Cardiac Diffusion Imaging for Heart Transplant Surveillance

用于心脏移植监测的心脏弥散成像

• 批准号: 8650639
• 负责人: ROLAND BAMMER
• 金额: $ 20.06万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-15 至 2016-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8650639
• 关键词: Abdomen; Acute; Acute Brain Injuries; Address; Algorithms; Allografting; American; Angiography; Arrhythmia; Biological; Biopsy; Blood flow; Brain; Cardiac; Cardiac Catheterization Procedures; Caring; Catheters; Chronic; Clinical; Complication; Contrast Media; Coronary Angiography; Coupled; Data; Development; Diffusion; Diffusion Magnetic Resonance Imaging; Diffusion weighted imaging; Early Diagnosis; Early treatment; Echo-Planar Imaging; Echocardiography; Future; Goals; Gold; Graft Rejection; Heart; Heart Transplantation; Heart failure; Image; Imaging Techniques; Injury; Kidney Failure; Left ventricular structure; Life; Magnetic Resonance Imaging; Maps; Measures; Methods; Molecular; Monitor; Morbidity - disease rate; Motion; Myocardial; Myocardial perfusion; Myocardial tissue; Myocardium; North America; Patients; Perforation; Perfusion; Physiological; Population; Process; Property; Protocols documentation; Protons; Reference Standards; Regional Perfusion; Research; Resolution; Resources; Risk; Role; Sampling; Signal Transduction; Site; Solutions; Stroke; Symptoms; Techniques; Testing; Time; Tissues; Transplant Recipients; Validation; Variant; Vascular Diseases; Ventricular septum; Vertebral column; Water; Weight; Work; allograft rejection; base; cardiovascular imaging; cost; flexibility; healthy volunteer; heart allograft; heart motion; improved; in vivo; innovation; novel; outcome forecast; prevent; public health relevance; reconstruction; tool; user-friendly; volunteer

PROJECT SUMMARY / ABSTRACT Diffusion weighted imaging (DWI) has an established role in detecting acute brain injury, most notably in the early detection of stroke. The application of cardiac diffusion- weighted MRI (cDWI) is similarly relevant for non-invasive assessment of myocardial injury; however, in vivo cDWI remains a major technical challenge since bulk and pulsatile motion of the beating heart make resolving molecular diffusion much more problematic than it is in the brain. A promising application for cDWI is in heart transplantation for surveillance of allograft rejection. Heart transplant (HT) patients undergo routine monthly endomyocardial biopsies (EMB) in the first year and annual intra-arterial coronary angiography (ICA) to monitor for acute and chronic rejection, respectively. These tests are invasive and carry risks of valve damage, renal failure and cardiac perforation. Additionally, this surveillance practice is resource-demanding, adding to the enormous cost of HT. For over 25,000 Americans living with HT, a non-invasive method of graft surveillance - allowing for safe deferral of costly and invasive tests - is highly desirable. The goal of this project is to develop a robust cDWI technique for clinical use, with initial validation in HT patients for non-invasive surveillance of acute and chronic rejection. We propose to overcome the current limitations of cDWI using a short-axis propeller echo-planar imaging (SAP- EPI) MR sequence. By combining the ultra-fast EPI technique with a novel SAP motion-correction algorithm, the challenge of physiologic motion will be addressed while minimizing image distortion of standard EPI; additionally, this acquisition method is inherently flexible and can be reconstructed for high-resolution and time- resolved cardiac imaging. Aim 1 is sub-divided into technical (1A) and clinical (1B) goals: Aim 1A is focused on cDWI sequence development and retrospective correction of motion- induced cardiac errors and signal loss. SAP motion- correction will be developed to deal with the physiologic motion of the beating heart. Aim 1B will explore if cDWI can detect acute myocardial damage in the setting of acute cellular rejection (ACR) in HT patients. cDWI data in HT patients with and without ACR determined by gold standard EMB will be compared. Aim 2 is also sub-divided into technical (2A) and clinical (2B) goals: Aim 2A is focused on an advanced technical development of our cDWI sequence from Aim 1, modified for intravoxel incoherent motion (IVIM) with the goal of developing semi-quantitative perfusion imaging which can be performed without a contrast agent. Aim 2B will explore if cDWI IVIM perfusion imaging detects altered blood flow in HT patients with cardiac allograft vasculopathy (CAV). Perfusion fractions will be measured in patients with and without evidence of CAV determined by the gold standard ICA. The end-point of the clinical aims is to validate cDWI in the HT population and achieve a general proof of concept that myocardial characterization with cDWI is an achievable and accurate clinical tool. Our results may provide a threshold of altered diffusion/perfusion with cDWI and IVIM that will predict a positive EMB/ICA result - with safe deferral of costly and invasive tests in HT patients below this threshold. In Summary, this proposal aims at creating a new, clinically feasible cDWI sequence which addresses the unresolved issues of physiologic cardiac motion, which has until now prevented development and clinical use of cDWI for cardiac tissue characterization. Developing a robust cDWI sequence may change the existing management paradigm of HT patients by providing a completely non-invasive and risk-free method of allograft surveillance. Ultimately, we expect that the availability of routine cDWI will unlock the potentially game-changing role which cDWI may also have for non-invasive assessment, of myocardial injury abnormal myocardial perfusion in the future.

