Wang Qiang, Wen Jie, Ravindranath Bosky, O'Sullivan Andrew W, Catherall David, Li Ke, Wei Shouyi, Komarov Sergey, Tai Yuan-Chuan
Washington University in St Louis, MO 63110, USA.
Saint Louis University, St. Louis, MO 63103, USA.
Nucl Instrum Methods Phys Res A. 2015 Sep 11;794:151-159. doi: 10.1016/j.nima.2015.04.071.
Compact high-resolution panel detectors using virtual pinhole (VP) PET geometry can be inserted into existing clinical or pre-clinical PET systems to improve regional spatial resolution and sensitivity. Here we describe a compact panel PET detector built using the new Though Silicon Via (TSV) multi-pixel photon counters (MPPC) detector. This insert provides high spatial resolution and good timing performance for multiple bio-medical applications. Because the TSV MPPC design eliminates wire bonding and has a package dimension which is very close to the MPPC's active area, it is 4-side buttable. The custom designed MPPC array (based on Hamamatsu S12641-PA-50(x)) used in the prototype is composed of 4 × 4 TSV-MPPC cells with a 4.46 mm pitch in both directions. The detector module has 16 × 16 lutetium yttrium oxyorthosilicate (LYSO) crystal array, with each crystal measuring 0.92 × 0.92 × 3 mm with 1.0 mm pitch. The outer diameter of the detector block is 16.8 × 16.8 mm. Thirty-two such blocks will be arranged in a 4 × 8 array with 1 mm gaps to form a panel detector with detection area around 7 cm × 14 cm in the full-size detector. The flood histogram acquired with Ge-68 source showed excellent crystal separation capability with all 256 crystals clearly resolved. The detector module's mean, standard deviation, minimum (best) and maximum (worst) energy resolution were 10.19%, +/-0.68%, 8.36% and 13.45% FWHM, respectively. The measured coincidence time resolution between the block detector and a fast reference detector (around 200 ps single photon timing resolution) was 0.95 ns. When tested with Siemens Cardinal electronics the performance of the detector blocks remain consistent. These results demonstrate that the TSV-MPPC is a promising photon sensor for use in a flat panel PET insert composed of many high resolution compact detector modules.
采用虚拟针孔（VP）正电子发射断层扫描（PET）几何结构的紧凑型高分辨率平板探测器可插入现有的临床或临床前PET系统，以提高区域空间分辨率和灵敏度。在此，我们描述一种使用新型硅通孔（TSV）多像素光子计数器（MPPC）探测器构建的紧凑型平板PET探测器。该插件为多种生物医学应用提供了高空间分辨率和良好的定时性能。由于TSV MPPC设计消除了引线键合，且封装尺寸非常接近MPPC的有源区，因此它可以四面拼接。原型中使用的定制设计MPPC阵列（基于滨松S12641-PA-50(x)）由4×4个TSV-MPPC单元组成，两个方向的间距均为4.46毫米。探测器模块有16×16的正硅酸镥钇（LYSO）晶体阵列，每个晶体尺寸为0.92×0.92×3毫米，间距为1.0毫米。探测器模块的外径为16.8×16.8毫米。32个这样的模块将以1毫米的间隙排列成4×8阵列，以形成一个全尺寸探测器中探测面积约为7厘米×14厘米的平板探测器。用锗-68源获取的泛洪直方图显示出出色的晶体分离能力，所有256个晶体都能清晰分辨。探测器模块的平均、标准偏差、最小（最佳）和最大（最差）能量分辨率分别为10.19%、±0.68%、8.36%和13.45%半高宽（FWHM）。在块探测器与快速参考探测器（单光子定时分辨率约为200皮秒）之间测得的符合时间分辨率为0.95纳秒。当使用西门子Cardinal电子设备进行测试时，探测器模块的性能保持一致。这些结果表明，TSV-MPPC是一种有前景的光子传感器，可用于由许多高分辨率紧凑型探测器模块组成的平板PET插件。
