Evaluation of static physics performance of the jPET-D4 by Monte Carlo simulations
Evaluation of static physics performance of the jPET-D4 by Monte Carlo simulations
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DOI：
10.1088/0031-9155/52/1/014
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发表时间：
2007-01
影响因子：
3.5
通讯作者：
T. Hasegawa;E. Yoshida;Ayako Kobayashi;K. Shibuya;F. Nishikido;Tetsuya Kobayashi;M. Suga;T. Yamaya;K. Kitamura;K. Maruyama;H. Murayama
中科院分区：
文献类型：
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作者：
T. Hasegawa;E. Yoshida;Ayako Kobayashi;K. Shibuya;F. Nishikido;Tetsuya Kobayashi;M. Suga;T. Yamaya;K. Kitamura;K. Maruyama;H. Murayama
JPET-D4是第一款引入独特的四层相互作用深度(DOI)探测器方案的PET扫描仪，以实现高灵敏度和统一的高空间分辨率。本文对研制的PET扫描仪的静态物理性能进行了测量和蒙特卡罗模拟结果的比较。测量结果包括单能谱和符合能谱、点源和线源灵敏度、轴向灵敏度分布(切片分布)和散射分数。我们使用GATE(Geant4应用于层析发射)作为蒙特卡罗辐射输运模型。通过对DOI探测器的特性响应进行合理的假设，仿真模型较好地再现了实验结果。在之前的一项研究中，JPET-D4被证明提供了高达3毫米(FHWM)的统一空间分辨率。在本研究中，我们证明在视野中心提供了11.3±0.5%的高灵敏度。然而，大约四分之三的灵敏度与多晶体事件有关，对于这些事件，对晶体的一些错误识别是不可避免的。因此，开发一种更有效的方法来识别相互作用的晶体并减少误识别，以便同时利用这些高性能值是至关重要的。我们期望用更具吸收能力的晶体如BGO和LSO来代替GSO晶体来提高有效的灵敏度。我们在这里描述的结果对于充分利用具有DOI识别能力的下一代PET系统是必不可少的。
The jPET-D4 is the first PET scanner to introduce a unique four-layer depth-of-interaction (DOI) detector scheme in order to achieve high sensitivity and uniform high spatial resolution. This paper compares measurement and Monte Carlo simulation results of the static physics performance of this prototype research PET scanner. Measurement results include single and coincidence energy spectra, point and line source sensitivities, axial sensitivity profile (slice profile) and scatter fraction. We use GATE (Geant4 application for tomographic emission) as a Monte Carlo radiation transport model. Experimental results are reproduced well by the simulation model with reasonable assumptions on characteristic responses of the DOI detectors. In a previous study, the jPET-D4 was shown to provide a uniform spatial resolution as good as 3 mm (FHWM). In the present study, we demonstrate that a high sensitivity, 11.3 ± 0.5%, is provided at the FOV centre. However, about three-fourths of this sensitivity is related to multiple-crystal events, for which some misidentification of the crystal cannot be avoided. Therefore, it is crucial to develop a more efficient way to identify the crystal of interaction and to reduce misidentification in order to make use of these high performance values simultaneously. We expect that effective sensitivity can be improved by replacing the GSO crystals with more absorptive crystals such as BGO and LSO. The results we describe here are essential to take full advantage of the next generation PET systems that have DOI recognition capability.