IMPROVED QUANTITATIVE ACCURACY OF SPECT-PET IMAGING

描述（改编自申请人的摘要）： 开发符合检测系统，可以添加到 现有的SPECT相机，以及药房网络，以提供FDG， 没有回旋加速器的医院， 因为使用放射性核素进行的成像研究数量大幅增加， 正电子发射器，例如FDG。 这项研究计划的目标是 研究提高定量准确性的技术， 使用这些新的符合检测系统的FDG肿瘤成像。 一 当前伽马照相机符合成像系统的主要限制是 有限的探测器计数率。 这项研究计划的一个重要目标是， 调查一些不同的数据收集策略， 提高了符合率。 申请人建议评估和 优化这些不同的战略，使用最近开发的统一 估计方差的Cramer-Rao（CR）界，它提供了对 可实现的特定估计任务的最佳性能 使用所测量的投影数据。 模拟各种数据采集 战略，他们提出修改蒙特卡罗模拟包 （SIMIND），其目前对SPECT成像进行建模，以允许跟踪 湮灭光子和它们的检测在符合使用两个或三个 头部旋转伽马相机 除了调查不同的数据 他们提出了重合检测系统的收集策略， 评估不同计算复杂度的重建方法，以及 衰减补偿、探测器响应和 散射会影响图像质量。 两个品质因数将用于 客观评估临床相关估计任务的性能， 模拟和临床数据。 为了计算这些基于任务的 品质因数，并评估其准确度和精密度，方法， 分析计算人口统计量，如平均值， 协方差矩阵和概率密度函数的图像获得 利用非迭代和加速迭代重建方法 将被开发。

DESCRIPTION (Adapted from Applicant's Abstract): The recent commercial development of coincidence detection systems that can be added on to existing SPECT cameras, as well as a pharmacy network to supply FDG to hospitals which do not have a cyclotron on-site, has provided the potential for a vast increase in the number of imaging studies performed using positron emitters such as FDG. The goal of this research proposal is to investigate techniques for improving the quantitative accuracy of FDG-oncological imaging using these new coincidence detection systems. A major limitation of current gamma camera coincidence imaging system is a limited detector count-rate. An important goal of this research plan will be to investigate a number of different data collection strategies for improving the coincidence rate. The applicants proposed to evaluate and optimize these different strategies using the recently developed uniform Cramer-Rao (CR) bound on estimator variance which provides a measure of the best possible performance for a specific estimation task that is achievable using the measured projection data. To simulate various data collection strategies, they proposed to modify a Monte Carlo simulation packaged (SIMIND) which currently models SPECT imaging, to allow for the tracking of annihilation photons and their detection in coincidence using a two or three headed rotating gamma camera. In addition to investigating different data collection strategies for coincidence detection systems, they proposed to evaluate reconstruction approaches of varying computational complexity, and the extent to which compensations for attenuation, detector response and scatter can affect image quality. Two figures of merit will be used to objectively assess performance of clinically relevant estimation tasks using both simulated and clinical data. To compute these task-based figures-of-merit and to evaluate their accuracy and precision, methods to analytically compute population statistical quantities, such as the mean, covariance matrix, and the probability density function of images obtained with both non-iterative and accelerated iterative reconstruction approaches will be developed.