Defining 4D Ventricular Mechanics in Acquired and Congenital Heart Disease

描述(由申请人提供)：心力衰竭的积极治疗，包括再同步起搏的迅速采用，重新引起了人们对左心室基本机电特性的兴趣。与MRI相关的是，这导致了旨在开发和应用评估左心室力学的方法的研究努力，包括磁共振组织标记、相速度心肌标测和3D空间电影密度位移标测。相比之下，对右室力学的研究较少，尽管在某些情况下，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，随着组织多普勒应变率方法的发展，新的散斑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以及扭转和解扭。二维方法可以在一定程度上定义横断面图中的节段性运动，但会被贯穿平面的运动所复合。对于ECHO和MRI，可能都需要一个稳健的3D方法来全面定义局部室壁运动和变形。这项建议旨在开发和验证一种方法，从先进的三维超声心动图系统上进行超声扫描，获得左、右室变形图的空间密集位移场；该方法应该能够显示两个室的应变位移场和扭转变形。这项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体模和以声波显微测量为金标准的开胸猪身上验证它们。我们还将评估我们的新方法的有效性，并通过研究先天性心脏病患者将其转化为临床环境，并比较我们的方法MRI标记和室壁速度编码应变测量的结果。 公共卫生相关性：最近开发的用于心脏成像的4D超声技术对心脏病学有很大的兴趣。我们认为，尽管这些动态定性解剖诊断图像信息丰富，但这些用于定义心脏力学的4D方法的定量方面可能更重要。我们已经开发的空间密集的4D斑点跟踪方法，并希望在这项提议中进一步完善和测试，可以为研究心脏的动态双室功能提供一种方法，这反过来可以改进心脏病的治疗方法。

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.