New Multi-Channel ASIC and Si Detector for Gamma Cameras

描述（由申请人提供）： 我们将为新型固态伽马相机开发一种新型探测器模块，与当前可用的系统相比，它将提供卓越的上级性能，能够提供出色的能量分辨率、低至27 keV的良好灵敏度（用于小动物成像应用），并且能够清晰地分离用于双同位素成像应用的近距离较高能量伽马射线。这种新的伽马相机技术将基于Photon Imaging的新型硅光电二极管和布鲁克海文国家实验室（BNL）的科学家最近开发的新型低噪声多通道ASIC（专用集成电路）。BNL ASIC特别适合这种应用，因为它具有低噪声、电荷敏感型和峰值时间机制。此外，其他芯片规格也与硅光电二极管理想匹配。整体噪声系统水平的改进，以及使用硅ASIC和硅光电二极管提供的相对便宜的技术制造大面积阵列的能力，将导致具有改进的能量分辨率和改进的灵敏度的鲁棒伽马相机。改进的能量分辨率将直接导致更高的灵敏度、更好的对比度、改进的空间分辨率和执行SPECT图像的量化的能力。 在第一阶段，Photon Imaging将与BNL的工作人员密切合作，评估现有ASIC的性能，以及Photon一直在开发的用于与CsI（TI）闪烁体阵列耦合的新硅光电二极管。几个通道将在响应放射性同位素源的伽马辐射的特点。每个通道将收集完整的能量谱。将提出对芯片的修改，以在医学成像应用中获得最佳性能。在第二阶段，将根据第一阶段的评估，对芯片进行修改，以优化芯片的整形时间、模拟输出、增益和其他参数。第二阶段将包括设计、制造和表征改进的ASIC，以及完全制造由256通道读出的16x16阵列组成的原型探测器阵列。原型探测器阵列将使用放射性同位素源和医学成像体模进行评估。

DESCRIPTION (provided by applicant): We will develop a novel detector modules for a new class of solid state gamma cameras, offering superior performance compared with currently available systems, which will be capable of excellent energy resolution, good sensitivity down to 27 keV for small animal imaging applications and also the ability to clearly separate closely spaced higher energy gamma-rays for dual-isotope imaging applications. This new gamma camera technology will be based on Photon Imaging's new silicon photodiodes and a new low noise multi-channel ASIC (application specific integrated circuit), recently developed by scientists at the Brookhaven National Laboratory (BNL). The BNL ASIC is particularly well suited for this application due to its low noise, charge sensitive preamplifier, and peaking time regime. In addition, other chip specifications are ideally matched to the silicon photodiode. Improvements in the overall noise system level, and the ability to fabricate large area arrays using the relatively inexpensive technology afforded by the silicon ASIC and silicon photodiodes, will result in robust gamma cameras with improved energy resolution and improved sensitivity. Improved energy resolution will lead directly to higher sensitivity, better contrast, improved spatial resolution and the capability to perform quantification of SPECT images. In Phase I, Photon Imaging will work closely with BNL staff to evaluate the existing ASIC performance in conjunction with new silicon photodiodes that Photon has been developing for coupling with CsI(TI) scintillator arrays. Several channels will be characterized in response to gamma radiation from radioisotope sources. Full energy spectra will be collected per channel. Modifications for the chip will be proposed for optimum performance in medical imaging applications. In Phase II, the chip will be modified to optimize the chip with respect to shaping time, analog outputs, gain and other parameters based on the Phase I evaluation. Phase II will include design, fabrication and characterization of the modified ASIC, and full fabrication of a prototype detector array comprised of a 16x16 array for 256-channels of readout. The prototype detector array will be evaluated with radioisotope sources and medical imaging phantoms.