. The reconstruction consists of 31 volumes, each with 49 tilted frames. With the fetal heart positioned 5-8 cm from the transducer, the sampling distances were approximately 0.15 mm in the beam direction, 0.33 degrees approximately 0.37 mm azimuth and 0.45 degrees approximately 0.51 mm elevation. From this single dataset we were able to generate a complete set of classical 2D views (such as four-chamber, three-vessel and short-axis views as well as those of the ascending aorta, aortic and ductal arches and inferior and superior venae cavae) with high image quality adequate for clinical use.     

胎儿实时三维(四维)超声心动图的初步临床应用

目的 以胎儿四腔心容积为基础,通过后处理,与二维超声比较,探讨胎儿四维超声心动图在显示正常胎儿心脏和先天性心脏畸形胎儿中的临床应用。方法 对108例孕妇行胎儿心脏四维超声检查,其中84例心脏正常、24例先天心脏畸形。显示胎儿四腔心切面后启动四维容积扫查获得心脏灰阶容积和彩色多普勒血流容积,将图像储存后进行后处理。获取容积与后处理由同一医师完成。利用上述容积显示如下结构：四腔心（4C）、左心室流出道（LVOT）、右心室流出道（RVOT）、三血管气管（3VT）、二尖瓣（MV）、三尖瓣（TV）、主动脉（AO）、肺动脉（MPA）、主动脉弓（ARCH）、动脉导管（DA）。比较正常胎儿孕周≥28周和<28周胎儿在不同四腔心初始位置下对同一结构显示率的差异。所有四维超声心动图的诊断结果与二维超声比较,其中11例先天心脏畸形经产后解剖或生后超声心动图证实。结果 108例胎儿均获得心脏四维容积数据（100%）。每个对象扫查时间（7.53±2.37）min,5 s/容积。四腔心与房室瓣显示率100%。除主动脉弓外,心脏正常胎儿孕周≥28周对上述心脏结构的显示率高于＜28周胎儿（P＜0.05）;除三血管气管切面外,心脏初始位置为心尖四腔心时对上述切面的显示率高于横位四腔心和心底四腔心（P＜0.05）。孕周与胎心初始位置对显示率有显著影响,孕周大、初始位置为心尖四腔心切面获取成功率较高。先天性心脏畸形胎儿24例,四维超声心动图在显示瓣膜、瓣环及心脏间隔上显示出优势。结论 以四腔心为基础切面能够快速获取胎儿心脏容积,并能较为完整地评价胎儿心脏结构。胎儿四维超声心动图在显示复杂胎儿心脏异常中起到一定的作用。     

Spatio-temporal image correlation (STIC): a new tool for the prenatal screening of congenital heart defects.

OBJECTIVE: To assess the feasibility and capability of STIC acquisition, performed by a general obstetrician performing antenatal ultrasound, to visualize fetal cardiac structures in women undergoing routine obstetric ultrasound examination, in order to obtain information to confirm normality of the fetal heart during intrauterine life. METHODS: This was a prospective study of one hundred fetuses with echocardiographically confirmed normal hearts and no extracardiac anomalies with gestational ages ranging between 18 and 37 weeks. A general obstetrician was invited to acquire the STIC volumes. The four-chamber view was obtained as a starting point. A standard 7.5-s acquisition time and 30 degrees angle of acquisition were used and the resulting STIC was stored for later offline analysis by a fetal echocardiologist. For each patient, the stored STIC data were first evaluated by sweeping from the initial acquisition plane, in the caudal direction and then cranially, zooming, slowing or stopping the cardiac motion to visualize views and structures. If a structure or view was rated as inadequate or not identifiable, a multiplanar three-dimensional (3D) examination of the STIC volume was taken in order to try to visualize it adequately. The rates obtained using just the STIC sweeps were compared independently, and then the 3D multiplanar study was added. RESULTS: STIC acquisition was possible in all cases. The mean time required for STIC acquisition was 7.5 min. A complete cardiac examination according to the set criteria was achieved in 94.2% (95% confidence interval (CI), 90-99) of cases. We obtained a 94.2% success rate of visualizing different structures and views of the fetal heart using the STIC sweep alone (95% CI, 90-99) and 96.2% adding 3D multiplanar examination (95% CI, 92-100). CONCLUSION: STIC acquisition of the fetal heart is feasible with high success rates in visualization of the principal connections. The STIC data acquired by a general obstetrician can subsequently be used by a fetal echocardiologist for prenatal confirmation of normal cardiac structure or exclusion of major cardiac malformations.     

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.     

A systematic approach to the use of the multiplanar display in evaluation of abnormal vascular connections to the fetal heart using 4-dimensional ultrasonography.

OBJECTIVE: The multiplanar display is a modality that allows the simultaneous visualization of 3 orthogonal planes from volume data sets obtained with 3- and 4-dimensional ultrasonography. Simultaneous display of standard views used in fetal echocardiography and their orthogonal planes may provide novel ultrasonographic views for examination of the fetal heart and its vascular connections. This study was designed to determine the clinical utility of the multiplanar display in the examination of abnormal vascular connections to the fetal heart. METHODS: We reviewed 4-dimensional volume data sets, acquired with the spatiotemporal image correlation technique, from patients with abnormal vascular connections to the fetal heart. Multiplanar views of the fetal heart were used to simultaneously display standard planes used in fetal echocardiography and their corresponding orthogonal planes. RESULTS: This study included 4 volume data sets from fetuses with confirmed abnormal vascular connections to the heart, including: (1) an interrupted inferior vena cava with azygos or hemiazygos vein continuation; (2) a persistent left superior vena cava draining into a dilated coronary sinus; and (3) a dilated superior vena cava associated with a thoracic lymphangioma. Simultaneous visualization of orthogonal planes displaying abnormal vascular connections to the fetal heart facilitated identification of the abnormal vessels and their spatial relationships with other vascular structures. CONCLUSIONS: Multiplanar imaging can be used to assess abnormal vascular connections to the fetal heart and may provide novel ultrasonographic planes for fetal echocardiography using 3- and 4-dimensional ultrasonography.