基于碲锌镉探测器的高分辨率小动物正电子发射断层显像研究

项目名称： 基于碲锌镉探测器的高分辨率小动物正电子发射断层显像研究

项目编号： No.11305083

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 尹永智

作者单位： 兰州大学

项目金额： 30万元

中文摘要： 正电子发射断层显像（PET），包括人体和小动物成像，已经广泛应用于疾病诊断、药物研究、基因表达等各个方面。特别是小动物PET的图像分辨率已经接近或好于1毫米。当前，PET以闪烁体和光电倍增管耦合作为伽玛射线探测器，其体积较大，空间分辨率难以继续提高。在亚毫米分辨率小动物PET成像中，碲锌镉半导体探测器是正在研究的替代探测器之一，它可在室温下使用，拥有极高的能量分辨率、良好的空间分辨率、较高的伽玛射线阻止本领等优点。像素碲锌镉探测器的空间分辨率可以通过蒸镀极小尺寸的像素电极来得以提高，从根本上解决了切割极小闪烁晶体阵列的困难。本项目拟以600微米的像素碲锌镉探测器和高密度ASIC读出电子学系统为基础，结合一套64路PXI数据获取系统，设计开发亚毫米分辨率的小动物PET显像装置。亚毫米分辨率PET显像装置的研发将使小动物成像的质量有实质性的提高，在小动物PET/CT、PET/MR等成像仪器的开发中起到关键作用。

中文关键词： 正电子发射断层显像；碲锌镉探测器；硅酸钇镥探测器；空间分辨率；电荷共享

英文摘要： Positron Emission Tomography (PET) has been widely used in clinical diagnosis, animal research, and gene expression. The State-of-the-art image resolution of small-animal PET scanner has been close to 1 mm. Several groups developed PET insert devices or Probes to improve the image resolution of regions of interest, and they obtained super high-resolution small-animal PET image. In this project, we will setup a small-animal PET prototype by using Cadmium Zinc Telluride (CdZnTe) detector as insert devices. The goal is to push the image resolution of local regions to sub-millimeter. CdZnTe detector is a potential candidate for medical imaging applications due to its high energy resolution, high spatial resolution, and relatively-high atomic number. Using single polarity charge sensing configurations, for instance pixelated detector, the energy resolution of CdZnTe detector could be close to 2% FWHM at 511keV, and the spatial resolution could be better than 1mm. Such kind of CdZnTe detectors may allow one to improve image resolution and to further reject scatter events for PET imaging applications. In this work, 20mm × 20mm × 10mm CdZnTe substrate will be fabricated with 600μm pixels (500μm anode pixel with 100μm gap) and coplanar cathode. CdZnTe signals will be processed by multiple-channel ASIC readout electronics

英文关键词： Positron Emission Tomography；CdZnTe detectors；LYSO detectors；Spatial resolution；Charge sharing