Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; Children's Clinic, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
J Am Soc Echocardiogr. 2020 Apr;33(4):493-503.e5. doi: 10.1016/j.echo.2019.11.003. Epub 2020 Jan 24.
Flow properties play an important role in cardiac function, remodeling, and morphogenesis but cannot be displayed in detail with today's echocardiographic techniques. The authors hypothesized that blood speckle-tracking (BST) could visualize and quantify flow patterns. The aim of this study was to determine the feasibility, accuracy, and potential clinical applications of BST in pediatric cardiology.
BST is based on high-frame rate ultrasound, using a combination of plane-wave imaging and parallel receive beamforming. Pattern-matching techniques are used to quantify blood speckle motion. Accuracy of BST velocity measurements was validated using a rotating phantom and by comparing BST-derived inflow velocities with pulsed-wave Doppler obtained in the left ventricles of healthy control subjects. To test clinical feasibility, 102 subjects (21 weeks to 11.5 years of age) were prospectively enrolled, including healthy fetuses (n = 4), healthy control subjects (n = 51), and patients with different cardiac diseases (n = 47).
The phantom data showed a good correlation (r = 0.95, with a tracking quality threshold of 0.4) between estimated BST velocities and reference velocities down to a depth of 8 cm. There was a good correlation (r = 0.76) between left ventricular inflow velocity measured using BST and pulsed-wave Doppler. BST displayed lower velocities (mean ± SD, 0.59 ± 0.14 vs 0.82 ± 0.21 m/sec for pulsed-wave Doppler). However, the velocity amplitude in BST increases with reduced smoothing. The clinical feasibility of BST was high, as flow patterns in the area of interest could be visualized in all but one case (>99%).
BST is highly feasible in fetal and pediatric echocardiography and provides a novel approach for visualizing blood flow patterns. BST provides accurate velocity measurements down to 8 cm, but compared with pulsed-wave Doppler, BST displays lower velocities. Studying blood flow properties may provide novel insights into the pathophysiology of pediatric heart disease and could become an important diagnostic tool.
血流性质在心脏功能、重构和形态发生中起着重要作用，但目前的超声心动图技术无法详细显示。作者假设血流斑点追踪（BST）可以可视化和量化血流模式。本研究旨在确定 BST 在儿科心脏病学中的可行性、准确性和潜在临床应用。
BST 基于高帧率超声，采用平面波成像和并行接收波束形成相结合。模式匹配技术用于量化血流斑点运动。通过使用旋转体模和将 BST 衍生的流入速度与健康对照受试者左心室获得的脉冲波多普勒进行比较，验证 BST 速度测量的准确性。为了测试临床可行性，前瞻性纳入了 102 名受试者（21 周到 11.5 岁），包括健康胎儿（n=4）、健康对照受试者（n=51）和不同心脏疾病患者（n=47）。
体模数据显示，在深度为 8cm 时，估计的 BST 速度与参考速度之间具有良好的相关性（r=0.95，跟踪质量阈值为 0.4）。BST 测量的左心室流入速度与脉冲波多普勒之间具有良好的相关性（r=0.76）。BST 显示的速度较低（平均±标准差，0.59±0.14m/s 与脉冲波多普勒的 0.82±0.21m/s）。然而，随着平滑度的降低，BST 中的速度幅度增加。BST 的临床可行性很高，因为在所有但一个病例（>99%）中都可以观察到感兴趣区域的血流模式。
BST 在胎儿和儿科超声心动图中具有高度可行性，为可视化血流模式提供了一种新方法。BST 可在 8cm 深度内提供准确的速度测量，但与脉冲波多普勒相比，BST 显示的速度较低。研究血流性质可能为儿科心脏病的病理生理学提供新的见解，并可能成为一种重要的诊断工具。
