Simultaneous Dual Isotope SPECT W/Cross-Talk Correction

描述（由申请人提供）：SPECT的一个独特特征是能够同时从两种或更多种药物采集投影数据，每种药物都标记有放射性同位素，发射具有不同能量的光子，允许同时测量多个生理过程，例如静息/应激灌注或灌注/神经支配。这可以提供额外的诊断信息，此外，还具有实际优势，例如增加患者吞吐量，消除配准问题，并导致两项研究中的常见患者运动。然而，由于患者体内的散射和？由于双同位素相机的能量分辨率低和传统伽马相机的能量分辨率差，双同位素采集将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，优化和评估的方法，同时采集和重建双同位素图像，可以减少这种串扰的影响，图像的诊断图像质量接近，如果他们会单独收购的点。在这项应用中，我们专注于两个具体的应用：双同位素99 mTc负荷/201 Tl静息心肌灌注SPECT和双同位素99 mTc灌注/123 I神经支配心肌SPECT。在之前的融资周期中，我们已经对串扰进行了表征，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，对于正常、缺血或梗死心肌，我们开发了用于评估3级图像的方法。我们还开发了仿真工具，包括现实人口的幻影和快速的方法来模拟现实的SPECT数据，用于优化和评估的同时采集和串扰补偿方法。使用这些仿真工具，我们已经进行了初步的优化和评估的补偿方法。在这些中，我们已经证明，补偿方法显着减少由于串扰和图像质量接近，从单独的采集图像质量的退化。在本申请中，我们建议对这些方法进行严格的优化和验证，以证明其临床潜力和有效性。为此，我们建议：（1）进一步开发用于同时采集方法的严格优化的3类方法;（2）进一步开发和优化串扰补偿和同时采集方法;（3）使用动物和人体研究严格验证补偿方法;以及（4）探索从三种同位素同时采集的可行性。考虑到静息/负荷心肌灌注SPECT的频率和心脏病的患病率，心肌SPECT的同步采集协议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。拟议的研究有可能提供有关同时采集方法的实用性的明确证据，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、优化和评估同时对心脏的两种特性进行成像的方法。在一个子项目中，我们将开发方法来成像心脏中的血流在休息时，当病人一直强调;在另一个我们开发的方法来成像血流和导致心脏跳动的神经受损的区域。这些方法有可能为心脏问题提供更好、更便宜的诊断。

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.