Physical limits of quantitative ECT

描述（由申请人提供）：在本次更新申请中，我们继续研究定量SPECT成像的基本限制，并将范围扩大至包括PET。我们完成了我们在脑SPECT成像专用准直领域的努力，并在心脏SPECT成像和PET飞行时间（TOF）成像领域增加了新的重点。我们的目标仍然是双重的：开发定量的基于任务的系统评估指标，并使用这些指标来量化ECT成像系统的改进价值。在拟议的项目期间，我们将专注于成像系统的最基本方面，数据采集，这决定了最终的定量限。我们将评估三个最近的硬件进步的优点，在与阿尔茨海默病，帕金森病和心血管疾病相关的估计任务的性能。预期大脑和心脏硬件的改进均将在不影响空间分辨率的情况下提供大约一个数量级的灵敏度改进。类似地，将TOF信息添加到PET成像有望提供图像质量的实质性增益。在相对成熟的医学成像领域中，发现新的硬件修改来提供这种显著的改进是非常罕见的。在拟议的研究中，我们将量化估计任务性能的收益，预计定量脑和心脏成像从这三个进步，其中之一出现在以前的项目期间。我们将制造一个准直器，在前一个项目期间设计的，这是预计将增加灵敏度的大脑SPECT的，平均，一个因素10。我们还将评估高灵敏度专用心脏SPECT系统的性能，并量化PET TOF信息在大脑和心脏应用中的优势。将通过分析、模拟和实验确定活度浓度和动力学参数估计值的偏差和精度。将考虑一系列临床现实的噪声水平，包括噪声水平，我们以前已经证明，有效的估计非线性参数是不可能的。

DESCRIPTION (provided by applicant): In this renewal application, we continue our investigation of the fundamental limits on quantitative SPECT imaging and expand our scope to include PET. We complete our efforts in the area of special purpose collimation for brain SPECT imaging, and add new emphases in the areas of cardiac SPECT imaging and PET time-of-flight (TOF) imaging. Our goals remain two-fold: to develop quantitative task based metrics for system assessment, and to use these metrics to quantify the value of improvements to ECT imaging systems. In the proposed project period, we will focus on the most fundamental aspect of the imaging system, data acquisition, which determines the ultimate limits on quantitation. We will assess the merits of three recent hardware advances in terms of performance in estimation tasks related to Alzheimer disease, Parkinson disease, and cardiovascular disease. The brain and cardiac hardware improvements are each expected to provide about an order of magnitude improvement in sensitivity without compromising spatial resolution. Similarly, the addition of TOF information to PET imaging promises to provide substantial gains in image quality. It is extremely uncommon in relatively mature fields of medical imaging to discover new hardware modifications which promise to provide such a significant improvement. In the proposed research we will quantify the gains in estimation task performance to be expected for quantitative brain and cardiac imaging from these three advances, one of which emerged from the previous project period. We will manufacture a collimator, designed during the previous project period, which is expected to increase sensitivity of brain SPECT by, on average, a factor of 10. We will also assess the performance of a high-sensitivity dedicated cardiac SPECT system, and quantify the advantages of PET TOF information for both brain and cardiac applications. Bias and precision of estimates of activity concentration and kinetic parameters will be determined by analysis, simulation, and experiment. A range of clinically realistic noise levels will be considered, including noise levels at which we have previously shown that efficient estimation of nonlinear parameters is not possible.