Simulaneous Dual Isotope SPECT w/Cross Talk Correction

描述(申请人提供)：SPECT的一个独特功能是能够使用两种标记有不同同位素的药物发射不同能量的光子来同时测量不同的生理过程。同时从两个同位素获取投影数据的优势在于，它允许同时测量两个潜在相关的过程(例如，静息和应激灌注或灌注和受体密度)。这可能会增加额外的诊断信息，此外，这两项研究还具有实际优势，例如增加了患者吞吐量，消除了登记问题，并导致了共同的患者运动。然而，由于患者和伽马相机中的散射以及常规伽马相机能量分辨率较低，双同位素采集会导致两组投影数据的串扰污染。在这项工作中，我们假设我们可以开发同时获取和重建双同位素图像的方法，该方法可以减少这种串扰的影响，使图像具有接近单独获取时的诊断图像质量。我们选择了两个具体的应用：双核素~(99)m/TI-201负荷/静息心肌SPECT和双核素~(99)m/I-123脑SPECT，重点是~(99)Tc/TI-201脑SPECT。为此，我们建议：(1)开发优化和评估同步双核素心肌显像的方法；(2)开发和实施改进的双核素SPECT同步串扰补偿方法；(3)开发优化的双核素心肌灌注SPECT采集方法；(4)使用模拟数据和数学观察者对这些方法进行评估；(5)使用体模实验和图像质量的定量指标来评估同步双核素心肌断层扫描；(6)对同时和单独采集双同位素静息/负荷心肌灌注SPECT进行临床评估。考虑到这一过程的执行频率以及患者舒适度和临床吞吐量的显著改善，我们相信这将对临床实践产生重大影响。我们还将开发同时进行~(99)Tc-~(99)m/I-123脑成像的技术，随着新的I-~(123)和~(99)m标记脑显像剂的开发和上市，这些技术可能会被证明是重要的。

DESCRIPTION (provided by applicant): One unique feature of SPECT is the ability to use two pharmaceuticals labeled with different isotopes emitting photons with different energies to make simultaneous measurements of different physiological processes. Simultaneous acquisition of projection data from two isotopes has the advantage that it allows measurement of two potentially related processes (e.g., rest and stress perfusion or perfusion and receptor density) at the same time. This may add 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 gamma camera and the poor energy resolution of conventional gamma cameras, dual isotope acquisition will result in cross talk contamination of the two sets of projection data. In this work we hypothesize that we can develop methods for simultaneously acquiring and reconstructing dual isotope images that can reduce the effects of this cross talk to the point where the images have diagnostic image quality close to that which they would have if acquired separately. We have chosen to focus on two specific applications: dual isotope Tc-99m/ TI-201 stress/rest myocardial perfusion SPECT and dual isotope Tc-99m/I-123 brain SPECT, with major emphasis on Tc-99m/TI-201 imaging. Toward this end we propose to: (1) Develop methods for optimizing and evaluating simultaneous TI-201/Tc-99m imaging (2) Develop and implement improved cross talk compensation methods for simultaneous dual isotope SPECT (3) Develop optimized acquisition methods for Tc-99m/TI-201 myocardial perfusion SPECT; (4) To evaluate these methods using simulated data and mathematical observers; (5) To evaluate simultaneous dual isotope Tc-99m/I-123 SPECT using phantom experiments and quantitative measures of image quality; and (6) To perform a clinical evaluation of simultaneous and separate acquisition of dual isotope rest/stress myocardial perfusion SPECT. Given the frequency with which this procedure is performed and the significant improvement in both patient comfort and clinical throughput, we believe this would have a substantial impact on clinical practice. We also will have developed techniques for simultaneous Tc-99m/I-123 brain imaging that may prove important as new I-123 and Tc-99m labeled brain agents are developed and marketed.