Pickford Scienti Oliver L P, Bamber Jeffrey C, Darambara Dimitra G
Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London SM2 5NG, UK.
Sensors (Basel). 2020 Oct 27;20(21):6093. doi: 10.3390/s20216093.
Most modern energy resolving, photon counting detectors employ small (sub 1 mm) pixels for high spatial resolution and low per pixel count rate requirements. These small pixels can suffer from a range of charge sharing effects (CSEs) that degrade both spectral analysis and imaging metrics. A range of charge sharing correction algorithms (CSCAs) have been proposed and validated by different groups to reduce CSEs, however their performance is often compared solely to the same system when no such corrections are made. In this paper, a combination of Monte Carlo and finite element methods are used to compare six different CSCAs with the case where no CSCA is employed, with respect to four different metrics: absolute detection efficiency, photopeak detection efficiency, relative coincidence counts, and binned spectral efficiency. The performance of the various CSCAs is explored when running on systems with pixel pitches ranging from 100 µm to 600µm, in 50 µm increments, and fluxes from 10 to 10 photons mm s are considered. Novel mechanistic explanations for the difference in performance of the various CSCAs are proposed and supported. This work represents a subset of a larger project in which pixel pitch, thickness, flux, and CSCA are all varied systematically.
大多数现代能量分辨光子计数探测器采用小尺寸（小于1毫米）像素，以实现高空间分辨率和低每像素计数率要求。这些小像素可能会受到一系列电荷共享效应（CSEs）的影响，从而降低光谱分析和成像指标。不同的研究团队已经提出并验证了一系列电荷共享校正算法（CSCAs），以减少CSEs，然而，它们的性能通常仅与未进行此类校正的同一系统进行比较。在本文中，结合蒙特卡罗方法和有限元方法，针对四种不同的指标：绝对探测效率、光电峰探测效率、相对符合计数和分箱光谱效率，将六种不同的CSCAs与未采用CSCA的情况进行比较。在像素间距从100微米到600微米、以50微米为增量的系统上运行时，探讨了各种CSCAs的性能，并考虑了从10到10光子/毫米²/秒的通量。针对各种CSCAs性能差异提出并支持了新的机理解释。这项工作是一个更大项目的一部分，在该项目中，像素间距、厚度、通量和CSCA都进行了系统变化。
