Several direct algorithms have been proposed to take into account the non-linear path of protons in the reconstruction of a proton CT (pCT) image. This paper presents a comparison between five of them, in terms of spatial resolution and relative stopping power (RSP) accuracy. Our comparison includes (1) a distance-driven algorithm extending the filtered backprojection to non-linear trajectories (DD), (2) an algorithm reconstructing a pCT image from optimized projections (ML), (3) a backproject-then-filter approach using a 2D cone filter (BTF), (4) a differentiated backprojection algorithm based on the inversion of the Hilbert transform (DBP), and (5) an algorithm using a 2D directional ramp filter (DR). We have simulated a single tracking pCT set-up using Geant4 through GATE, with a proton source and two position, direction and energy detectors upstream and downstream from the object. Tracker uncertainties were added on the position and direction measurements. A Catphan 528 phan...

中文翻译：

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质子计算机断层扫描中直接重建算法的比较。

已经提出了几种直接算法，以在质子CT（pCT）图像的重建中考虑质子的非线性路径。本文在空间分辨率和相对停止功率（RSP）精度方面对其中五个进行了比较。我们的比较包括（1）距离驱动算法，将滤波后的反投影扩展到非线性轨迹（DD），（2）从优化投影（ML）重构pCT图像的算法，（3）反投影-然后-滤波方法使用2D圆锥滤波器（BTF），（4）基于Hilbert变换（DBP）反演的差分反投影算法，以及（5）使用2D定向斜坡滤波器（DR）的算法。我们使用Geant4到GATE模拟了一个单跟踪pCT设置，其中有一个质子源和两个位置，物体上游和下游的方向和能量探测器。跟踪器的不确定性被添加到位置和方向测量中。Catphan 528幻影...