A theoretical framework to predict the most likely ion path in particle imaging
A theoretical framework to predict the most likely ion path in particle imaging
复制标题
DOI：
10.1088/1361-6560/aa58ce
复制
发表时间：
2017-03-07
影响因子：
3.5
通讯作者：
Seco, Joao
中科院分区：
文献类型：
--
作者：
Collins-Fekete, Charles-Antoine;Volz, Lennart;Seco, Joao
在这项工作中，引入了一种通用的严格贝叶斯公式来预测任何离子在两个检测点之间穿过介质的最可能路径。根据粒子在材料中的散射以及对其初始和最终位置、方向和能量的测量来预测路径。将路径估计的精度与蒙特卡罗模拟的路径进行了比较。从氢到碳的每个离子都在两种情况下进行模拟，(1)范围固定，(2)初始速度固定。在范围保持不变的情况下，估计路径和蒙特卡罗路径之间的最大均方根误差在质子路径估计(0.50 mm)和氦路径估计(0.18 mm)之间显著下降，但在碳路径估计(0.09 mm)之前下降较小。然而，这种情况被确定为在最小化路径分辨率的同时最大化剂量的配置。在初始速度固定的情况下，估计路径和蒙特卡罗路径之间的最大均方根误差在质子路径估计(0.29 mm)和氦路径估计(0.09 mm)之间显著下降，但对于较重的离子到碳(0.12 mm)，则增加。结果，氦被发现是最低剂量下路径估计最准确的粒子，有可能导致更高空间分辨率的断层图像。
In this work, a generic rigorous Bayesian formalism is introduced to predict the most likely path of any ion crossing a medium between two detection points. The path is predicted based on a combination of the particle scattering in the material and measurements of its initial and final position, direction and energy. The path estimate's precision is compared to the Monte Carlo simulated path. Every ion from hydrogen to carbon is simulated in two scenarios, (1) where the range is fixed and (2) where the initial velocity is fixed. In the scenario where the range is kept constant, the maximal root-mean- square error between the estimated path and the Monte Carlo path drops significantly between the proton path estimate (0.50 mm) and the helium path estimate (0.18 mm), but less so up to the carbon path estimate (0.09 mm). However, this scenario is identified as the configuration that maximizes the dose while minimizing the path resolution. In the scenario where the initial velocity is fixed, the maximal root-mean-square error between the estimated path and the Monte Carlo path drops significantly between the proton path estimate (0.29 mm) and the helium path estimate (0.09 mm) but increases for heavier ions up to carbon (0.12 mm). As a result, helium is found to be the particle with the most accurate path estimate for the lowest dose, potentially leading to tomographic images of higher spatial resolution.