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

描述（由申请人提供）：近年来，心脏成像技术取得了巨大进步。特别是，实时三维超声（RT3D）能够在几秒钟的成像时间内获得整个心脏周期的完整三维图像，这引起了心脏病学家的想象。这种全四维（3D加时间）心脏图像所包含的丰富信息可以极大地增强临床诊断，但到目前为止，临床医生在很大程度上仍然无法获得这些信息。本提案的目标是提供一套实用的方法，用于从这些大型数据集中提取信息，将其减少到定量的，诊断有用的度量，并以简单，直接的方式呈现这些信息，所有这些信息都在符合临床实践时间要求的时间框架内。这一目标的实现将首次释放出4D心脏成像的真正诊断能力。特别地，本提案将关注一个常见的问题，4D心脏成像非常适合：筛选急性缺血（血流不足）区域，表明冠状动脉疾病的存在。本提案的具体目的是：(1)验证减少三维分数缩短（3DFS）预测实验诱导的急性缺血区域的大小和位置的假设，其准确性优于目前心脏病专家的分段评分；(2)验证多巴酚丁胺应激下三维分数缩短（3DFS）检测和定位血管造影证实的冠状动脉疾病区域的准确性优于心脏病专家分析的假设；(3)验证单个手工数字化框架的光流跟踪提供全心周期的心内膜表面数据的假设，其精度与完全手工数字化相似；(4)使用基于模型的流程开发新的定制4D壁运动测量，以提高对急性缺血区域的大小、位置和严重程度的量化。这项工作的意义在于，它将提供迄今为止最准确、最省力的心室壁运动测量方法，最终使临床医生能够常规测量心室壁运动，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.