Positron range estimations with PeneloPET
Positron range estimations with PeneloPET
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DOI：
10.1088/0031-9155/58/15/5127
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发表时间：
2013-08-07
影响因子：
3.5
通讯作者：
Udias, J. M.
中科院分区：
文献类型：
--
作者：
Cal-Gonzalez, J.;Herraiz, J. L.;Udias, J. M.
朝向高分辨率PET成像的技术进步试图克服空间分辨率的固有物理限制。正电子在组织中行进，直到它们湮灭成检测到的两个伽马光子。该范围是对PET成像模糊的主要探测器无关贡献。在很大程度上，它可以补救在图像重建过程中，如果准确估计的正电子范围是可用的。然而，现有的估计不同，并与稀缺的实验数据的比较是不确定的。在这项工作中，我们提出了正电子湮没分布从Monte Carlo模拟与PeneloPET模拟工具包，几种常见的PET同位素（F-18，C-11，N-13，O-15，Ga-68和Rb-82）在不同的生物介质（皮质骨，软骨，皮肤，肌肉横纹，脑，水，脂肪组织和肺）。我们将PeneloPET模拟与文献中的实验数据和其他模拟结果进行比较。为此，在文献中采用的不同的正电子射程表示是相互关联的正电子射程剖面的一个新的参数化。我们的研究结果与实验结果基本一致，并且与之前报道的大多数模拟结果一致，平均值和最大范围值的差异小于20%。从这些结果中，我们得出结论，需要更好的实验测量，特别是解开在正电子范围内的正电子素形成的影响。最后，在PeneloPET的帮助下，我们证实，缩放方法可以用来获得通用的，材料和同位素独立的，正电子距离分布，这将大大简化距离校正。
Technical advances towards high resolution PET imaging try to overcome the inherent physical limitations to spatial resolution. Positrons travel in tissue until they annihilate into the two gamma photons detected. This range is the main detector-independent contribution to PET imaging blurring. To a large extent, it can be remedied during image reconstruction if accurate estimates of positron range are available. However, the existing estimates differ, and the comparison with the scarce experimental data available is not conclusive. In this work we present positron annihilation distributions obtained from Monte Carlo simulations with the PeneloPET simulation toolkit, for several common PET isotopes (F-18, C-11, N-13, O-15, Ga-68 and Rb-82) in different biological media (cortical bone, soft bone, skin, muscle striated, brain, water, adipose tissue and lung). We compare PeneloPET simulations against experimental data and other simulation results available in the literature. To this end the different positron range representations employed in the literature are related to each other by means of a new parameterization for positron range profiles. Our results are generally consistent with experiments and with most simulations previously reported with differences of less than 20% in the mean and maximum range values. From these results, we conclude that better experimental measurements are needed, especially to disentangle the effect of positronium formation in positron range. Finally, with the aid of PeneloPET, we confirm that scaling approaches can be used to obtain universal, material and isotope independent, positron range profiles, which would considerably simplify range correction.