Simultaneous Dual Isotope SPECT W/Cross-Talk Correction

描述（由申请人提供）：SPECT的一个独特特点是能够同时从两种或多种药物中获取投影数据，每种药物都标记有发射不同能量光子的放射性同位素，允许同时测量多种生理过程，如休息/应激灌注或灌注/神经注入。这可以提供额外的诊断信息，此外，在两项研究中，有实际的优势，如增加患者吞吐量，消除注册问题和导致患者共同运动。然而，由于分散在病人和？由于常规伽玛相机能量分辨率较差，双同位素采集会导致两组投影数据的串扰污染。这项工作的总体目标是开发、优化和评估同时获取和重建双同位素图像的方法，这些方法可以减少这种串扰的影响，使图像具有接近单独获取的诊断图像质量。在本应用中，我们重点介绍了两种具体应用：双同位素99mTc应激/201Tl休息心肌灌注SPECT和双同位素99mTc灌注/123I神经支配心肌SPECT。在之前的融资周期中，我们已经描述了串扰并开发了补偿方法。由于这些方法允许将患者分为两个以上的诊断类别，例如，具有正常，缺血或梗死的心肌，我们开发了评估3级图像的方法。我们还开发了仿真工具，包括逼真的幽灵种群和模拟逼真SPECT数据的快速方法，用于优化和评估同时采集和串扰补偿方法。利用这些仿真工具，我们对补偿方法进行了初步的优化和评估。在这些研究中，我们已经证明了补偿方法显著降低了由于串扰而导致的图像质量下降，并且图像质量接近单独采集的图像质量。在本应用中，我们建议对这些方法进行严格的优化和验证，以证明它们的临床潜力和疗效。为此，我们建议：(1)进一步发展3类方法，对同时采集方法进行严格优化；(2)进一步开发和优化串扰补偿和同步采集方法；(3)通过动物和人体研究严格验证补偿方法；(4)探索同时采集三种同位素的可行性。考虑到静息/应激心肌灌注SPECT的频率和心脏病的患病率，同时获取心肌SPECT的方案具有很高的临床影响潜力。然而，在实现这种临床潜力之前，严格的验证是必不可少的。提出的研究有可能提供关于同时获取方法的效用的明确证据，从而对患者护理产生重大影响。公共卫生相关性：该项目的目标是开发、优化和评估同时成像心脏两种特性的方法。在一个子项目中，我们将开发在休息时和病人受到压力时心脏血流成像的方法；另一方面，我们开发了对血流和导致心脏跳动的神经受损区域进行成像的方法。这些方法有可能提供更好、更便宜的心脏病诊断。

DESCRIPTION (provided by applicant): One unique feature of SPECT is the ability to acquire projection data simultaneously from two or more pharmaceuticals each labeled with a radioisotope emitting photons with different energies, allowing simultaneous measurement of multiple physiological processes such as rest/stress perfusion or perfusion/innervation. This may provide additional diagnostic information and, in addition, there are practical advantages such as increased patient throughput, elimination of problems with registration and results in common patient motion in the two studies. However, due to scatter in the patient and ? camera and the poor energy resolution of conventional gamma cameras, dual isotope acquisition will result in crosstalk contamination of the two sets of projection data. The overall goal of this work has been to develop, optimize and evaluate methods for simultaneously acquiring and reconstructing dual isotope images that can reduce the effects of this crosstalk to the point where the images have diagnostic image quality close to that which they would have if acquired separately. In this application, we focus on two specific applications: dual isotope 99mTc stress/201Tl rest myocardial perfusion SPECT and dual isotope 99mTc perfusion/123I innervation myocardial SPECT. In the previous funding cycles, we have characterized the crosstalk and developed compensation methods. Since these methods allow classifying patients into more than two diagnostic classes, e.g., having normal, ischemic or infracted myocardium, we have developed methods for assessing 3-class image. We have also developed simulation tools, including realistic populations of phantoms and fast methods for simulating realistic SPECT data, for use in optimizing and evaluating the simultaneous acquisition and crosstalk compensation methods. Using these simulation tools, we have performed preliminary optimizations and evaluations of the compensation methods. In these, we have demonstrated that the compensation methods significantly reduce the degradation in image quality due to crosstalk and image quality approaching that from separate acquisition. In this application, we propose to perform rigorous optimization and validation of these methods in order to demonstrate their clinical potential and efficacy. Toward this end, we propose to: (1) further develop 3-class methods for rigorous optimization of the simultaneous acquisition methods; (2) further develop and optimize the crosstalk compensation and simultaneous acquisition methods; (3) rigorously validate rigorously the compensation methods using animal and human studies; and (4) explore the feasibility of simultaneous acquisition from three isotopes. Given the frequency of rest/stress myocardial perfusion SPECT, and the prevalence of heart disease, simultaneous acquisition protocols for myocardial SPECT have a high potential for clinical impact. However, rigorous validation is essential before this clinical potential can be realized. The proposed studies have the potential to provide definitive evidence about the utility of simultaneous acquisition methods, and thus to have a significant impact on patient care. PUBLIC HEALTH RELEVANCE: The goal of this project is to develop, optimize, and evaluate methods for imaging two properties of the heart at the same time. In one subproject we will develop methods to image the blood flow in the heart at rest and when the patient has been stressed; in the other we develop methods to image blood flow and areas where the nerves causing the heart to beat are damaged. These methods have the potential to provide better and cheaper diagnosis of heart problems.