The impact of secondary fragments on the image quality of helium ion imaging.
The impact of secondary fragments on the image quality of helium ion imaging.
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DOI：
10.1088/1361-6560/aadf25
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发表时间：
2018-10-02
影响因子：
3.5
通讯作者：
Seco J
中科院分区：
文献类型：
--
作者：
Volz L;Piersimoni P;Bashkirov VA;Brons S;Collins-Fekete CA;Johnson RP;Schulte RW;Seco J
单粒子离子成像能够直接重建离子束治疗所需的相对阻止本领（RSP）信息。氦离子最近被假设为这种技术的最佳物种。这项工作的目的是调查二次碎片的氦CT（HeCT）的图像质量的影响，并评估的性能的原型质子CT（pCT）扫描仪操作时，与氦束在蒙特卡罗模拟和实验。在海德堡离子束治疗中心（HIT）安装美国pCT联盟原型扫描仪进行实验。使用TOPAS工具包用扫描仪进行模拟。针对圆柱形水体模、CTP 404（感光测定）和CTP 528（线对）Catphan®模块重建HeCT图像。为了识别和消除由碎裂引起的个别事件，扫描仪的多级能量探测器被改装成Δ E-E望远镜。所开发的滤波器的使用消除了HeCT重建图像中另外出现的环形伪影。对于水模型的HeCT重建图像，最大RSP误差在模拟中相对于未滤波图像提高了几乎8倍，在实验中提高了10倍。类似地，对于CTP 404模块，当应用滤波器时，平均RSP精度在模拟和实验中均提高了6倍（平均相对误差在模拟中为0.40%，在实验中为0.45%）。在通过CTP 528模块进行的空间分辨率评估中，滤波器的主要效果是降噪。模拟图像和实验图像的空间分辨率均为104 lp/cm。总之，新的过滤器开发的二次碎片被证明是有效的，在改善重建图像的视觉质量和RSP精度。使用滤波器，pCT扫描仪能够进行精确的HeCT成像。
Single-event ion imaging enables the direct reconstruction of the relative stopping power (RSP) information required for ion-beam therapy. Helium ions were recently hypothesized to be the optimal species for such technique. The purpose of this work is to investigate the effect of secondary fragments on the image quality of helium CT (HeCT) and to assess the performance of a prototype proton CT (pCT) scanner when operated with helium beams in Monte Carlo simulations and experiment. Experiments were conducted installing the U.S. pCT consortium prototype scanner at the Heidelberg Ion-Beam Therapy Center (HIT). Simulations were performed with the scanner using the TOPAS toolkit. HeCT images were reconstructed for a cylindrical water phantom, the CTP404 (sensitometry), and the CTP528 (line-pair) Catphan® modules. To identify and remove individual events caused by fragmentation, the multistage energy detector of the scanner was adapted to function as a ΔE − E telescope. The use of the developed filter eliminated the otherwise arising ring artifacts in the HeCT reconstructed images. For the HeCT reconstructed images of a water phantom, the maximum RSP error was improved by almost a factor 8 with respect to unfiltered images in the simulation and a factor 10 in the experiment. Similarly, for the CTP404 module, the mean RSP accuracy improved by a factor 6 in both the simulation and the experiment when the filter was applied (mean relative error 0.40% in simulation, 0.45% in experiment). In the evaluation of the spatial resolution through the CTP528 module, the main effect of the filter was noise reduction. For both simulated and experimental images the spatial resolution was ∼4lp/cm. In conclusion, the novel filter developed for secondary fragments proved to be effective in improving the visual quality and RSP accuracy of the reconstructed images. With the filter, the pCT scanner is capable of accurate HeCT imaging.
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影响因子：
3.5
作者：
Collins-Fekete, Charles-Antoine;Volz, Lennart;Seco, Joao
通讯作者：
Seco, Joao
影响因子：
3.5
作者：
Doolan, P. J.;Collins-Fekete, Charles-Antoine;Seco, Joao
通讯作者：
Seco, Joao
DOI：
10.1016/j.nima.2017.06.046
发表时间：
2017-10-11
影响因子：
1.4
作者：
Bolst, David;Cirrone, Giuseppe A. P.;Guatelli, Susanna
通讯作者：
Guatelli, Susanna
影响因子：
3.8
作者：
Giacometti, Valentina;Bashkirov, Vladimir A.;Schulte, Reinhard W.
通讯作者：
Schulte, Reinhard W.
影响因子：
4.4
作者：
GOLDHABER, AS
通讯作者：
GOLDHABER, AS