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。由CAD引起的心肌缺血的早期诊断很重要，因为冠状动脉血运重建和医疗疗法都可以显着降低发病率和死亡率。在没有阻塞性CAD的情况下，由于冠状动脉微循环异常，CMD是心肌缺血的主要原因。第一次通过心肌灌注心脏磁共振（CMR）是一种高度有前途的技术，用于检测缺血引起的区域血流缺陷。它不需要电离辐射，并且比核成像提供更高的空间分辨率。在与心肌缺血相关的静脉血管舒张应力描绘区域中获得的动态图像。尽管技术的改进和临床经验可观，但最近的多中心多生者研究（MR-IMPACT II）表明，尽管CMR检测CAD引起的缺血的敏感性优于SPECT（67％vs 59％），但特异性较低（61％vs 72％）。 CMR的灵敏度和特异性保持相对较低，表明实质性的假阳性和假阴性诊断。使用MBF CMR的几项研究表明，异常MBF可用于检测由CMD引起的缺血。但是，这些研究仅显示出适度的诊断准确性，表明需要进行重大改进。 MBF CMR的主要技术局限性导致CAD和CMD的诊断不准确的诊断包括：（i）图像伪影，例如深色边缘伪像（DRA）以及心脏和呼吸运动引起的人工制品，这降低了图像质量和诊断精度； （ii）LV不完整的覆盖范围，以评估总缺血负担； （iii）空间分辨率不足以可靠检测心脏心脏灌注缺陷； （iv） 由于血液增强时血液信号强度饱和而导致流量定量的AIF估计中的误差。在拟议的项目中，我们将开发新的技术来解决这些局限性（AIM 1）。这些技术将在动物中使用微球测量作为参考（AIM 2）进行严格验证。最后，将使用PET和侵入性冠状动脉反应性测试作为参考，在CAD和CMD患者中测试这些技术（AIM 3）。该项目的终点是具有全心覆盖范围，高各向同性分辨率，心脏相位分辨的采集，准确的动脉输入估计的新的心肌灌注定量CMR方法的开发和严格验证，而没有ECG触发或呼吸呼吸的要求。预计这种技术将显着提高图像质量，降低技术故障，提高诊断准确性，并促进最终采用心肌灌注CMR作为检测心肌缺血的选择方法。 。