Whole-Heart Myocardial Blood Flow Quantification Using MRI

使用 MRI 定量全心心肌血流量

• 批准号: 9226051
• 负责人: Debiao Li
• 金额: $ 86.24万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9226051
• 关键词: Address; Adoption; Agreement; Animals; Blood; Blood flow; Breathing; Canis familiaris; Cardiac; Cause of Death; Clinical; Contrast Media; Coronary; Coronary Arteriosclerosis; Coronary artery; Darkness; Detection; Development; Diagnosis; Diagnostic; Disease; Early Diagnosis; Early treatment; Electrocardiogram; Failure; Goals; Heart; Image; Inferior; Intravenous; Intravenous Bolus; Ionizing radiation; Ischemia; Label; Left ventricular structure; Magnetic Resonance; Magnetic Resonance Imaging; Measurement; Medical; Methodology; Methods; Microcirculation; Microspheres; Microvascular Dysfunction; Modeling; Morbidity - disease rate; Morphologic artifacts; Motion; Myocardial; Myocardial Infarction; Myocardial Ischemia; Myocardial perfusion; Patients; Perfusion; Phase; Pisum sativum; Positron-Emission Tomography; Reference Standards; Regional Blood Flow; Resolution; Sensitivity and Specificity; Severities; Signal Transduction; Specificity; Stress; Techniques; Testing; Validation; Vasodilator Agents; Visual; Woman; base; blood flow measurement; clinical practice; cost; data acquisition; diagnostic accuracy; experience; heart motion; imaging modality; improved; mortality; novel; nuclear imaging; outcome forecast; perfusion imaging; public health relevance; respiratory; single photon emission computed tomography; temporal measurement

DESCRIPTION (provided by applicant): The broad, long-term objective of the proposed project is to improve the prognosis of patients with myocardial ischemia caused by coronary artery disease (CAD) or coronary microvascular dysfunction (CMD). Early diagnosis of myocardial ischemia caused by CAD is important as both coronary revascularization and medical therapies can significantly reduce morbidity and mortality. CMD is a major cause for myocardial ischemia in the absence of obstructive CAD, particularly in women, due to abnormalities in coronary microcirculation. First- pass myocardial perfusion cardiac magnetic resonance (CMR) is a highly promising technique for detecting regional blood flow deficits caused by ischemia. It does not require ionizing radiation and provides higher spatial resolution than nuclear imaging. Dynamic images acquired during intravenous vasodilator stress delineate regions associated with myocardial ischemia. Despite considerable technical improvements and clinical experience, a recent multicenter multivendor study (MR-IMPACT II) shows that while the sensitivity of CMR to detect ischemia caused by CAD is superior to SPECT (67% vs 59%), specificity is inferior (61% vs 72%). Both sensitivity and specificity of CMR remain relatively low indicating substantial false positive and false negative diagnoses. Several studies using MBF CMR have shown that abnormal MBF can be used to detect ischemia caused by CMD. However, these studies have shown only moderate diagnostic accuracy, indicating the need for major improvements. Major technical limitations of MBF CMR that contribute to inaccurate diagnoses of CAD and CMD include: (i) image artifacts, such as dark rim artifact (DRA) and cardiac and respiratory motion-induced artifacts, which reduce the image quality and diagnostic accuracy; (ii) incomplete coverage of the LV for evaluating total ischemic burden; (iii) inadequate spatial resolution for reliable detection of subendocardial perfusion deficits; and (iv) errors in AIF estimation for flow quantification due to saturation of blood signal intensity at pea enhancement. In the proposed project, we will develop novel techniques to address these limitations (Aim 1). The techniques will be rigorously validated in animals using microsphere measurements as the reference (Aim 2). Finally, the techniques will be tested in CAD and CMD patients using PET and invasive coronary reactivity testing as reference, respectively (Aim 3). The end point of the project is the development and rigorous validation of a new myocardial perfusion quantification CMR method with whole-heart coverage, high isotropic resolution, cardiac phase-resolved acquisition, accurate arterial input estimation while without the requirements of ECG triggering or breath-hold. It is expected that such a technique will significantly improve image quality, reduce technical failures, increase the diagnostic accuracy, and facilitate the eventual adoption of myocardial perfusion CMR as the method of choice for detecting myocardial ischemia. .

描述(由申请人提供)：拟议项目的广泛、长期目标是改善由冠状动脉疾病(CAD)或冠状动脉微血管功能障碍(CMD)引起的心肌缺血患者的预后。早期诊断冠心病引起的心肌缺血非常重要，因为冠状动脉血运重建和药物治疗都可以显著降低发病率和死亡率。在没有梗阻性CAD的情况下，由于冠状动脉微循环的异常，CMD是心肌缺血的主要原因，特别是在女性。首过心肌灌注心脏磁共振(CMR)是一种非常有前途的检测缺血引起的局部血流缺陷的技术。它不需要电离辐射，并且提供比核成像更高的空间分辨率。在静脉血管扩张剂负荷期间获得的动态图像描绘了与心肌缺血相关的区域。尽管有相当大的技术改进和临床经验，最近的一项多中心多供应商研究(MR-Impact II)显示，尽管CMR对检测CAD引起的缺血的敏感性高于SPECT(67%比59%)，但特异性较差(61%比72%)。CMR的敏感性和特异性仍然相对较低，表明存在大量的假阳性和假阴性诊断。几项使用MBF CMR的研究表明，MBF异常可用于检测CMD引起的缺血。然而，这些研究只显示出中等的诊断准确性，表明需要进行重大改进。MBF CMR对CAD和CMD的不准确诊断的主要技术限制包括：(I)图像伪影，如暗边缘伪影(DRA)和心脏和呼吸运动诱发的伪影，降低了图像质量和诊断准确性；(Ii)用于评估总缺血负荷的LV覆盖不完整；(Iii)空间分辨率不足，无法可靠地检测心内膜下灌注不足；和(Iv) 由于豌豆增强时血液信号强度饱和，血流定量的AIF估计错误。在拟议的项目中，我们将开发新的技术来解决这些限制(目标1)。这些技术将在动物身上进行严格的验证，使用微球测量作为参考(目标2)。最后，这些技术将在CAD和CMD患者中分别以PET和有创冠状动脉反应性测试为参考进行测试(目标3)。该项目的终点是开发和严格验证一种新的心肌灌注定量CMR方法，该方法具有全心脏覆盖、高各向同性分辨率、心脏相分辨采集、准确的动脉输入估计，而不需要心电触发或屏气。预计这种技术将显著改善图像质量，减少技术故障，提高诊断准确性，并有助于最终采用心肌灌注CMR作为检测心肌缺血的首选方法。。