Prenatal Diagnosis Of Congenital Anomalies

在美国，先天性畸形是仅次于早产的围产期死亡的第二大原因。成像技术的进步使得超声能够在子宫内检测许多解剖缺陷。该项目的目标是改进胎儿疾病和先天性异常的诊断和治疗。围产期研究分支已启动了一系列项目，以改进先天性异常的检测，并利用三维超声评估胎儿的生长和发育。今年的调查结果包括： 1.使用时空图像相关（STIC）的胎儿心脏四维超声检查：分支描述了一种检查胎儿心脏的新技术。胎儿心脏的体积数据集是用一种新的心脏门控技术采集的，该技术使用自动的前胸壁横向和纵向扫描。这些体积来自69个胎儿：35个正常，16个先天性异常不影响心血管系统，18个心脏异常。对心脏结构进行动态多平面切片和表面绘制。为了说明STIC技术，将来自正常胎儿的两个代表性体积与从具有以下先天性心脏异常的胎儿获得的体积进行比较：房室间隔缺损、三尖瓣狭窄、三尖瓣闭锁和下腔静脉中断伴静脉引流异常。通过横向扫描获得的体积数据集用于显示心脏解剖结构。使用参考点导航四腔视图，可以在三个正交平面上同时研究心内结构。除了主动脉弓和导管弓之外，还可以交互式地操纵MRI以同时可视化两个流出道。生成了特定结构的新视图。利用STIC技术对胎儿心脏进行动态多平面切片和表面绘制是可行的。从横向扫描获得的一个高质量的体积数据集可用于检查四腔视图和流出道。这种新的方法可能有助于胎儿心脏解剖的评价。此外，分支描述了彩色多普勒STIC的使用。彩色多普勒STIC允许室间隔缺损的多平面可视化，三尖瓣反流的多平面显示和容积再现，通过彩色和能量多普勒超声检查流出道的容积再现（在正常情况下和双入口右心室双出口右心室的情况下），以及卵圆孔水平的静脉流的可视化。这项技术有可能简化流出道的可视化，并改善室间隔缺损的位置和程度的评价。其他应用包括在卵圆孔水平的反流射流和静脉流的三维评价。 2.观察者之间的一致性和技术的再现性，以显示从四维（4D）容积数据集采集的时空图像相关（STIC）的左心室和右心室流出道的标准心脏视图：开发了一种技术，以获得动态多平面图像的左心室流出道（LVOT）和右心室流出道（RVOT）从容积数据集采集的STIC。体积数据集采集自心脏解剖正常的胎儿。由一名研究者预先选择20个质量令人满意的体积数据集。由两名具有胎儿超声心动图经验的独立观察员随机分配数据进行盲态审查。每个胎儿仅使用一个体积数据集。培训后，观察员获得LVOT和RVOT的标准化心脏视图，根据诊断价值和图像质量（1 =不可接受，2 =边缘，3 =可接受，4 =良好，5 =极好），以1至5分的量表进行评分。计算每个视图的中位评分和四分位距，以及观察者间和观察者内的一致性。由第一名和第二名观察员获得的LVOT图像的中位评分（四分位距）分别为3.5（2.25-5.00）和4（3.00 - 5.00）。第一名和第二名观察员获得的RVOT图像的中位评分（四分位距）分别为3（3.00 - 5.00）和3（2.00 - 4.00）。LVOT的观察者间组内相关系数为0.693（95% CI 0.380 - 0.822），RVOT的观察者间组内相关系数为0.696（95% CI 0.382 - 0.866）。对于观察者内一致性分析，观察者1在第二次分析容积时给出的LVOT评分较高[LVOT：3.50（2.25 - 5.00）vs. 5.00（4.00 - 5.00，p=0.008）]。因此，STIC可重复用于评估胎儿心脏流出道的独立检查。在观察者内变异性试验期间，图像质量评分略好，这表明需要对操作员进行STIC获得的体积数据的操作和分析培训。

Congenital anomalies are the second leading cause of perinatal mortality in the United States after premature birth. Advances in imaging techniques have allowed the in utero detection of many anatomical defects with ultrasound. The goal of this project is to improve the diagnosis and treatment of fetal disease and congenital anomalies. The Perinatology Research Branch has initiated a series of projects to improve the detection of congenital anomalies and assess fetal growth and development with the use of three-dimensional ultrasound. The findings of this year include the following: 1. Four-dimensional ultrasonography of the fetal heart using Spatio-Temporal Image Correlation (STIC): The Branch described a new technique for the examination of the fetal heart. Volume datasets of the fetal heart were acquired with a new cardiac gating technique, which uses automated transverse and longitudinal sweeps of the anterior chest wall. These volumes were obtained from 69 fetuses: 35 normal, 16 with congenital anomalies not affecting the cardiovascular system, and 18 with cardiac abnormalities. Dynamic multiplanar slicing and surface rendering of cardiac structures were performed. To illustrate the STIC technique, two representative volumes from a normal fetus were compared with volumes obtained from fetuses with the following congenital heart anomalies: atrioventricular septal defect, tricuspid stenosis, tricuspid atresia, and interrupted inferior vena cava with abnormal venous drainage. Volume datasets obtained with a transverse sweep were used to demonstrate cardiac anatomy. Using a reference dot to navigate the four-chamber view, intra-cardiac structures could be simultaneously studied in three orthogonal planes. Volumes could be interactively manipulated to simultaneously