METHODS FOR THE QUANTIFICATION OF MYOCARDIAL OXYGEN CONSUMPTION WITH 17O MRI

描述(由申请人提供)：在工业化国家，冠状动脉疾病(CAD)仍然是主要的死亡原因。在正常生理条件下，心肌血流量(MBF)、氧耗量(MVO2)与心肌机械功能密切相关。冠心病主要表现为心肌氧供需失衡。MVO2直接反映心肌氧供需平衡。准确评估心肌缺血状态，尤其是存活心肌，对于选择可能受益于冠状动脉血运重建术的患者至关重要。然而，在心肌中检测这种状态仍然是一个重要的临床问题，部分原因是在体内直接测量MVO2的固有困难，特别是在非侵入性和区域性的基础上。为了满足这种需求，我们的实验室正在开发一种新的技术，使用非侵入性磁共振成像(MRI)T1Rho技术和17O富集血示踪剂直接定量MVO2。然而，这项技术还没有得到优化，需要严格的验证。因此，我们的总体目标是优化和验证这项临床上可行的MRI技术，以可靠和一致地测量MVO2。该应用程序的目标将通过在幻影和犬类模型上进行一系列实验来实现。MRI测量MVO2的准确性将通过与金标准的比较来确定，例如用于血流测量的微球和用于测定心肌整体OEF的动脉和冠状静脉窦同步采血。将进行药物干预以改变狗的MVO2。这种对心肌代谢活动的直接评估可以显著提高MVO2测量的准确性和精密度。最终，所提出的方法可能有助于对CAD和其他心脏疾病进行全面的MRI评估。与公众健康相关：该项目旨在开发一种新的磁共振成像技术，用于直接量化心肌耗氧比。该技术将使用T1rho成像方法和注射17O标记的血液造影剂。直接测量耗氧比有助于对多种心脏疾病患者的综合评估。

DESCRIPTION (provided by applicant): Coronary artery disease (CAD) remains the leading cause of death in industrialized nations. Under normal physiological conditions, myocardial blood flow (MBF), oxygen consumption (MVO2), and myocardial mechanical function are intimately related. CAD manifests as imbalances between myocardial oxygen supply and demand. MVO2 directly reflects the balance of oxygen supply and demand of myocardium. Accurate assessment of myocardial ischemic status, particularly myocardial viability, is of paramount importance for selection of patients likely to benefit from coronary revascularization. However, detection of this status in myocardium remains an important clinical problem, partially owning to the inherent difficulty of direct measurement of MVO2 in vivo, particularly on a non-invasive and regional basis. In response to this need, our laboratory is developing a new technique to directly quantify MVO2 using non-invasive magnetic resonance imaging (MRI) T1rho techniques and 17O-enriched blood tracer. However, this technique has not been optimized and needs rigorous validation. Therefore, our overall objective is to optimize and validate this clinically viable MRI technique to measure MVO2 reliably and consistently. The goal of the application will be accomplished by pursuing a series of experiments in phantoms and a canine model. Accuracy of MVO2 measurement by MRI will be determined by comparing with gold standards such as microsphere for blood flow measurements and simultaneous blood sampling from artery and coronary sinus for the determination of myocardial global OEF. Pharmaceutical interventions will be performed to alter MVO2 in dogs. This direct assessment of metabolic activity in the myocardium may significantly improve the accuracy and precision of measurement of MVO2. Ultimately, the proposed methods may facilitate comprehensive MRI assessments of CAD and other cardiac diseases. PUBLIC HEALTH RELEVANCE: This project is to develop a new magnetic resonance imaging technique for direct quantification of myocardial oxygen consumption ratio. The technique will use T1rho imaging method and the injection of 17O-labeled blood contrast agent. Direct measurement of the oxygen consumption ratio may facilitate comprehensive evaluations of patients with a variety of cardiac diseases.