Defining 4D Ventricular Mechanics in Acquired and Congenital Heart Disease

描述（由申请人提供）：快速采用积极治疗心力衰竭，包括再同步起搏，重新引起了人们对左心室基本机电特性的兴趣。与MRI相关，这导致了旨在开发和应用评估左心室力学方法的研究努力，包括磁共振组织标记，相速度心肌作图和3D空间中的cine DENSE位移作图。相比之下，研究右心室力学的努力较少，即使在某些情况下，如先天性心脏病、肺动脉高压和肺心病，右室功能可能比左室功能更重要。在超声心动图中，组织多普勒应变率方法的发展，现在已经有了新的斑点跟踪方法，能够显示多种类型的应变变形，而不依赖于角度，包括周向缩短应变，收缩期径向增厚应变，扭转和解扭转应变。二维方法可以在一定程度上定义横断面视图中的节段运动，但却与贯穿平面的运动相结合。对于超声和MRI，可能需要一个强大的3D方法来全面定义区域心室壁运动和变形。该提案旨在开发和验证一种方法，以获得在先进的3D超声心动图系统上进行的超声扫描的左心室和右心室变形图的空间密集位移场；一种能够显示两个心室的应变位移场和扭转变形的方法。该建议旨在进一步发展我们开创的技术，并在独特的动态心脏幻影和开胸猪中验证它们，使用声速测量作为金标准。我们还将通过研究先天性心脏病患者来评估我们新方法的有效性，并将其转化为临床环境，并比较我们的方法MRI标记和壁速度编码应变测量的结果。

DESCRIPTION (provided by applicant): The rapid adoption of aggressive treatments for heart failure, including resynchronization pacing, has renewed interest in the fundamental electromechanical properties of the left ventricle. Related to MRI, this has resulted in research efforts aimed at the development and application of methods to assess left ventricular mechanics, including magnetic resonance tissue tagging, phase velocity myocardial mapping and cine DENSE displacement mapping in 3D space. By comparison, there have been fewer efforts to study right ventricular mechanics, even though in certain conditions such as congenital heart diseases, pulmonary hypertension and cor pulmonale, RV function can be more important than LV function. In echocardiography, the development of tissue Doppler strain rate methods have been by now followed by newer speckle tracking methods capable of showing multiple types of strain deformation without angle dependency, including circumferential shortening strain, radial thickening strain in systole and twisting and untwisting. Two-dimensional methods can define, to some extent, segmental motion in cross-sectional views, but are compounded by through-plane motion. For both echo and MRI, it will likely require a robust 3D method to comprehensively define regional ventricular wall motion and deformation. This proposal is aimed at development and validation of a method to obtain spatially-dense displacement fields of both left and right ventricular deformation maps from ultrasound scans performed on an advanced 3D echocardiographic system; a method that should be capable of showing strain displacement fields and torsional deformation for both ventricles. This proposal is aimed at further developing the techniques we have pioneered and validating them in a unique dynamic cardiac phantom and in open-chest pigs using sonomicrometry as a gold standard. We will also evaluate the efficacy of our new approach and translate it to the clinical setting by studying patients with congenital heart disease and compare our results from our method MRI tagging, and wall velocity encoded strain measurements. PUBLIC HEALTH RELEVANCE: Much interest exists in Cardiology in the recently developed 4D ultrasound technologies for imaging the heart. We believe that as informative as these dynamic qualitative anatomical diagnostic images are, the quantitative aspects of these 4D methods for defining cardiac mechanics are likely more important. The spatially-dense 4D speckle tracking method which we have developed and hope to further refine and test in this proposal could provide a method for study of the dynamic biventricular function of the heart, which could, in turn, improve therapeutic approaches to treatment of heart disease.