visualize both outflow tracts, in addition to the aortic and ductal arches. Novel views of specific structures were generated. Dynamic multiplanar slicing and surface rendering of the fetal heart are feasible with STIC technology. One good quality volume dataset, obtained from a transverse sweep, can be used to examine the four-chamber view and the outflow tracts. This novel methodology may assist in the evaluation of fetal cardiac anatomy. Moreover, the Branch described the use of color Doppler STIC. Color Doppler STIC allowed multiplanar visualization of ventricular septal defects, multiplanar display and volume rendering of tricuspid regurgitation, volume rendering of the outflow tracts by color and power Doppler ultrasonography (both in a normal case and in a case of a double-inlet right ventricle with a double-outlet right ventricle), and visualization of venous streams at the level of the foramen ovale. This technique has the potential to simplify visualization of the outflow tracts and to improve the evaluation of the location and extent of ventricular septal defects. Other applications include 3-dimensional evaluation of regurgitation jets and venous streams at the level of the foramen ovale. 2. Agreement between observers and reproducibility of a technique to display standard cardiac views of the left and right ventricular outflow tracts from four-dimensional (4D) volume datasets acquired with Spatio-Temporal Image Correlation (STIC): A technique was developed to obtain dynamic multiplanar images of the left ventricular outflow tract (LVOT) and right ventricular outflow tract (RVOT) from volume datasets acquired with STIC. Volume datasets were acquired from fetuses with normal cardiac anatomy. Twenty volume datasets of satisfactory quality were pre-selected by one investigator. The data was randomly assigned for a blinded review by two independent observers with previous experience in fetal echocardiography. Only one volume dataset was used for each fetus. After a training session, the observers obtained standardized cardiac views of the LVOT and RVOT, which were scored on a scale of 1 to 5, based onn diagnostic value and image quality (1 = unacceptable, 2 = marginal, 3 = acceptable, 4 = good, and 5 = excellent). Median scores and interquartile range, as well as interobserver and intraobserver agreement were calculated for each view. Median scores (interquartile range) for LVOT images, obtained by the first and second observers, were 3.5 (2.25-5.00) and 4 (3.00 - 5.00), respectively. The median scores (interquartile range) for RVOT images obtained by the first and second observers were 3 (3.00 - 5.00) and 3 (2.00 - 4.00), respectively. The interobserver intraclass correlation coefficient for the LVOT was 0.693 (95% CI 0.380 - 0.822), and 0.696 (95% CI 0.382 - 0.866) for the RVOT. For the intraobserver agreement analysis, observer 1 gave higher scores to the LVOT the second time the volumes were analyzed [LVOT: 3.50 (2.25 - 5.00) vs. 5.00 (4.00 - 5.00, p=0.008)]. Therefore, STIC can be reproducibly used to evaluate fetal cardiac outflow tracts by independent examiners. Slightly better image quality rating scores during the intraobserver variability trial suggests the need for operator training for the manipulation and analysis of volume data obtained by STIC.