High-resolution in vivo and non-invasive imaging of myocardial fibers

描述(申请人提供)：在美国，每四例死亡中就有一例是由心脏病引起的。心脏病是男性和女性以及包括非裔美国人、西班牙裔美国人和白人在内的大多数种族的主要死亡原因。除了常见的预防措施外，发现心脏异常的早期迹象是预防心脏病死亡的关键。虽然我们有一系列非侵入性的核磁共振技术来检测大脑异常，但心脏成像技术仍然不发达，而且往往不够充分。特别是，在活体内成像和跟踪心肌纤维即使不是完全不可能，也是极其具有挑战性的。心肌纤维从心底到心尖形成独特的螺旋。这种结构是决定心肌机械和电学性质的关键因素。虽然扩散张量成像(DTI)一直是唯一一种能够无创地标测心肌纤维的技术，但它主要是在体外应用。活体人体心脏的DTI仅在有限的几个研究中进行。目前还没有临床公认的成像和跟踪心肌纤维的技术。这项应用的目的是开发和验证一种基于磁化率张量成像(STI)和纤维束成像技术的全新的在体心肌纤维成像方法。STI测量磁场和心肌之间的相互作用。它利用这种相互作用来量化组织特性和重建纤维结构。该技术具有快速、高分辨率、无创、定量等特点。如果成功，STI将允许对 心肌的微观结构和连通性具有较高的空间细节。它将填补我们在评估健康和患病心脏的心肌状况方面的一个重大空白。

DESCRIPTION (provided by applicant): One in every four deaths in the US is caused by heart disease. Heart disease is the leading cause of death for both men and women and for people of most ethnicities including African Americans, Hispanics and Whites. Besides common preventive measures, detecting early signs of cardiac abnormalities is the key for preventing death caused by heart disease. While we have a range of non-invasive MRI techniques to detect brain abnormalities, techniques for imaging the heart are still underdeveloped and often inadequate. In particular, it has been extremely challenging, if not entirely impossible, to image and track myocardial fibers in vivo. Myocardial fiber forms a unique helical spiral from base to apex of the heart. This structure is a key determinant of the mechanical and electric properties of the myocardium. While diffusion tensor imaging (DTI) has been the only technique that allows the mapping of myocardial fibers non-invasively, it has been applied primarily ex vivo. In vivo DTI of live human hearts has been only performed in a limited few studies. There are currently no clinically accepted techniques for imaging and tracking the myocardial fibers. The objective of this application is to develop and validate a radically new way to image myocardial fibers in vivo based on the technique of susceptibility tensor imaging (STI) and tractography. STI measures the interaction between magnetic fields and myocardium. It utilizes this interaction to quantify tissue property and reconstruct fiber structures. The proposed technique is fast, high resolution, non-invasive and quantitative. If successful, STI will allow the routine examination of the microstructure and connectivity of myocardium with high spatial details. It will fill in a majo gap in our capability to evaluate the myocardial conditions of both healthy and diseased hearts.