Development of a simplified simulation model for performance characterization of a pixellated CdZnTe multimodality imaging system
Development of a simplified simulation model for performance characterization of a pixellated CdZnTe multimodality imaging system
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DOI：
10.1088/0031-9155/53/4/019
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发表时间：
2008-02-21
影响因子：
3.5
通讯作者：
Darambara, D. G.
中科院分区：
文献类型：
--
作者：
Guerra, P.;Santos, A.;Darambara, D. G.
分子成像的当前要求导致互补模态在单个混合成像系统中的完全集成，以关联功能和结构。在各种现有的检测器技术中，其可以被实现为将核模态（PET和/或单光子发射计算机断层摄影与X射线（CT）以及最可能与MR集成，像素化宽带隙室温半导体检测器（诸如CdZnTe和/或CdTe）是有希望的候选者。本文论述了像素化半导体辐射探测器的简化仿真模型的发展，作为第一步的多模态成像系统的性能表征的基础上CdZnTe。特别是，这项工作提出了一个简单的计算模型，基于Schockley - Ramo定理的1D近似解，并将其集成到Geant 4断层扫描发射（GATE）平台的应用程序中，以便准确地执行，因此，提高了不同配置的像素化探测器的模拟，同时进行阴极和阳极像素读出。这里提出的模型成功地验证了现有的详细的有限元模拟器，多几何模拟代码，在阳极处感应的电荷，考虑到像素间电荷共享和串扰，以及检测器电荷感应效率。作为最后一点，该模型提供了估计的能量谱和时间分辨率的Co-57和F-18源获得的GATE代码后，合并所提出的模型。
Current requirements of molecular imaging lead to the complete integration of complementary modalities in a single hybrid imaging system to correlate function and structure. Among the various existing detector technologies, which can be implemented to integrate nuclear modalities ( PET and/ or singlephoton emission computed tomography with x- rays ( CT) and most probably with MR, pixellated wide bandgap room temperature semiconductor detectors, such as CdZnTe and/ or CdTe, are promising candidates. This paper deals with the development of a simplified simulation model for pixellated semiconductor radiation detectors, as a first step towards the performance characterization of a multimodality imaging system based on CdZnTe. In particular, this work presents a simple computational model, based on a 1D approximate solution of the Schockley - Ramo theorem, and its integration into the Geant4 application for tomographic emission ( GATE) platform in order to perform accurately and, therefore, improve the simulations of pixellated detectors in different configurations with a simultaneous cathode and anode pixel readout. The model presented here is successfully validated against an existing detailed finite element simulator, the multi- geometry simulation code, with respect to the charge induced at the anode, taking into consideration interpixel charge sharing and crosstalk, and to the detector charge induction efficiency. As a final point, the model provides estimated energy spectra and time resolution for Co-57 and F-18 sources obtained with the GATE code after the incorporation of the proposed model.