Prenatal Diagnosis Of Congenital Anomalies

在美国，先天畸形是继早产之后导致围产儿死亡的第二大原因。成像技术的进步使超声能够在宫内检测许多解剖缺陷。该项目的目标是提高胎儿疾病和先天畸形的诊断和治疗水平。围产期研究处发起了一系列项目，以改进先天性异常的检测，并使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.应用时空图像相关技术(STIC)进行胎儿心脏的四维超声检查：本分会介绍了一种新的胎儿心脏检查技术。使用一种新的心脏门控技术获取胎儿心脏的体积数据集，该技术使用自动的胸壁前壁横向和纵向扫描。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，比较了来自正常胎儿的两个有代表性的体积与来自患有以下先天性心脏畸形的胎儿的体积：房室间隔缺损、三尖瓣狭窄、三尖瓣闭锁和下腔静脉中断伴异常静脉引流。使用横向扫描获得的体积数据集来显示心脏解剖结构。利用一个参考点在四腔切面上导航，可以在三个正交平面上同时研究心脏内部结构。除了主动脉弓和导管弓外，还可以交互操作体积来同时显示两个流出道。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，可以用来检查四室观和流出区。这一新的方法学可能有助于胎儿心脏解剖的评估。此外，该处还介绍了彩色多普勒STIC的使用情况。彩色多普勒STIC可以多平面显示室间隔缺损、三尖瓣返流的多平面显示和容积显示、彩色和能量多普勒超声显示流出道的容积显示(包括正常和双进右室双出口的病例)，以及显示卵圆孔水平的静脉血流。这项技术有可能简化流出道的可视化，并改进对室间隔缺陷位置和范围的评估。其他应用包括对卵圆孔水平的反流和静脉流进行三维评估。 2.观察者之间的一致性和从用时空图像相关(STIC)获取的四维(4D)体积数据集显示左、右室流出道的标准心脏视图的技术的重复性：开发了一种从用STIC获取的体积数据集获得左室流出道(LVOT)和右室流出道(RVOT)的动态多平面图像的技术。体积数据来自心脏解剖正常的胎儿。一名研究人员预先选择了20个质量令人满意的体积数据集。这些数据由两名有胎儿超声心动图经验的独立观察者随机分配进行盲法审查。每个胎儿只使用一个体积数据集。训练结束后，观察者获得了标准的LVOT和RVOT心脏切面，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=优秀)进行了1到5分的评分。计算每一种观点的中位数分数和四分位数范围，以及观察者间和观察者内的一致性。第1组和第2组的LVOT图像的中位数(四分位数范围)分别为3.5(2.25-5.00)和4(3.00-5.00)。第一和第二观察者获得的RVOT图像的中位数(四分位数范围)分别为3(3.00-5.00)和3(2.00-4.00)。观察者间组内相关系数分别为0.693(95%可信区间0.380~0.822)和0.696(95%可信区间0.382~0.866)。在观察者内部一致性分析中，观察者1在第二次分析容量时给予左心室流出道的分数较高[左心室流出道：3.5(2.25-5.00)比5.00(4.00-5.00，p=0.008)]。因此，STIC可以由独立的检查者重复性地用于评估胎儿心脏流出道。观察者内可变性试验期间稍好的图像质量评级分数表明，需要对操作员进行培训，以操纵和分析STIC获得的体积数据。

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.