Synthetic-Collimator SPECT with Semiconductor Detectors

带有半导体探测器的合成准直器 SPECT

• 批准号: 8300089
• 负责人: Todd E Peterson
• 金额: $ 35.57万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8300089
• 关键词: Address; Algorithms; Animals; Area; Beds; Binding; Brain; Calibration; Clinical; Collimator; Corpus striatum structure; Data; Development; Devices; Discipline of Nuclear Medicine; Dopamine Antagonists; Dopamine D2 Receptor; Dopamine Receptor; Dose; Estimation Techniques; Event; Future; Gamma Cameras; Generations; Germanium; Haloperidol; Head; Image; Imaging Techniques; Ligands; Measurement; Measures; Methods; Mus; Nervous System Physiology; Neurologic Dysfunctions; Performance; Photons; Positioning Attribute; Procedures; Radiation; Research; Resolution; Semiconductors; Silicon; Structure; System; Techniques; Technology; Testing; Time; Tissues; analytical tool; base; computerized data processing; computerized tools; design; detector; drug development; image reconstruction; improved; in vivo; innovation; millimeter; molecular imaging; nervous system disorder; novel strategies; pre-clinical; prototype; radioligand; radiotracer; reconstruction; single photon emission computed tomography; tool

DESCRIPTION (provided by applicant): The objective of the proposed project is to improve preclinical molecular imaging capabilities using the synthetic-collimator imaging approach, which is an innovative SPECT technique in which tomographic images are reconstructed from multi-pinhole projection data collected at multiple magnifications. Preclinical imaging tasks, particularly molecular imaging of the mouse brain, demand both high spatial resolution and good sensitivity. Sub-millimeter spatial resolution is needed to resolve brain structures, while high sensitivity is needed to avoid pharmacologic effects associated with excessive ligand mass, limit radiation dose, and keep imaging times short. To address these competing demands, we will employ silicon and germanium detectors together. Each provides better spatial resolution than can be achieved with conventional scintillation cameras, making it possible to achieve a given spatial resolution at a lower pinhole magnification. Lower magnification, in turn, allows for a greater number of pinholes per unit detector area to be used. As this particular germanium detector technology has not previously been applied to preclinical SPECT, an initial task will be to optimize the signal processing and then characterize the detector performance as a gamma camera. Then a SPECT imaging system utilizing two camera heads, each with a silicon detector and a germanium detector stacked one behind the other, will be built. This design will allow for imaging to be done using photon emissions of two different energies at two different pinhole magnifications simultaneously. In addition to improving the sensitivity through the use of a unique two detector-layer approach, this method also enables tomographic reconstruction of multiplexed projection data, which further improves sensitivity by allowing a greater number of pinholes to be used. Specialized calibration procedures and iterative reconstruction algorithms will be implemented. Computational and analytical tools will be used to guide collimator design, image-acquisition strategy, and to compare experimental measurements to expected performance. Finally, the imaging capabilities of the multi- pinhole SPECT system will be demonstrated through the measurement of striatal binding in the mouse brain of a dopamine D2-receptor radioligand. These measurements will be compared to both to ex vivo measures and to analogous imaging measurements made with a commercial small-animal SPECT system. Overall, on a per detector-area basis this approach should provide a unique combination of spatial resolution and sensitivity for preclinical SPECT imaging studies.

描述（由申请人提供）：拟议项目的目的是使用合成 - 授权器成像方法提高临床前分子成像能力，这是一种创新的SPECT技术，其中从多个大型上收集的多块孔投影数据中重建了层析成像图像。临床前成像任务，尤其是小鼠大脑的分子成像，都需要高空间分辨率和良好的灵敏度。需要亚毫米的空间分辨率来解决大脑结构，而需要高灵敏度以避免与过度配体质量相关的药理作用，限制辐射剂量，并使成像时间短。为了满足这些竞争要求，我们将一起使用硅和锗探测器。每个传统闪烁摄像机都可以实现每个空间分辨率更好的空间分辨率，从而使以较低的针孔放大倍数获得给定的空间分辨率成为可能。反过来，较低的放大倍数允许使用更多单位检测器区域的针孔数量。由于以前尚未将这种特殊的锗检测器技术应用于临床前SPECT，因此最初的任务将是优化信号处理，然后将检测器性能描述为伽马摄像头。然后，将使用两个相机头的Spect Imaging系统，每个相机头都有一个硅探测器，将建造一个在另一个后面堆叠的锗探测器。该设计将允许使用两个不同的针孔：同时使用两个不同能量的光子发射进行成像。除了通过使用唯一的两个检测器层方法来提高灵敏度外，该方法还可以重建多路复用投影数据，从而通过允许使用更多的针孔来进一步提高灵敏度。将实施专门的校准程序和迭代重建算法。计算和分析工具将用于指导准直仪设计，图像收购策略，并将实验测量与预期性能进行比较。最后，将通过测量多巴胺D2受体放射性体的小鼠脑中的纹状体结合来证明多针孔系统的成像能力。这些测量值将被比较到离体测量和用商业小动物SPECT系统进行的类似成像测量。总体而言，在每个探测器区域基础上，这种方法应为临床前SPECT成像研究提供空间分辨率和敏感性的独特组合。