Model-Based Design of Wall Motion Measures for 4-Dimensional Cardiac Imaging

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)能够在短短几秒钟的成像时间内获得整个心脏周期内完整的心脏三维图像，从而激发了心脏病专家的想象力。这种全四维(3D加时间)心脏图像中包含的丰富信息可以极大地提高临床诊断能力，但到目前为止，临床医生仍然很难获得这些信息。这项建议的目标是提供一套实用的方法，从这些大型数据集中提取信息，将其缩减为定量的、对诊断有用的措施，并以简单、直接的方式呈现这些信息，所有这些都在与临床实践的时间要求一致的时间范围内。这一目标的实现将首次释放4D心脏成像的真正诊断能力。特别是，这项建议将重点放在4D心脏成像最适合解决的一个常见问题上：筛查表明存在冠状动脉疾病的急性缺血区(血流不足)。这项建议的具体目的是：(1)检验这样的假设，即减少的三维缩短分数(3DFS)预测实验诱导的急性缺血区的大小和位置的准确性高于专家心脏科医生目前的技术水平；(2)测试在多巴酚丁胺负荷期间减少的三维缩短分数(3DFS)以比专家心脏病专家分析更高的准确性检测和定位经血管造影证实的冠状动脉疾病区域的假设；(3)测试来自单一手动数字化帧的光学血流跟踪以类似于完全手动数字化的精度为完整的心内膜周期提供心内膜表面数据的假设；以及(4)使用基于模型的过程来开发新的定制的4D室壁运动测量方法，以改进对急性缺血区的大小、位置和严重程度的量化。这项拟议工作的意义在于，它将提供迄今为止开发的最准确、劳动强度最低的室壁运动测量方法，最终允许临床医生常规测量室壁运动，而不是简单地进行定性评估。

DESCRIPTION (provided by applicant): Technology for imaging the heart has advanced dramatically in recent years. In particular, real-time three-dimensional ultrasound (RT3D) 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 wealth of information contained in such fully four-dimensional (3D plus time) cardiac images could greatly enhance clinical diagnosis, but so far it remains largely inaccessible to clinicians. The goal of this proposal is to provide a set of practical methods for extracting information from these large datasets, reducing it to quantitative, diagnostically useful measures, and presenting this information in a simple, straightforward way, all within a time frame consistent with the time demands of clinical practice. Achievement of this goal will unleash for the first time the true diagnostic power of 4D cardiac imaging. In particular, this proposal will focus on a common problem for which 4D cardiac imaging is ideally suited: screening for regions of acute ischemia (insufficient blood flow) that indicate the presence of coronary artery disease. The specific aims of this proposal are: (1) to test the hypothesis that reduced three-dimensional fractional shortening (3DFS) predicts the size and location of experimentally induced acutely ischemic regions with better accuracy than the current state of the art, segment scoring by expert cardiologists; (2) to test the hypothesis that reduced three-dimensional fractional shortening (3DFS) during dobutamine stress detects and localizes regions of angiographically confirmed coronary artery disease with better accuracy than analysis by expert cardiologists; (3) to test the hypothesis that optical flow tracking from a single manually digitized frame provides endocardial surface data for the full cardiac cycle with similar accuracy to fully manual digitizing; and (4) to use a model-based process to develop new customized 4D wall motion measures to improve quantification of the size, location, and severity of acutely ischemic regions. The significance of the proposed work is that it will provide the most accurate, least labor-intensive measures of ventricular wall motion developed to date, finally allowing clinicians to routinely measure wall motion, rather than simply assessing it qualitatively.