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一种基于碘化锶的闪烁体成像阵列。这种最近发现的闪烁体提供了比任何其他用于SPECT的闪烁体更高的光输出，同时在与SPECT相关的光子能量下也提供了高阻挡能力。SPECT的最新发展，包括准直方案的创新和专用心脏和临床前成像系统的构建，引起了人们对成像探测器的兴趣，成像探测器的性能优于传统的ANGE相机，后者由一个大面积的碘化钠晶体连接到一个离散的光电倍增管阵列组成。由于碘化锶的光输出要高得多，预计碘化锶成像探测器将大大提高能量分辨率，而不是ANGER相机。我们预计140keV的能量分辨率将优于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，从而减少图像中包含的散射光子的数量，从而提供更好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。由于光输出也是空间分辨率的重要贡献因素，碘化锶也提供了比碘化钠更好的空间分辨率的潜力。我们的战略是构建一个由单块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。晶体将使用目前最先进的硅光电倍增管阵列读出，这种阵列提供了比碘化锶发射光谱更高的光子探测效率。我们将测量对成像性能重要的属性，包括空间分辨率、能量分辨率、探测效率、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.