Park Ryeojin, Miller Brian W, Jha Abhinav K, Furenlid Lars R, Hunter William C J, Barrett Harrison H
Department of Medical Imaging, University of Arizona, Tucson, AZ, 85724 USA. They are also with the College of Optical Sciences, University of Arizona, Tucson, AZ 85721 USA.
Department of Radiology, University of Arizona, Tucson, AZ 85724 USA and is now appointed in Pacific Northwest National Laboratory, Radiation Detection and Nuclear Sciences Group, National Security Directorate, Richland, WA 99352 USA.
IEEE Nucl Sci Symp Conf Rec (1997). 2012 Oct-Nov;2012:2123-2127. doi: 10.1109/NSSMIC.2012.6551486.
We have designed and are developing a novel proof-of-concept PET system called BazookaPET. In order to complete the PET configuration, at least two detector elements are required to detect positron-electron annihilation events. Each detector element of the BazookaPET has two independent data acquisition channels. One side of the scintillation crystal is optically coupled to a 4×4 silicon photomultiplier (SiPM) array and the other side is a CCD-based gamma camera. Using these two separate channels, we can obtain data with high energy, temporal and spatial resolution data by associating the data outputs via several maximum-likelihood estimation (MLE) steps. In this work, we present the concept of the system and the prototype detector element. We focus on characterizing individual detector channels, and initial experimental calibration results are shown along with preliminary performance-evaluation results. We measured energy resolution and the integrated traces of the slit-beam images from both detector channel outputs. A photo-peak energy resolution of ~5.3% FWHM was obtained from the SiPM and ~48% FWHM from the CCD at 662 keV. We assumed SiPM signals follow Gaussian statistics and estimated the 2D interaction position using MLE. Based on our the calibration experiments, we computed the Cramér-Rao bound (CRB) for the SiPM detector channel and found that the CRB resolution is better than 1 mm in the center of the crystal.
我们设计并正在开发一种名为BazookaPET的新型概念验证正电子发射断层扫描（PET）系统。为了完成PET配置，至少需要两个探测器元件来检测正电子 - 电子湮灭事件。BazookaPET的每个探测器元件都有两个独立的数据采集通道。闪烁晶体的一侧与一个4×4硅光电倍增管（SiPM）阵列进行光学耦合，另一侧是基于电荷耦合器件（CCD）的伽马相机。通过这两个独立的通道，我们可以通过几个最大似然估计（MLE）步骤关联数据输出，从而获得具有高能量、时间和空间分辨率的数据。在这项工作中，我们介绍了该系统的概念和原型探测器元件。我们专注于对各个探测器通道进行特性描述，并展示了初始实验校准结果以及初步性能评估结果。我们测量了来自两个探测器通道输出的狭缝束图像的能量分辨率和积分轨迹。在662keV时，从SiPM获得的光峰能量分辨率约为5.3%半高宽（FWHM），从CCD获得的约为48%FWHM。我们假设SiPM信号遵循高斯统计，并使用MLE估计二维相互作用位置。基于我们的校准实验，我们计算了SiPM探测器通道的克拉美 - 罗界（CRB），发现晶体中心的CRB分辨率优于1mm。
