{"title":"提高工业直线加速器成像质量的优化滤波器设计方法。","authors":"Gang Chen, Zehuan Zhang, Shuo Xu, Shibo Jiang, Ximing Liu, Peng Tang, Songyuan Li, Xincheng Xiang","doi":"10.3233/XST-240032","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>The polychromatic X-rays generated by a linear accelerator (Linac) often result in noticeable hardening artifacts in images, posing a significant challenge to accurate defect identification. To address this issue, a simple yet effective approach is to introduce filters at the radiation source outlet. However, current methods are often empirical, lacking scientifically sound metrics.</p><p><strong>Objective: </strong>This study introduces an innovative filter design method that optimizes filter performance by balancing the impact of ray intensity and energy on image quality.</p><p><strong>Materials and methods: </strong>Firstly, different spectra under various materials and thicknesses of filters were obtained using GEometry ANd Tracking (Geant4) simulation. Subsequently, these spectra and their corresponding incident photon counts were used as input sources to generate different reconstructed images. By comprehensively comparing the intensity differences and noise in images of defective and non-defective regions, along with considering hardening indicators, the optimal filter was determined.</p><p><strong>Results: </strong>The optimized filter was applied to a Linac-based X-ray computed tomography (CT) detection system designed for identifying defects in graphite materials within high-temperature gas-cooled reactor (HTR), with defect dimensions of 2 mm. After adding the filter, the hardening effect reduced by 22%, and the Defect Contrast Index (DCI) reached 3.226.</p><p><strong>Conclusion: </strong>The filter designed based on the parameters of Average Difference (AD) and Defect Contrast Index (DCI) can effectively improve the quality of defect images.</p>","PeriodicalId":49948,"journal":{"name":"Journal of X-Ray Science and Technology","volume":" ","pages":"1137-1150"},"PeriodicalIF":1.7000,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"An optimized filter design approach for enhancing imaging quality in industrial linear accelerator.\",\"authors\":\"Gang Chen, Zehuan Zhang, Shuo Xu, Shibo Jiang, Ximing Liu, Peng Tang, Songyuan Li, Xincheng Xiang\",\"doi\":\"10.3233/XST-240032\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Background: </strong>The polychromatic X-rays generated by a linear accelerator (Linac) often result in noticeable hardening artifacts in images, posing a significant challenge to accurate defect identification. To address this issue, a simple yet effective approach is to introduce filters at the radiation source outlet. However, current methods are often empirical, lacking scientifically sound metrics.</p><p><strong>Objective: </strong>This study introduces an innovative filter design method that optimizes filter performance by balancing the impact of ray intensity and energy on image quality.</p><p><strong>Materials and methods: </strong>Firstly, different spectra under various materials and thicknesses of filters were obtained using GEometry ANd Tracking (Geant4) simulation. Subsequently, these spectra and their corresponding incident photon counts were used as input sources to generate different reconstructed images. By comprehensively comparing the intensity differences and noise in images of defective and non-defective regions, along with considering hardening indicators, the optimal filter was determined.</p><p><strong>Results: </strong>The optimized filter was applied to a Linac-based X-ray computed tomography (CT) detection system designed for identifying defects in graphite materials within high-temperature gas-cooled reactor (HTR), with defect dimensions of 2 mm. After adding the filter, the hardening effect reduced by 22%, and the Defect Contrast Index (DCI) reached 3.226.</p><p><strong>Conclusion: </strong>The filter designed based on the parameters of Average Difference (AD) and Defect Contrast Index (DCI) can effectively improve the quality of defect images.</p>\",\"PeriodicalId\":49948,\"journal\":{\"name\":\"Journal of X-Ray Science and Technology\",\"volume\":\" \",\"pages\":\"1137-1150\"},\"PeriodicalIF\":1.7000,\"publicationDate\":\"2024-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of X-Ray Science and Technology\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.3233/XST-240032\",\"RegionNum\":3,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"INSTRUMENTS & INSTRUMENTATION\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of X-Ray Science and Technology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.3233/XST-240032","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"INSTRUMENTS & INSTRUMENTATION","Score":null,"Total":0}
引用次数: 0
摘要
背景:直线加速器(Linac)产生的多色 X 射线经常会在图像中产生明显的硬化伪影,给准确识别缺陷带来巨大挑战。为解决这一问题,一种简单而有效的方法是在辐射源出口处引入滤波器。然而,目前的方法往往是经验性的,缺乏科学合理的衡量标准:本研究介绍了一种创新的滤波器设计方法,通过平衡射线强度和能量对图像质量的影响来优化滤波器性能:首先,使用 GEometry ANd Tracking(Geant4)模拟获得了不同材料和厚度滤光片下的不同光谱。随后,将这些光谱及其相应的入射光子计数作为输入源,生成不同的重建图像。通过综合比较缺陷和非缺陷区域图像的强度差异和噪声,并考虑硬化指标,确定了最佳滤波器:将优化滤波器应用于基于直列加速器的 X 射线计算机断层扫描(CT)检测系统,该系统设计用于识别高温气冷堆(HTR)中石墨材料的缺陷,缺陷尺寸为 2 毫米。加入滤波器后,硬化效应降低了 22%,缺陷对比指数(DCI)达到 3.226.Conclusion:根据平均差(AD)和缺陷对比指数(DCI)参数设计的滤波器能有效提高缺陷图像的质量。
An optimized filter design approach for enhancing imaging quality in industrial linear accelerator.
Background: The polychromatic X-rays generated by a linear accelerator (Linac) often result in noticeable hardening artifacts in images, posing a significant challenge to accurate defect identification. To address this issue, a simple yet effective approach is to introduce filters at the radiation source outlet. However, current methods are often empirical, lacking scientifically sound metrics.
Objective: This study introduces an innovative filter design method that optimizes filter performance by balancing the impact of ray intensity and energy on image quality.
Materials and methods: Firstly, different spectra under various materials and thicknesses of filters were obtained using GEometry ANd Tracking (Geant4) simulation. Subsequently, these spectra and their corresponding incident photon counts were used as input sources to generate different reconstructed images. By comprehensively comparing the intensity differences and noise in images of defective and non-defective regions, along with considering hardening indicators, the optimal filter was determined.
Results: The optimized filter was applied to a Linac-based X-ray computed tomography (CT) detection system designed for identifying defects in graphite materials within high-temperature gas-cooled reactor (HTR), with defect dimensions of 2 mm. After adding the filter, the hardening effect reduced by 22%, and the Defect Contrast Index (DCI) reached 3.226.
Conclusion: The filter designed based on the parameters of Average Difference (AD) and Defect Contrast Index (DCI) can effectively improve the quality of defect images.
期刊介绍:
Research areas within the scope of the journal include:
Interaction of x-rays with matter: x-ray phenomena, biological effects of radiation, radiation safety and optical constants
X-ray sources: x-rays from synchrotrons, x-ray lasers, plasmas, and other sources, conventional or unconventional
Optical elements: grazing incidence optics, multilayer mirrors, zone plates, gratings, other diffraction optics
Optical instruments: interferometers, spectrometers, microscopes, telescopes, microprobes