DYNAMIC CARDIAC SPECT IMAGING

单光子发射计算机断层扫描(SPECT)已经成为一种重要的 诊断心脏病的工具，主要是因为它有 在评估心肌缺血方面显示出重要的临床作用 以及最近在评估心肌存活能力方面的研究。在过去的几年里 几年来，(201)Tl一直是用于 心脏SPECT。最近，像Sestamibi和teboroxe这样的药物 用~(99m)Tc标记以取代~(201)Tl。这个 同位素(99m)Tc比(201)Tl更受欢迎，因为它的光子更好 能量和辐射吸收剂量特性。然而，这些特工已经 未完全更换(201)TL，部分原因是其生理 特点。特别是，替波罗定的洗入和洗出速度很快。 来自心脏，这需要快速的断层扫描采集 此前，这一方案并不可行。然而，随着多元化的推进， 探测器SPECT系统，我们已经证明了动态心脏SPECT 替波罗酮的成像是可能的。动态心脏的研究进展 SPECT有可能提供一种比 目前的静态SPECT技术使用(201)Tl。 这项提案的目标是为动态 能够获得完整投影的心脏SPECT成像 设置完全三维组织分布的每5-10秒一次 一种生物半衰期短的放射性药物及其开发 数学工具从动态获取的数据中提取三个- 左侧运动参数的空间分布 心肌组织的血容量分数和洗入(K21) 和洗出(K12)速率常数。该提案将开发应用程序 精确、精确地量化动力学参数的数学工具 并通过计算机模拟系统地对这些方法进行评估， 犬只实验和临床研究。在完成这项工作后 还将具体说明建议书的设备要求。 这一建议借鉴了PET中生理学建模的发展。在… 目前，与SPECT相比，正电子发射计算机断层扫描(PET)在利用动态图像方面有很大进步 成像以提取器官系统的运动参数。这就是我们的意图 开发能够使用现有技术的方法 多探测器SPECT系统；通过这样做，提供更好的健康 通过更好的检测心肌梗死来照顾普通公众 梗塞，更好地诊断缺血性心脏病，以及更好的 在不增加SPECT额外成本的情况下评估组织活性 程序。所开发的许多方法也将适用于其他 器官系统，如肾脏和大脑。

Single photon emission computed tomography (SPECT) has become an important tool in the diagnosis of heart disease, primarily because it has demonstrated an important clinical role in evaluating myocardial ischemia and more recently in evaluating myocardial viability. Over the last several years, (201)Tl has been the primary radiopharmaceutical used for cardiac SPECT. More recently, agents like sestamibi and teboroxime labelled with (99m)Tc have been developed to replace (201)Tl. The isotope(99m)Tc is more desirable than (201)Tl because of its better photon energy and radiation absorbed dose properties. However, these agents have not totally replaced (201)Tl due in part to their physiological characteristics. In particular, teboroxime has a fast wash-in and wash-out from the heart which requires rapid tomographic acquisitions which previously has not been feasible. However, with the advancement of multi- detector SPECT systems, we have demonstrated that dynamic cardiac SPECT imaging of teboroxime is possible. The development of dynamic cardiac SPECT has the potential to offer a more sensitive measure of ischemia than the present static SPECT techniques using (201)Tl. The goal of this proposal is to prescribe clinical protocols for dynamic SPECT imaging of the heart that are able to acquire complete projection sets every 5-10 seconds of a full three-dimensional tissue distribution of a short biological half-life radiopharmaceutical and to develop mathematical tools to extract from the dynamically acquired data a three- dimensional spatial distribution of kinetic parameters in the left ventricular myocardial tissue of blood volume fraction and wash-in (k21) and wash-out (k12) rate constants. The proposal will develop the applied mathematical tools to accurately and precisely quantify kinetic parameters and systematically evaluate these methods with computer simulations, canine experiments and clinical studies. At the completion of this proposal equipment requirements will also be specified. This proposal draws upon the physiological modeling development in PET. At present, PET is much further advanced than SPECT in utilizing dynamic imaging to extract kinetic parameters of organ systems. It is the intent of this proposal to develop methods that would be able to use existing multi-detector SPECT systems; and, in so doing, to provide improved health care to the general public through better detectability of myocardial infarcts, better diagnosis of ischemic heart disease, and better evaluation of tissue viability without adding additional cost to the SPECT procedure. Many of the methods developed will also be applicable to other organ systems such as the kidney and the brain.