New Dual-Mode Detector for Cerebrovascular Imaging

我们将开发一种新的双模脑血管成像仪器，结合计算机断层扫描（CT）和单光子发射计算机断层扫描（SPECT），以提高中风的诊断。CT和SPECT的同时测量将用于结构和功能的相关性，与单独SPECT相比，这将改善放射性核素摄取的量化。与单独的CT数据相比，通过获取与SPECT数据共配准的CT图像可以获得更详细的解剖信息。该成像系统将结合新型固体探测器、闪烁体和新型集成电路信号处理技术，为救护车或急诊室的快速卒中评估或重症监护病房的后续患者评估提供高质量的便携式仪器成像。在第一阶段，我们将开发具有一系列像素大小的新型硅光电二极管的小型阵列，用于每个CT和SPECT检测器。新的光电二极管将分别使用cdw0和Csl（TI）闪烁体进行CT和SPECT表征，并使用传统电子器件。由我们UCSF合作者开发的商用专用集成电路（ASIC）和双模ASIC将被评估与CT/SPECT系统一起使用。第二阶段项目将包括硅光电二极管的优化、用于信号处理的优化集成电路的设计和制造、原型阵列模块的制造和组装，以及在充满放射性同位素的幻影的成像应用中对原型模块进行测试。第一阶段可行性研究的结果将确定新的光电二极管设计是否需要修改以与CdWO4和Csl（TI）闪烁体一起使用，哪种ASIC最适合在此应用中使用，以及ASIC在第二阶段工作中需要哪些类型的修改/改进。拟议的商业应用：在III期，我们将基于I期和II期的努力将单个和多个检测器模块商业化，用于脑血管CT/SPECT成像仪器的临床应用。单个硅光电二极管设计将与不同的闪烁体一起用于x射线和放射性核素成像，以实现改进的性能特征，更快的诊断能力，并降低CT和SPECT的成本。硅光电二极管和信号处理电子学是基于低成本可靠的硅平面处理技术。此外，低成本的硅光电二极管可以取代在其他SPECT和PET应用中广泛使用的昂贵的PMT对偶体。

We will develop a new dual-modality cerebrovascular imaging instrument, combining both computed tomography (CT) and single photon emission computed tomography (SPECT), for improved diagnosis of stroke. Simultaneous measurement of CT and SPECT will be used for structural and functional correlation which results in improved quantification of radionuclide uptake in comparison to SPECT alone. More detailed anatomical information can be obtained by acquiring a CT image that is co-registered with the SPECT data, compared with CT data alone. The proposed imaging system will incorporate new solid state detectors, combined with scintillators, and new integrated circuit signal-processing technology, which will offer superior imaging quality in a portable instrument for rapid stroke assessment in the ambulance or emergency room setting, or for follow-up patient assessment in the critical care unit. In Phase I, we will develop small arrays of new silicon photodiodes, with a range of pixel sizes, for use in each of the CT and SPECT detectors. The new photodiodes will be characterized with CdW0O and Csl(TI) scintillators for CT and SPECT, respectively, with conventional electronics. A commercially available application specific integrated circuit (ASIC) and a dual-mode ASIC developed by our UCSF collaborators will be evaluated for use with the CT/SPECT system. The Phase II project will include optimization of the silicon photodiodes, design and fabrication of optimized integrated circuits for signal processing, fabrication and assembly of prototype array modules, and testing of the prototype modules in an imaging application with radioisotope-filled phantoms. The results of the Phase I feasibility studies will determine whether the new photodiode designs will require modification for use with the CdWO4 and Csl(TI) scintillators, which of the ASICs is optimal for use in this application, and what types of modifications/improvements are required in the ASIC for the Phase II work. PROPOSED COMMERCIAL APPLICATIONS: In Phase III we will commercialize single and multiple detector modules based upon the Phase I and Phase II efforts, for clinical use in cerebrovascular CT/SPECT imaging instruments. A single silicon photodiode design will be used with different scintillators for x-ray and radionuclide imaging to achieve improved performance characteristics, more rapid diagnostic capability and reduced cost for CT and SPECT. The silicon photodiodes and signal-processing electronics are based on low cost reliable silicon planar processing techniques. In addition, the low cost silicon photodiodes can replace their expensive PMT counterparts which are extensively used in other SPECT and PET applications.