High Light Output Scintillator Camera for SPECT

描述（由申请人提供）：拟议项目的目标是建立和表征基于碘化锶的闪烁体成像阵列。这个最近发现的闪烁体提供了比任何其他用于SPECT的闪烁体高得多的光输出，同时也提供了与SPECT相关的光子能量的高停止功率。SPECT的最新发展，包括准直方案的创新以及专用心脏和临床前成像系统的构建，已经引起了人们对成像探测器的兴趣，这些探测器比传统的Anger Camera具有更好的性能，后者由大面积碘化钠晶体耦合到离散光电倍增管阵列组成。由于碘化锶的光输出要高得多，碘化锶成像探测器有望在能量分辨率上比Anger相机有显著的提高。我们预计140 keV的能量分辨率将超过5%，这大约是典型愤怒相机的两倍。能量分辨率的提高将允许应用更窄的能量窗口，减少图像中包含的散射光子的数量，从而提供改进的图像对比度和更好的定量精度。此外，能量分辨率的提高将转化为更好的双同位素SPECT能力。因为光输出也是空间分辨率的重要因素，所以碘化锶也提供了比碘化钠更好的空间分辨率的潜力。我们的策略是构建一个由单片碘化锶晶体组成的成像探测器，最大限度地减少对晶体封装的要求。该晶体将使用当前最先进的硅光电倍增管阵列读出，该阵列在碘化锶的发射光谱上提供高光子探测效率。我们将测量对成像性能重要的特性，包括空间分辨率、能量分辨率、检测效率、计数率能力和均匀性。

DESCRIPTION (provided by applicant): The objective of the proposed project is to build and characterize a scintillator imaging array based on strontium iodide. This recently discovered scintillator offers much higher light output than any other scintillator that has been used for SPECT, while also offering high stopping power at photon energies relevant for SPECT. Recent developments in SPECT, including innovation in collimation schemes and construction of dedicated cardiac and preclinical imaging systems, have created interest in imaging detectors offering better performance than the conventional Anger Camera, which consists of a large-area sodium iodide crystal coupled to an array of discrete photomultiplier tubes. A strontium iodide imaging detector is expected to offer a significant improvement in energy resolution over the Anger Camera due to the much higher light output of strontium iodide. We anticipate an energy resolution of better than 5% at 140 keV, which is approximately a factor of two better than the typical Anger Camera. Improvements in energy resolution would allow for narrower energy windows to be applied, reducing the number of scattered photons included in the image and thereby providing improved image contrast and better quantitative accuracy. Further, improvements in energy resolution would translate into better dual-isotope SPECT capability. Because light output is an important contributor to spatial resolution as well, strontium iodide also offers the potential for better spatial resolution than sodium iodide. Our strategy is to construct an imaging detector consisting of a monolithic strontium iodide crystal, minimizing the demands on crystal packaging. The crystal will be read out using current state-of-the-art silicon photomultiplier arrays, which offer high photon detection efficiency over strontium iodide's emission spectrum. We will measure properties important to imaging performance, including spatial resolution, energy resolution, detection efficiency, count-rate capability, and uniformity.