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）：拟议项目的目标是使用合成准直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，其中断层扫描图像是根据在多个放大倍率下收集的多针孔投影数据重建的。临床前成像任务，特别是小鼠大脑的分子成像，需要高空间分辨率和良好的灵敏度。需要亚毫米空间分辨率来解析大脑结构，同时需要高灵敏度来避免与过量配体质量相关的药理作用、限制辐射剂量并保持较短的成像时间。为了满足这些相互竞争的需求，我们将同时使用硅和锗探测器。每种技术都提供比传统闪烁相机更好的空间分辨率，从而可以在较低的针孔放大倍率下实现给定的空间分辨率。反过来，较低的放大倍数允许在每单位检测器面积上使用更多数量的针孔。由于这种特殊的锗探测器技术之前尚未应用于临床前 SPECT，因此最初的任务是优化信号处理，然后将探测器性能表征为伽马相机。然后，将建造一个采用两个摄像头的 SPECT 成像系统，每个摄像头都有一个堆叠在一起的硅探测器和锗探测器。该设计将允许同时使用两种不同能量的光子发射以两种不同的针孔放大倍数来完成成像。除了通过使用独特的两层检测器方法提高灵敏度之外，该方法还能够对多重投影数据进行断层扫描重建，从而通过允许使用更多数量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器设计、图像采集策略，并将实验测量结果与预期性能进行比较。最后，多针孔 SPECT 系统的成像能力将通过测量小鼠大脑中多巴胺 D2 受体放射性配体的纹状体结合来证明。这些测量结果将与体外测量结果以及商业小动物 SPECT 系统进行的类似成像测量结果进行比较。总体而言，在每个探测器区域的基础上，这种方法应该为临床前 SPECT 成像研究提供空间分辨率和灵敏度的独特组合。