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

描述(由申请人提供)：近年来，心脏成像技术有了很大的进步。特别是，实时三维超声(RT3D或4D)凭借其在短短几秒钟的成像中获得整个心脏周期的完整三维图像的能力，激发了心脏病专家的想象力。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有可能极大地提高心脏的临床诊断能力。然而，大多数心脏检查中心仍然依赖于二维超声心动图，而4D心脏成像中的时间信息往往被忽视。这项提议的目标是利用4D超声波所包含的丰富信息。特别是，这项建议将集中在4D心脏成像最适合的一个常见问题上：直接从4D超声测量应变和心脏扭转。该建议的目的是：(1)相对于植入犬心脏的声学显微测量结果，量化4D超声上光流的位移和应变误差；(2)检验4D超声上的光流与通过基于MRI的方法获得的类似应变测量结果相比，在临床上可对健康志愿者(正常心脏)和患病心脏具有同等结果的假设；(3)测试4D超声上的光流在性能方面与现有基于2D的应变估计方法相比具有特定优势的假设。我们设计的方法是基于光流来跟踪4D超声中的心肌运动。可以从估计的3D时间运动场自动得出定向位移和应变以及心脏扭转。在目标1和目标2中，将测量特定的位移、应变和扭转，并将其与定量评估研究中的“黄金标准”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上估计应变测量的性能。一旦完成，为什么以及何时最好使用4D而不是2D措施的问题将得到定量回答。 与公共健康相关：这项拟议工作的意义在于，它将提供一种新颖有效的3D应变和扭转测量工具，使临床医生能够常规地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，以帮助他们确定哪些患者可能需要更具侵入性和更昂贵的手术，例如患者的心导管置入术，这些患者可以安全地避免此类测试。

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.