Development of a combined Gamma/Positron system for molecular imaging of the human brain at sub-500 micron spatial resolution

开发伽玛/正电子组合系统，用于以亚 500 微米空间分辨率对人脑进行分子成像

• 批准号: 10722205
• 负责人: Shiva Abbaszadeh
• 金额: $ 43.22万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-18 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10722205
• 关键词: 3-Dimensional; Algorithms; Architecture; Brain; Brain imaging; Calibration; CdZnTe; Characteristics; Classification; Code; Compensation; Compton radiation; Computer software; Data; Deposition; Detection; Development; Discipline of Nuclear Medicine; Electronics; Elements; Event; Gamma Cameras; Gamma Rays; Geometry; Head; Housing; Human; Hybrids; Image; Imaging Phantoms; Isotopes; Joint repair; Laboratories; Language; Liquid substance; Maps; Measurement; Measures; Methods; Modeling; Motion; Noise; Outcome; Patients; Pattern; Performance; Phase; Photons; Physics; Positioning Attribute; Positron; Positron-Emission Tomography; Probability; Process; Radioisotopes; Recovery; Research Design; Resolution; Rodent; Rodent Model; Semiconductors; Signal Transduction; Sorting; Speed; Structure; System; Techniques; Technology; Time; Visualization; Work; Xenon; absorption; attenuation; classification algorithm; computerized data processing; deep learning; design; detection platform; detector; digital; human imaging; image reconstruction; imager; imaging modality; in vivo imaging; instrument; interest; kinematics; learning strategy; models and simulation; molecular imaging; novel strategies; phantom model; prototype; quantum; quantum sensing; radiotracer; reconstruction; simulation; theories; tomography; translation to humans; uptake; vector

SUMMARY We are proposing a new approach to a hybrid imaging modality that has been called “b+g” or “pamma-positron” Imaging [Gri07] that promises to simultaneously overcome 1) the sensitivity limits of single-gamma-ray-photon emission imaging, 2) the challenge of distinguishing between two different positron-emitting isotopes, and 3) the physics-based spatial resolution limits inherent in radioisotope imaging based on detection of positron- annihilation photons alone [Lan14]. The intent is to significantly advance molecular imaging of the human brain by allowing visualization of smaller substructures, quantification of smaller amounts of radiotracer uptake, and simultaneous measurement of multiple dynamic and spatial uptake patterns in advanced multi-isotope studies of normal brain function. The required elements to make this feasible comprise i) a detector approach for annihilation and gamma-ray photons that can yield rich data for precise energy, position, and timing estimation for both photoelectric and Compton interactions, ii) processing algorithms in firmware and software to sort and make optimal use of the various combinations of signals that can occur with and without coincidence, iii) reconstruction algorithms based on likelihoods that incorporate probabilities of emission, detection, positron range, non-collinearity, and Compton kinematics, and iv) detection and compensation for attenuation and subject motion – effects that if not addressed will become limiting factors for resolution and image quality. In contrast to early efforts to accomplish b+g imaging with liquid xenon detectors [Gri07], scattering detectors as inserts into PET scanners [Yos20], or planar semiconductor detectors paired with scintillation cameras [Lan14], we propose instead to develop and demonstrate a single detector technology and associated data processing methods that can be used for both 511 keV annihilation photons and the higher-energy, singly- emitted gamma rays. Abbaszadeh (MPI) and Levin have pioneered an edge-on crossed-strip cadmium zinc telluride (CZT) detector approach to PET detectors that provides an ideal starting point [Abb16]. Among their attributes are high stopping power based on the edge-on geometry, 3D positioning that minimizes parallax, excellent energy resolution, and dynamic range up to 1.2 MeV in maximum photon energy deposited per interaction. Furthermore, when a photon undergoes an initial scatter followed by a photoelectric absorption, these modules yield data vectors that allow position and energy estimation for both interactions that can be analyzed with Compton kinematics [Abb17]. We will carry out a 2-year simulation and proof-of-principle phase (UG3) in which we demonstrate b+g detection with edge-on CZT modules and measure detector characteristics, develop simulations that support reconstructions, and demonstrate acquisitions with single and multiple isotopes. We will carry out a three-year UH3 phase to build a tomographic system with a field of view sufficient to investigate imaging of sophisticated dynamic phantoms and in vivo imaging of rodent brain, as a design study and precursor to a human brain system.

概括 我们正在提出一种新的方法，用于混合成像方式，该方法称为“ B+G”或“ Pamma-positron” 成像[GRI07]有望同时克服的成像1）单γ射线 - 光子的灵敏度极限 排放成像，2）区分两个不同正电子的同位素的挑战，3） 基于物理学的空间分辨率限制了放射性同位素成像中固有的，基于正电子的检测 仅歼灭照片[LAN14]。目的是显着推进人脑的分子成像 通过允许可视化较小的子结构，较小量的放射性示意剂摄取和 简单测量高级多相关研究中多种动态和空间吸收模式 正常的大脑功能。使此可行完整的所需元素i）一种检测器方法 可以产生丰富数据的精确能量，位置和时机估计的歼灭和伽马射线照片 对于光电和康普顿交互，ii）固件和软件中的处理算法进行排序和 最佳使用有或不偶然发生的各种信号组合，iii） 重建算法基于结合发射，检测，正电子可能性的可能性 范围，非共线性和康普顿运动学以及iv）检测和补偿衰减和受试者 运动 - 如果未解决的话，将成为解决方案和图像质量的限制因素。 与早期使用液体氙气检测器[GRI07]完成B+G成像的努力相反，散射 探测器作为插入PET扫描仪[YOS20]或平面半导体检测器与闪烁配对 相机[LAN14]，我们建议开发和演示单个探测器技术和相关 可用于511 KEV歼灭照片和更高能源的数据处理方法 发出的伽玛射线。 Abbaszadeh（MPI）和Levin开创了一个边缘交叉的镉锌 telluride（CZT）检测器方法对宠物探测器提供了理想的起点[ABB16]。他们中间 属性是基于边缘的几何形状，3D定位的高停止功率，可最大程度地减少平行线的位置， 优秀的能量分辨率，动态范围高达1.2 MEV，以最大的光子能量沉积为 相互作用。此外，当光子经历初始散射随后是光电滥用时，这些 模块产生数据向量，允许可以分析这两种相互作用的位置和能量估计 与康普顿运动学[ABB17]。 我们将进行为期2年的模拟和原理证明（UG3），其中我们证明了B+G 使用边缘的CZT模块检测和测量探测器特征，支持的开发模拟 重建，并通过单个和多个同位素演示采集。我们将进行三年 UH3阶段以建立一个具有视野的层析成像系统，足以研究复杂的成像 动态幻象和啮齿动物大脑的体内成像，作为人脑系统的设计研究和前体。