Redesign of the GATE PET coincidence sorter
Redesign of the GATE PET coincidence sorter
复制标题
DOI：
10.1088/0031-9155/61/18/n522
复制
发表时间：
2016-09-21
影响因子：
3.5
通讯作者：
Buvat, Irene
中科院分区：
文献类型：
--
作者：
Strydhorst, Jared;Buvat, Irene
GATE软件平台基于Geant4工具包，用于模拟粒子与物质的相互作用，可以模拟其他医学成像和治疗系统，如正电子发射断层扫描。然而，至少有一篇出版物(Moraes et al . 2015 Phys。Med. 31 43-8)报告了预期结果与使用GATE模拟获得的结果之间的差异，特别是在处理扫描仪检测到的单个事件以找到巧合对的巧合排序器方面。特别是，当前的软件在多窗口模式下似乎高估了“真实”巧合对的数量，而用于估计提示巧合窗口中存在的随机性的延迟巧合窗口则低估了随机性。这两种效果在高计数率时尤为明显。我们调查了这一差异，并重现了报告的问题。我们也重写了GATE代码的相关部分来纠正这个问题。在这篇笔记中，我们描述了对巧合分类器的修改，并重复了先前显示意想不到结果的模拟。由于算法本身的原因，单窗模式下的随机估计仍然存在一些差异。然而，在多窗口模式下，仿真结果与预期结果完全一致。对巧合分类器代码的修改将被纳入GATE的下一个版本（>版本7.2）。
The GATE software platform, based on the Geant4 toolkit for simulating particle interactions with matter, enables simulation of, among other medical imaging and treatment systems, positron emission tomography. However, at least one publication (Moraes et al 2015 Phys. Med. 31 43-8) has reported discrepancies between the expected results and those obtained using GATE simulations, specifically with respect to the coincidence sorter which processes single events detected by the scanner to find coincidence pairs. In particular, the current software appears to overestimate the number of 'true' coincidence pairs when in multi-window mode, while the delayed coincidence window, used to estimate the randoms present in the prompt coincidence window, underestimates the randoms. Both effects are particularly evident at high count rates. We have investigated this discrepancy and reproduced the reported problems. We have also rewritten the relevant portion of the GATE code to correct the issue. In this note we describe the modifications to the coincidence sorter and repeat the simulations which previously showed unexpected results. Some discrepancies remain in the estimation of the randoms with the single-window mode which are a consequence of the algorithm itself. In multi-window mode however, the simulation agrees exactly with the expected results. The modifications to the coincidence sorter code will be incorporated into the next release of GATE (>version 7.2).