High-Resolution Whole Heart Quantitative CMR Perfusion Imaging in Ischemic Heart Disease

7.项目总结 超过800万美国人因梗阻性冠状动脉疾病(CAD)或 微血管疾病(MVD)，两者都与心血管不良风险增加相关 事件，对梗阻性CAD的存在和功能意义的准确无创评估和 微血管密度的评估具有重要的临床意义。而CAD和MVD的特征都是 冠状动脉血流储备异常(CFR)，仅此参数不足以区分这两者 有不同管理策略的条件。高分辨率全心定量腺苷 应激心脏磁共振(CMR)有可能提供一种新的工具来区分 这些实体基于其量化心内膜和心外膜血流灌注差异的能力。 然而，3D定量腺苷应激CMR仍然存在一些重要的局限性，包括 有限的空间覆盖、较低的面内空间分辨率、较长的时间采集窗口以及对 心脏和呼吸运动。我们一直在开发高效的高分辨率2D螺旋CMR灌注 脉冲序列，以克服这些限制，同时提供全心脏覆盖。 该项目的长期目标是开发健壮的高分辨率定量cmr血流灌注。 用全心覆盖技术了解动物血流灌注异常的发展 微血管疾病和梗阻性CAD的模型，并利用这些CMR技术来改进 冠心病和微血管病变患者的无创性诊断和危险分层。改进的诊断技术 用于评估冠心病和MVD的心肌血流灌注可显著减少对有创冠状动脉的需求 正在接受心绞痛评估的患者的血管造影术。 本项目的具体目标是：(1)开发一种高效的高分辨率二维螺旋血流灌注系统 健壮、运动不敏感和准确的心肌灌注和心内膜测量技术 心外膜(Endo：EP)灌注率。(2)检验CMR准确测量Endo的假设：EPI 在猪模型中，与MVD相比，梗阻性CAD的血流灌注率并检测到较低的Endo/EPI比率。 (3)开发一种使用CMR获得的MPR和Endo：EPI灌注率来区分CAD和 心绞痛和已知或疑似冠心病患者的微血管密度。 该项目的成功完成将带来一种高效、可靠且经过充分验证的技术，用于 分辨率全心定量心肌灌注能准确检测Endo：EPI灌注 定量MPR和心肌缺血负荷，并鉴别梗阻性CAD和MVD。这个 非常短的时间足迹和运动不敏感的重建将使强大的血流灌注量化在 心率加快和无法屏气的患者延长了CMR的适用范围。

7. Project Summary As greater than 8 million Americans suffer from angina due to obstructive coronary artery disease (CAD) or microvascular disease (MVD), which are both associated with an increased risk for adverse cardiovascular events, accurate non-invasive assessment of the presence and functional significance of obstructive CAD and evaluation of MVD is of substantial clinical importance. While both CAD and MVD are characterized by abnormal coronary flow reserve (CFR), this parameter alone is insufficient to distinguish between these two conditions which have different management strategies. High-resolution whole-heart quantitative adenosine stress cardiac magnetic resonance (CMR) has the potential to provide a new tool to differentiate between these entities based on its ability to quantify differences between endocardial and epicardial perfusion. However, 3D quantitative adenosine stress CMR still suffers from a number of important limitations including limited spatial coverage, low in-plane spatial resolution, long temporal acquisition windows, and sensitivity to cardiac and respiratory motion. We have been developing efficient high-resolution 2D spiral CMR perfusion pulse sequences to overcome these limitations while providing whole-heart coverage. The broad long-term objective of this project is to develop robust high-resolution quantitative CMR perfusion techniques with whole-heart coverage to understand the development of perfusion abnormalities in animal models of microvascular disease and obstructive CAD, and to utilize these CMR techniques to improve the non-invasive diagnosis and risk stratification of patients with CAD and MVD. Improved diagnostic techniques for assessing myocardial perfusion in CAD and MVD could significantly reduce the need for invasive coronary angiography among patients being evaluated for angina. The specific aims for this project are: (1) To develop an efficient high-resolution 2D spiral-based perfusion technique for robust, motion-insensitive and accurate measurements of myocardial perfusion and endocardial to epicardial (endo:ep) perfusion ratio. (2) To test the hypothesis that CMR accurately measures endo:epi perfusion ratios and detects a lower endo:epi ratio in obstructive CAD as compared to MVD in a porcine model. (3) To develop an algorithm using CMR derived MPR and endo:epi perfusion ratios to differentiate CAD from MVD in patients presenting with angina and known or suspected CAD. Successful completion of this project will result in an efficient, robust, and well-validated technique for high- resolution whole-heart quantification of myocardial perfusion able to accurately detect endo:epi perfusion gradients, quantify MPR and myocardial ischemic burden, and differentiate obstructive CAD from MVD. The very short temporal footprint and motion-insensitive reconstruction will enable robust perfusion quantification in patients with increased heart rates and inability to perform breath-holding extending the applicability of CMR.