Clinical validation of cardiac strain measures with real-time 4D ultrasound

描述（由申请人提供）：近年来，心脏成像技术取得了显著进展。特别是，实时三维超声（RT 3D或4D）已经捕获了心脏病专家的想象力，其能够在短短几秒钟的成像中获得整个心动周期内心脏的完整三维图像。这些四维（3D +时间）数据序列中包含的复杂的心壁运动和时间信息具有极大地增强心脏临床诊断的潜力。然而，大多数心脏检查中心仍然依赖于2D超声心动图，而4D心脏成像中的时间信息往往被忽视。该提案的目标是利用4D超声中包含的丰富信息。特别是，该提案将重点关注4D心脏成像非常适合的常见问题：直接从4D超声测量应变和心脏扭转。本提案的目的是：（1）量化4D超声上光流的位移和应变误差，并与植入犬心脏的声显微测量法获得的结果进行比较;（2）检验4D超声上光流在健康志愿者身上具有临床等效结果的假设与通过基于MRI的方法获得的应变的类似测量相比，对心脏（正常心脏）和患病心脏的应变进行比较;（3）测试4D超声上的光流在性能方面优于现有的基于2D的应变估计方法的假设。我们的方法的设计是基于光流跟踪心肌运动的4D超声。可以从估计的3D +时间运动场自动导出方向位移和应变以及心脏扭转。在目标1和2中，将测量比位移、应变和扭转，并与定量评价研究中的“金标准”进行比较。在目标3中，我们将广泛比较4D方法和2D方法在广泛的临床超声心动图患者数据集中估计应变测量的性能。一旦完成，为什么以及何时最好地使用4D而不是2D测量的问题将得到定量回答。 公共卫生相关性：所提出的工作的意义在于，它将提供一种新颖有效的三维应变和扭转测量工具，使临床医生能够定期定量和实时测量室壁运动。此外，这项研究将为心脏病专家提供改进的糖尿病心肌病（和不同步）筛查测试，以帮助他们确定那些可能需要更具侵入性和昂贵的程序的患者，例如可以安全地避免此类测试的患者的心脏导管插入术。

DESCRIPTION (provided by applicant): Technology for imaging the heart has advanced dramatically in recent years. In particular, real-time three-dimensional ultrasound (RT3D or 4D) has captured the imagination of cardiologists with its ability to obtain complete three-dimensional images of the heart over an entire cardiac cycle in just a few seconds of imaging. The complex cardiac wall motion and temporal information contained in these four-dimensional (3D + time) data sequences has the potential to greatly enhance clinical diagnoses of the heart. However, most cardiac examination centers still depend on 2D echocardiography, and the temporal information in the 4D cardiac imaging is often overlooked. The goal of this proposal is to utilize the wealth of information contained in 4D ultrasound. In particular, this proposal will focus on a common problem for which 4D cardiac imaging is ideally suited: measuring strain and cardiac torsion directly from 4D ultrasound. The aims of this proposal are: (1) Quantify errors of displacement and strain from optical flow on 4D ultrasound with respect to results obtained by sonomicrometry implanted in dog hearts; (2) Test the hypothesis that optical flow on 4D ultrasound can have clinically equivalent results on healthy volunteers (normal hearts) and diseased hearts compared to similar measures of strain obtained by MRI based methods; (3) Test the hypothesis that optical flow on 4D ultrasound has specific advantages in terms of performance over existing 2D based methods of strain estimation. The design of our method is based on optical flow to track myocardial motion in 4D ultrasound. Directional displacements and strains and cardiac torsion can be automatically derived from the 3D + time motion field estimated. In aims 1 and 2, specific displacements, strains, and torsion will be measured and compared to "gold standards" in quantitative evaluation studies. In aim 3, we will extensively compare the performance of 4D methods and 2D methods in estimating strain measures across a wide range of clinical echocardiography patient data sets. Once completed, the questions of why and when to best use 4D rather then 2D measures will be answered quantitatively. PUBLIC HEALTH RELEVANCE: The significance of the proposed work is that it will provide a novel and effective 3D strain and torsion measuring tool, allowing clinicians to routinely measure wall motion quantitatively and in real-time. In addition this research will provide cardiologists with improved screening tests for diabetic cardiomyopathy (and dyssynchrony) to help them determine those patients that may require more invasive and costly procedures such as heart catheterization from patients that can be safely spared such tests.