Optimal whole-body PET scanner configurations for different volumes of LSO scintillator: a simulation study.
Optimal whole-body PET scanner configurations for different volumes of LSO scintillator: a simulation study.
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DOI：
10.1088/0031-9155/57/13/4077
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发表时间：
2012-07-07
影响因子：
3.5
通讯作者：
Badawi RD
中科院分区：
文献类型：
--
作者：
Poon JK;Dahlbom ML;Moses WW;Balakrishnan K;Wang W;Cherry SR;Badawi RD
当前一代临床全身PET扫描仪的轴向视野(AFOV)范围为15-22厘米，这限制了灵敏度，并使全身动态成像或全身细胞跟踪研究中非常低活动的成像等应用几乎不可能。一般而言，扩展AFOV显著提高了灵敏度和计数率性能。然而，在保持探测器厚度的同时延长AFOV具有显著的成本影响。此外，随着AFOV的增加，随机重合、探测器停滞时间和对象衰减可能会降低扫描仪的性能。在本文中，我们使用蒙特卡罗模拟来寻找最佳的扫描器几何形状(即AFOV、探测器厚度和接受角)，其基于计数率性能，范围从10到90 L，探测器厚度从5到20 mm变化。我们将结果与基于当前西门子Biograph MCT几何和电子学的扫描仪的性能进行了比较。我们的模拟模型是基于西门子Bioggraph MCT的单个组件开发的，并使用NEMA NU-2 2007计数率协议根据实验数据进行了验证。在这项研究中，对于每种扫描仪配置，使用直径27厘米、均匀填充200厘米的圆柱形体模，计算作为最大环差(即接受角度)和活动浓度的函数的噪声当量计数率(NECR)。为了减少随机重合的影响，我们实现了基于响应线长度的可变重合时间窗口，与对最大环差值较大的扫描仪使用静态重合时间窗口相比，NECR性能提高了10%。对于给定的闪烁体体积，与最短且探测器最厚的AFOV扫描仪相比，最佳配置可带来高达16%的适度计数率性能提升。然而，最长的AFOV约为2米，探测器厚度为20 mm，与当前的西门子Biograph MCT扫描仪配置相比，NECR提高了25-31倍。
The axial field of view (AFOV) of the current generation of clinical whole-body PET scanners range from 15–22 cm, which limits sensitivity and renders applications such as whole-body dynamic imaging, or imaging of very low activities in whole-body cellular tracking studies, almost impossible. Generally, extending the AFOV significantly increases the sensitivity and count-rate performance. However, extending the AFOV while maintaining detector thickness has significant cost implications. In addition, random coincidences, detector dead time, and object attenuation may reduce scanner performance as the AFOV increases. In this paper, we use Monte Carlo simulations to find the optimal scanner geometry (i.e. AFOV, detector thickness and acceptance angle) based on count-rate performance for a range of scintillator volumes ranging from 10 to 90 l with detector thickness varying from 5 to 20 mm. We compare the results to the performance of a scanner based on the current Siemens Biograph mCT geometry and electronics. Our simulation models were developed based on individual components of the Siemens Biograph mCT and were validated against experimental data using the NEMA NU-2 2007 count-rate protocol. In the study, noise-equivalent count rate (NECR) was computed as a function of maximum ring difference (i.e. acceptance angle) and activity concentration using a 27 cm diameter, 200 cm uniformly filled cylindrical phantom for each scanner configuration. To reduce the effect of random coincidences, we implemented a variable coincidence time window based on the length of the lines of response, which increased NECR performance up to 10% compared to using a static coincidence time window for scanners with large maximum ring difference values. For a given scintillator volume, the optimal configuration results in modest count-rate performance gains of up to 16% compared to the shortest AFOV scanner with the thickest detectors. However, the longest AFOV of approximately 2 m with 20 mm thick detectors resulted in performance gains of 25–31 times higher NECR relative to the current Siemens Biograph mCT scanner configuration.
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DOI：
10.1016/j.nima.2007.05.145
发表时间：
2007-09-21
影响因子：
1.4
作者：
Couceiro, M.;Ferreira, N. C.;Fonte, P.
通讯作者：
Fonte, P.
影响因子：
1.8
作者：
Kapusta, M;Szupryczynski, P;Syntfeld, A
通讯作者：
Syntfeld, A
DOI：
10.1007/s00259-003-1444-2
发表时间：
2004-06-01
影响因子：
9.1
作者：
Bettinardi, V;Danna, M;Fazio, F
通讯作者：
Fazio, F
影响因子：
1.8
作者：
Dahlbom, M;Schiepers, C;Czernin, J
通讯作者：
Czernin, J
DOI：
10.1007/s002590050474
发表时间：
1999-11-01
期刊：
EUROPEAN JOURNAL OF NUCLEAR MEDICINE
影响因子：
--
作者：
Cook, GJR;Lodge, MA;Fogelman, I
通讯作者：
Fogelman, I