End-to-End Optimization of SPECT Instrumentation, Acquisition, and Reconstruction

描述（由申请人提供）：单光子发射计算机断层扫描在许多重要心脏疾病的诊断和分期中发挥着重要且经过充分验证的作用，在美国和世界各地的许多临床研究中心广泛使用。最常见的应用是心肌灌注SPECT，以评估心血管疾病。一个新的和潜在的重要应用是I-123 MIBG SPECT（AdreView）心肌神经支配成像。虽然已经有大量的工作来开发改进的重建方法，以及一些工作来开发优化的仪器和采集参数，但这些工作在很大程度上是彼此孤立地完成的。问题如下：使用准直器响应补偿时，最佳准直器是什么？具有散射补偿的最佳能量窗口是什么？对于每个投影视图使用相同的采集时间是最佳的吗？每个患者使用相同的采集时间是否最佳？从未被提及此外，目前有许多用于心脏成像的专用扫描仪，其结合了几种新颖的功能以减少采集时间。其中一些是基于碲锌镉半导体探测器，提供改进的半峰全宽能量分辨率，但具有更复杂的能量响应，包括延伸到低能量的尾部。其他新的探测器材料，如具有改进的能量分辨率的LaBr，即将问世。然而，CZT和LaBr探测器的能量窗口和散射补偿方法尚未优化，它们对心脏成像的益处也没有经过严格的测试。在这项资助中，我们建议使用新的，最先进的基于任务的图像质量测量和经过临床研究校准的真实有效的模拟，对仪器，采集，重建和补偿参数和方法进行全面的端到端优化。我们将研究这些因素和采集时间/注射剂量之间的权衡，允许医生以降低辐射剂量来换取图像质量。结果将在提供改善的图像质量、诊断准确性和减少的患者剂量方面产生直接影响，同时还通过指导未来SPECT系统的开发而产生长期影响。这项工作还将提供使用投影域理想观察者的新型优化策略的验证，该观察者处理重建中使用的成像模型与真实成像过程之间的不匹配。

DESCRIPTION (provided by applicant): Single-Photon Emission Computed Tomography plays an important and well- validated role in the diagnosis and staging of a number of important cardiac diseases, and is widely used and available at many clinical sites in the US and around the world. The most common application has been myocardial perfusion SPECT to evaluate cardiovascular disease. A new and potentially important application is I-123 MIBG SPECT (AdreView) for myocardial innervation imaging. While there has been a great deal of work to develop improved reconstruction methods, and some work to develop optimized instrumentation and acquisition parameters, these have been done largely in isolation of each other. Questions such as: what is the optimal collimator when using collimator response compensation? what is the optimal energy window with scatter compensation?, is it optimal to use the same acquisition time for each projection view?, and is it optimal to use the same acquisition time per patient? have never been addressed. In addition, there are currently a number of dedicated scanners for cardiac imaging that incorporate several novel features to decrease acquisition time. Some of these are based on cadmium zinc telluride semiconductor detectors that provide improved full-width at half maximum energy resolution, but have a more complicated energy response that includes tails extending to low-energies. Other new detector materials such as LaBr with improved energy resolutions are on the horizon. However, energy windows and scatter compensation methods for CZT and LaBr detectors have not been optimized, nor has their benefit on cardiac imaging been rigorously tested. In this grant we propose to use novel, state-of-the art task-based image quality measures and realistic well-validated simulations calibrated by clinical studies to perform comprehensive end-to-end optimization of instrumentation, acquisition, reconstruction, and compensation parameters and methods. We will investigate the tradeoff between these factors and acquisition time/injected dose, allowing physicians to trade image quality for reduced radiation dose. The results would have an immediate impact in providing improved image quality, diagnostic accuracy, and reduced patient dose, while also having a longer term impact by guiding the development of future SPECT systems. The work will also provide validation of novel optimization strategies using projection-domain ideal-observers that handle mismatch between the imaging model used in the reconstruction and the true imaging process.