MYOCARDIAL IMAGING IN ISCHEMIA AND INFARCTION

这一更新应用程序建立在两个新的放射性核素成像基础上 过去15个月一直由国家HBI赠款HL-21751资助的方法。 这些方法是在单次注射201T1后进行连续成像以区分 正常、存活的缺血和梗死心肌与 放射性标记心肌肌球蛋白特异性抗体识别急性心肌梗死 心肌梗死。我们现在收集了大量证据，证明 在系列成像研究中，201T1在初始缺陷中的重新分布是 主要与心肌存活有关。因此，在本议定书中 我们将探索客观评估序列成像序列的方法 以确定缺血状态、严重程度和可逆性。 ~(201)Tl心肌局部转运速率与肺组织浓度 ~(201)T_1与心肌的关系将被推导和测定。此外, 将制备放射性标记的抗肌球蛋白抗体并应用于临床。在……里面 除了标准的伽马相机成像，一个发射正电子的放射性标记，68 将使用GA进行冠状动脉内术后的横断面成像 放射性标记抗肌球蛋白的给药。已将新维度添加到 超声心动图对急性心肌缺血或梗死的评价 发射正电子的放射性核素18F-的定域化和核素的再分布 核磁共振波谱测定的内源~(19)F。 18F-是一种在急性心肌梗死后积聚的骨质疏松剂 并允许横向发射层析成像。我们将评估它的敏感性， 其特异度及其在量化脑梗塞面积中的应用。我们还有 发现存在一个容易确定的内源性心肌19F储存库 并且很容易用核磁共振检测到。初步研究表明，内源性 ~(19)F在缺血区耗尽。我们建议进一步评估 19F重新分发，并确定是否可能在 外周血液。通过阐明Tl的吸收和吸收的机制 清除，并将其与氟摄取和抗肌球蛋白沉积相关联， 脑缺血显像的敏感性、特异性及临床应用 心肌将得到增强。

This renewal application builds upon the two new radio-nuclide imaging approaches which have been funded for the past 15 months in NHBI Grant HL-21751. These approaches are serial imaging after a single dose of 201T1 to distinguish between normal, viable ischemic, and infarcted myocardium and gamma imaging of radiolabeled specific antibody to cardiac myosin to identify regions of acute myocardial infarction. We have now compiled substantial evidence that redistribution of 201T1 into initial defects on serial imaging studies is primarily related to myocardial viability. Accordingly, in the present protocol we will explore methods to objectively assess the serial imaging sequence in order to determine the ischemic state, its severity and its reversibility. Regional rate of myocardial 201T1 transport and the concentration of pulmonary 201T1 relative to myocardium will be derived and determined. In addition, radiolabeled antimyosin antibody will be prepared and applied clinically. In addition to a standard gamma camera imaging, a positron emitting radiolabel, 68 Ga will be employed to allow transverse section imaging after intracoronary administration of radiolabeled antimyosin. A new dimension has been added to the evaluation of acutely ischemic or infarcted myocardium by studying the localization of 18F-, a positron emitting radionuclide and the redistribution of endogenous 19F as determined by nuclear magnetic resonance (nmr) spectroscopy. 18F- is a bone seeking agent which accumulates in acutely infarcted myocardium and allows transverse emission tomography. We will evaluate its sensitivity, its specificity and its utility in quantification of infarct size. We have also found that an easily defineable reservoir of endogenous myocardial 19F exists and is easily detected with nmr. Preliminary studies suggest that endogenous 19F is depleted from ischemic myocardial zones. We propose to further evaluate 19F redistribution and determine if a 19F leak might be detected in the peripheral blood. By elucidating the mechanisms of thallium uptake and clearance, and correlating these with fluoride uptake and antimyosin deposition, the sensitivity, specificity and clinical application of imaging the ischemic myocardium will be enhanced.