Tl-Halide Scintillators for TOF-PET

用于 TOF-PET 的卤化铊闪烁体

• 批准号: 10674007
• 负责人: JAROSLAW GLODO
• 金额: $ 62.95万
• 依托单位: RADIATION MONITORING DEVICES, INC.
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10674007
• 关键词: Address; Alzheimer' s Disease; Biological; Biological Process; California; Carbon Isotopes; Collaborations; Compensation; Coupled; Craniocerebral Trauma; Detection; Development; Diagnosis; Disease; Exhibits; Exposure to; Face; Fluorine; Functional Imaging; Geometry; Goals; Image; Imaging Techniques; Ions; LSO crystal; Label; Length; Light; Malignant Neoplasms; Methods; Nitrogen; Noise; Oxygen; Patients; Performance; Phase; Photons; Positron; Positron-Emission Tomography; Production; Property; Radiation; Radiation exposure; Resolution; Scanning; Scheme; Semiconductors; Stroke; Structure; Symptoms; System; Technology; Testing; Thick; Time; Universities; analog; cold temperature; cost; density; detection sensitivity; detector; improved; in vivo; interest; luminescence; manufacture; manufacturing cost; melting; response; simulation; virtual

Project Summary The current detector technology in PET requires scintillation that has fast response, excellent timing resolution, high detection sensitivity, good energy resolution, and last but not least acceptable cost. At present, most PET systems use crystals of LSO (Lu2SiO5:Ce) or its analog LYSO, which satisfy many of the listed requirements. But LSO, after years of development, has reached its performance limit, especially for the scanners with a long axial field of view (AFOV) that are currently being developed. The goal of these scanners is to increase the geometrical coverage and significantly increase detection sensitivity (by a factor of 30-40), thereby reducing the scanning times (30-40 times faster) or the patient’s radiation exposure. However, long AFOV scanners face two main challenges: greater depth-of-interaction (DOI) effects, which increase blurring and noise; and an increase in the volume required for the constituent crystals, which make up some 50% of the cost of the entire scanner. The use of shorter crystals can counteract both the DOI effects and the increased crystal volume (hence cost), but with a major loss of detection efficiency, defeating the original purpose. Another approach for reducing DOI effects is a double-ended read-out but this increases both cost and system complexity. Therefore, to achieve viable and affordable long AFOV scanners, a new scintillation material is required that would provide higher stopping power than LSO, with similar or better timing properties, and at a lower cost. These requirements can be met by a scintillator based on TlCl. This host has a comparable density (7.0 g/cm3 vs. 7.4 g/cm3 for LSO) and a much higher effective Z of 77 (vs. 65 to LSO.) When double doped with Be and I, it exhibits a fast donor-acceptor type luminescence with decay time <10 ns along with ultra-fast Cherenkov component (vs. 40 ns of LSO.) While the material’s light yield is low, its timing properties are excellent with better than 300 ps resolution FWHM when paired with LYSO, without any significant optimization. The only property where the material is deficient is its energy resolution (>15% at 511 keV, due to its low light yield). The key metric for TlCl is also its very low cost, in terms of raw materials as well as production – estimated 50% lower than LSO. In this project, we plan to optimize the doping content of TlCl to maximize its scintillation properties and achieve energy resolution of about 10% at 511 keV and timing resolution of 200 ps. In Phase II we will increase the volumes of produced material, develop cost reduction schemes, and produce and evaluate PET detection modules with the same performance goals.

项目摘要 当前的宠物探测器技术需要闪烁，具有快速响应，良好的时机 分辨率，高检测灵敏度，良好的能量解决方案以及最后但并非最不可接受的成本。现在， 大多数宠物系统使用LSO的晶体（LU2SIO5：CE）或其模拟液体，它满足了许多列表 要求。但是，经过多年的发展，LSO已达到其性能限制，尤其是 目前正在开发的具有长轴向视野（AFOV）的扫描仪。这些扫描仪的目标 是增加几何覆盖范围并显着提高检测灵敏度（倍数30-40）， 从而减少扫描时间（快30-40倍）或患者的辐射暴露。 但是，长长的AFOV扫描仪面临两个主要挑战：更大的相互作用（DOI）效应，这是 增加模糊和噪音；成分晶体所需的体积增加，这使得 增加了整个扫描仪成本的50％。较短的晶体的使用可以抵消DOI效应 以及增加的水晶体积（因此成本），但由于检测效率的重大损失，击败了 原始目的。降低DOI效果的另一种方法是双层读出 成本和系统复杂性。因此，要实现可行且负担得起的长期AFOV扫描仪，这是一个新的 需要闪烁的材料，它将提供比LSO更高的停止功率，具有相似或更好的时机 属性，成本较低。 基于TLCL的闪烁体可以满足这些要求。该宿主的密度可比（7.0 g/cm3 vs. 77 v/cm3的77（vs. 65 to lso）的有效z（lso）。 我，它表现出快速的供体型发光，衰减时间<10 ns以及超快速的Cherenkov 组件（vs. 40 ns lso。）虽然材料的光能产量较低，但其正时特性非常好，并且更好 与300 PS分辨率FWHM与Lyso配对时，没有任何明显的优化。唯一的财产 材料不足的地方是其能量分辨率（由于其低光产量，在511 KEV时> 15％）。关键指标 就原材料和生产而言，TLCL也是其成本非常低的成本 - 估计比LSO低50％。 在这个项目中，我们计划优化TLCL的掺杂含量，以最大化其闪烁属性和 在511 keV时达到约10％的能量分辨率，并分辨率为200 ps。在第二阶段，我们将增加 生产材料的体积，开发成本降低方案以及生产和评估宠物检测 具有相同性能目标的模块。