David S, Georgiou M, Fysikopoulos E, Loudos G
Department of Biomedical Engineering, Technological Educational Institute of Athens, Athens, Greece.
Department of Biomedical Engineering, Technological Educational Institute of Athens, Athens, Greece; Department of Medical School, University of Thessaly, Larissa, Greece.
Phys Med. 2015 Nov;31(7):763-6. doi: 10.1016/j.ejmp.2015.03.008. Epub 2015 Apr 4.
In this study, we present the results of the evaluation of the SensL ArraySL-4 photo-detector, coupled to a 6 × 6 GAGG:Ce scintillator array, with 2 × 2 × 5 mm(3) crystal size elements for possible applications in medical imaging detectors with focus in PET applications. Experimental evaluation was carried out with (22)Na and (137)Cs radioactive sources and the parameters studied were energy resolution and peak to valley ratio.
ArraySL-4 is a commercially available, 4 × 4 array detector covering an active area of 13.4 mm(2). The GAGG:Ce scintillator array used in this study has 0.1 mm thickness BaSO4 reflector material between the crystal elements. A symmetric resistive voltage division matrix was applied, which reduces the 16 outputs of the array to 4 position signals. A Field Programmable Gate Array was used for triggering and digital processing of the signal pulses acquired using free running Analog to Digital Converters.
Raw images and horizontal profiles of the 6 × 6 GAGG:Ce scintillator array produced under 511 keV and 662 keV excitation are illustrated. Moreover, the energy spectra obtained with (22)Na and (137)Cs radioactive sources from a single 2 × 2 × 5 mm(3) GAGG:Ce scintillator are shown. The peak to valley ratio and the mean energy resolution values are reported.
The acquired raw image of the GAGG:Ce crystal array under 511 keV excitation shows a clear visualization of all discrete scintillator elements with a mean peak to valley ratio equal to 40. The mean energy resolution was measured equal to 10.5% and 9% respectively under 511 keV and 662 keV irradiation.
在本研究中，我们展示了将SensL ArraySL - 4光电探测器与6×6 GAGG:Ce闪烁体阵列耦合的评估结果，该闪烁体阵列的晶体尺寸为2×2×5 mm³，旨在用于医学成像探测器，重点是正电子发射断层扫描（PET）应用。使用²²Na和¹³⁷Cs放射性源进行了实验评估，研究的参数为能量分辨率和峰谷比。
ArraySL - 4是一种商用的4×4阵列探测器，有效面积为13.4 mm²。本研究中使用的GAGG:Ce闪烁体阵列在晶体元件之间有0.1 mm厚的硫酸钡反射材料。应用了对称电阻分压矩阵，将阵列的16个输出减少为4个位置信号。使用现场可编程门阵列（Field Programmable Gate Array）对通过自由运行的模数转换器采集的信号脉冲进行触发和数字处理。
展示了在511 keV和662 keV激发下产生的6×6 GAGG:Ce闪烁体阵列的原始图像和水平剖面图。此外，还展示了从单个2×2×5 mm³ GAGG:Ce闪烁体获得的²²Na和¹³⁷Cs放射性源的能谱。报告了峰谷比和平均能量分辨率值。
在511 keV激发下获得的GAGG:Ce晶体阵列的原始图像清晰显示了所有离散的闪烁体元件，平均峰谷比为40。在511 keV和662 keV辐照下测得的平均能量分辨率分别为10.5%和9%。
