Lu-Free Scintillators for PET

用于 PET 的无 Lu 闪烁体

• 批准号: 9126643
• 负责人: KANAI SHAH
• 金额: $ 65.95万
• 依托单位: RADIATION MONITORING DEVICES, INC.
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-09 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9126643
• 关键词: Adsorption; Aluminum; Alzheimer' s Disease; Area; Biological; Biological Process; Body Image; Caliber; Carbon Isotopes; Ceramics; Cerium; China; Clinical; Country; Craniocerebral Trauma; Development; Diagnosis; Disease; Drops; Economics; Evaluation; Fluorine; Functional Imaging; Future; Gadolinium; Gallium; Goals; Growth; Health; Healthcare; Image; Imaging Techniques; Ions; Japanese Population; Label; Life; Light; Lutetium; Malignant Neoplasms; Marketing; Measures; Medical Imaging; Minerals; Mining; Nitrogen; Oils; Optics; Output; Oxides; Oxygen; Performance; Phase; Photons; Physics; Policies; Politics; Positron; Positron-Emission Tomography; Powder dose form; Preparation; Price; Procedures; Process; Production; Property; Radioactivity; Rare Earth Metals; Relative (related person); Reporting; Research; Resolution; Route; Sampling; Site; Source; Stroke; Symptoms; System; Technology; Tennessee; Testing; Thick; Time; Universities; analog; base; cost; density; design; detector; gadolinium oxide; improved; in vivo; interest; novel; operation; response; scale up

DESCRIPTION (provided by applicant): Positron Emission Tomography (PET) is a functional imaging technique with the potential to quantify the rates of biological processes in vivo. PET imaging can provide diagnosis for symptoms of diseases such as cancer, Alzheimer's disease, head trauma, and stroke. However, to allow exploitation of the full potential of PET, there is urgent need for both improvement in the performance of PET systems and reduction in their cost. Both of these factors are strongly influenced by the available detector technology. Scintillation crystals are currently used as detectors in PET. Requirements for the scintillation crystals used in PET include fast response, high sensitivity, high light output, high energy and timing resolution, and low cost. At present, most PET systems use crystals of Lu2SiO5:Ce (LSO) or its derivative LYSO, which satisfy most of the requirements listed above. Nevertheless, issues remain with the cost and availability of lutetium that must be considered with respect to the future production of scintillators for PET and when developing potential new scintillators. There are several diverse factors that influence the cost and availability of the lutetium oxide material used in LSO/LYSO crystal growth for PET, but perhaps the most fundamental is geological. The main mineral sources for lutetium are xenotime (LuPO4) and ion adsorption clays, both of which are predominately found in China. There is very little production of lutetium from any other country. It is difficult to make long term predictions of China's strategy with respect to rare earth exports, but recent years have seen ever increasing production controls and higher tariffs on exported rare earth materials in general. On the other hand, gadolinium, also an attractive rare earth element for scintillators, can be found in several different minerals including monazite, which exist in various parts of the world, thus making it's availability less dependent on the economy and politics of a single nation. Gadolinium offers some additional advantages compared to lutetium. Its natural abundance in the earth's crust is an order of magnitude greater than lutetium, and its larger ionic size makes it considerably easier to separate and purify relative to the smaller rare earth ions such as lutetium. These two fundamental factors combine to offer the potential of significantly lower cost for the same level of purity (by a factor of ~15). The larger ionic size also means that it provides a substitutional site for cerium that is better matched to the relatively large size of the cerium ion. Finally, unlke lutetium, gadolinium has no natural radioactivity, an additional benefit. In view of the serious concerns about availability and cost of Lu, the goal of the proposed project is to investigate novel Lu-free scintillators for PET imaging. The idea is to achieve reduction in cost, maintain a predictable supply of raw materials, and exceed the performance of LSO. In view of the advantages cited above, we plan to design the new scintillator based on Gd3+ as the rare earth ion and incorporating it into a cubic garnet matrix.

描述（由申请人提供）：正电子发射断层扫描（PET）是一种功能成像技术，具有量化体内生物过程速率的潜力。 PET成像可以为癌症，阿尔茨海默氏病，头部外伤和中风等疾病的症状提供诊断。但是，为允许剥削宠物的全部潜力，迫切需要提高宠物系统的性能和降低成本。这两个因素都受到可用探测器技术的强烈影响。闪烁晶体目前用作宠物的探测器。 PET中使用的闪烁晶体的要求包括快速响应，高灵敏度，高光输出，高能量和计时分辨率以及低成本。目前，大多数宠物系统都使用LU2SIO5：CE（LSO）的晶体或其衍生作用液体，它们满足了上面列出的大多数要求。尽管如此，在未来的宠物闪烁体生产以及开发潜在的新闪烁体时，必须考虑的卢特族的成本和可用性仍然存在问题。有几种不同的因素会影响PET LSO/LYSO晶体生长中使用的氧化lutetium材料的成本和可用性，但也许最基本的是地质。 Lutetium的主要矿物质来源是异种（LUPO4）和离子吸附粘土，两者主要在中国发现。任何其他国家的lutetium生产很少。对于稀土出口方面的中国战略，很难长期预测，但是近年来，总体而言，对出口稀土材料的产量控制和更高的关税越来越高。另一方面，在包括在世界各地存在的几种不同的矿物质中可以找到Gadolinium，这也是闪烁体的有吸引力的稀土元素，包括独居者，因此可用性降低了单个国家的经济和政治的依赖。与lutetium相比，Gadolinium提供了一些额外的优势。它在地壳中的天然丰度比Lutetium大的数量级，并且其更大的离子尺寸使相对于较小的稀土离子（如lutetium）进行分离和纯化的范围要容易得多。这两个基本因素结合起来，提供了相同纯度水平的显着较低成本的潜力（约为15倍）。较大的离子尺寸还意味着它为葡萄园提供了一个替代地点，该处用位置可以更好地匹配相对较大的瓷器离子。最后，lutke，Gadolinium没有自然的放射性，这是一个额外的好处。鉴于对LU的可用性和成本的严重关注，该项目的目标是调查新型的无LU闪烁体用于PET成像。这个想法是为了降低成本，维持可预测的原材料供应，并超过LSO的性能。鉴于上面引用的优势，我们计划将基于GD3+的新闪烁体设计为稀土离子，并将其纳入立方石榴石基质。