项目摘要/摘要 弥散加权成像(DWI)具有既定的作用 在检测急性脑损伤方面，最显著的是在早期 检测中风。心脏弥散技术的应用- 加权磁共振成像(CDWI)对于非侵入性也有类似的意义 心肌损伤的评估；然而，在活体cDWI 仍然是一个重大的技术挑战，因为批量和 跳动的心脏的搏动使解决 分子扩散的问题比现在更严重 大脑。CDWI的一个很有前途的应用在心里 移植用于监测同种异体移植排斥反应。 心脏移植(HT)患者每月例行一次 第一年心内膜心肌活检(EMB)和 每年的动脉内冠状动脉造影术(ICA) 分别监测急性和慢性排斥反应。 这些测试是侵入性的，并带有瓣膜损坏的风险， 肾功能衰竭和心脏穿孔。此外，这一点 监控实践对资源要求很高，增加了 超音速飞行的巨大成本。为超过25,000名美国人 一种非侵入性的移植物移植方法--移植物移植 监控-允许安全地推迟成本高昂和 侵入性测试-是非常可取的。 这个项目的目标是开发一个健壮的cDWI 临床使用的技术，在HT中进行初步验证 患者对急性和非侵入性疾病的监测 慢性排斥。 我们建议克服cDWI目前的局限性。 使用短轴螺旋桨回波平面成像(SAP- EPI)MR序列。通过结合超高速EPI 技术和一种新的SAP运动校正算法， 生理学运动的挑战将被解决 同时最小化标准EPI的图像失真； 此外，这种获取方法具有固有的灵活性 并且可以以高分辨率和时间重建- 分解的心脏成像。 目标1细分为技术(1A)和临床(1B) 目标：目标1A专注于cDWI序列 运动的发展和追溯校正- 诱发心脏错误和信号丧失。SAP动议- 矫正将被开发来处理生理上的 跳动的心脏的运动。Aim 1B将探索cDWI 可以在以下设置中检测急性心肌损伤 高血压患者的急性细胞排斥反应(ACR)。CDWI数据 用GOLD检测伴和不伴ACR的HT患者 将对标准的EMB进行比较。 AIM 2还细分为技术(2A)和临床 (2B)目标：目标2A专注于高级技术 我们从Aim 1开发的cDWI序列，经过修改 用于体素内非相干运动(IVIM)，目标是 开发半定量灌注成像，可以 在没有造影剂的情况下进行。目标2B将 探索cDWI IVIM灌注成像是否检测到改变 同种异体心脏移植患者的血流变化 血管病(CAV)。血流灌注分数将是 在有和没有CAV证据的患者中进行测量 由金本位的ICA决定。 临床目的的终点是验证cDWI。 并得到了一个普遍的证明 CDWI心肌定征的概念是 一种可实现的、准确的临床工具。我们的结果 可提供扩散/灌流改变的阈值 预测EMB/ICA结果为阳性的cDWI和IVIM -安全地推迟昂贵和侵入性的HT测试 低于这一门槛的患者。 综上所述，这项建议旨在创造一个新的， 临床可行的cDWI序列，解决了 生理性心脏运动的悬而未决的问题 到目前为止已经阻止了这种药物的开发和临床应用 CDWI用于心脏组织定征。开发一个 稳健的cDWI序列可能会改变现有的 甲状旁腺功能衰竭患者的管理模式 完全无创、无风险的同种异体移植方法 监视系统。归根结底，我们预计 例行的cDWI将解锁潜在的改变游戏规则的 CDWI也可能在非侵入性疾病中发挥作用 心肌损伤的评估，异常心肌 未来的灌注期。