Determination of appropriate energy threshold range for accurate estimation of effective atomic number considering statistical uncertainty in photon-counting techniques.
{"title":"Determination of appropriate energy threshold range for accurate estimation of effective atomic number considering statistical uncertainty in photon-counting techniques.","authors":"Tomonobu Haba, Hiroaki Hayashi, Tsukasa Takahashi, Shota Naito, Yuichi Furukawa, Shuichiro Yamamoto, Natsumi Kimoto, Shigeki Kobayashi","doi":"10.1002/acm2.70007","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>The energy threshold is an important parameter for precise material identification employing photon-counting techniques. However, in such applications, the appropriate energy threshold has not been clarified. Therefore, we aimed to determine the appropriate energy threshold range for precise material identification, focusing on effective atomic number (Z) values as an index.</p><p><strong>Methods: </strong>The atomic number was estimated using a previously proposed algorithm and Monte Carlo simulations. This algorithm included three steps: calculating the attenuation factor from the incident photon counts on a photon-counting detector, correcting the beam-hardening effects, and estimating the atomic number from the attenuation factor index using the calibration curve. Monte Carlo simulations were performed to add Poisson noise to an ideal x-ray spectrum. The total number of incident x-rays was set in the range of 10<sup>3</sup>-10<sup>6</sup>. The x-ray spectra were generated at tube voltages of 50-120 kV. Polymethyl methacrylate (Z = 6.5) and aluminum (Z = 13) were used for the analysis. The energy threshold was varied at intervals of 1 keV to estimate the atomic number. We evaluated the appropriate energy threshold range for accurately estimating the atomic number using the obtained atomic number data and statistical uncertainty under various conditions.</p><p><strong>Results: </strong>The appropriate energy threshold range was found to be 31-38 keV for a tube voltage range of 50-120 kV. At this energy threshold, the atomic number can be estimated within an accuracy of ± 0.7 at 10<sup>5</sup> counts for the atomic number range of 6.5 (PMMA) to 13 (Al).</p><p><strong>Conclusions: </strong>We found the appropriate energy threshold range. The findings of this study are expected to be useful for appropriately setting the energy threshold during precise material identification using photon-counting detectors for clinical applications.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e70007"},"PeriodicalIF":2.0000,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Clinical Medical Physics","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1002/acm2.70007","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: The energy threshold is an important parameter for precise material identification employing photon-counting techniques. However, in such applications, the appropriate energy threshold has not been clarified. Therefore, we aimed to determine the appropriate energy threshold range for precise material identification, focusing on effective atomic number (Z) values as an index.
Methods: The atomic number was estimated using a previously proposed algorithm and Monte Carlo simulations. This algorithm included three steps: calculating the attenuation factor from the incident photon counts on a photon-counting detector, correcting the beam-hardening effects, and estimating the atomic number from the attenuation factor index using the calibration curve. Monte Carlo simulations were performed to add Poisson noise to an ideal x-ray spectrum. The total number of incident x-rays was set in the range of 103-106. The x-ray spectra were generated at tube voltages of 50-120 kV. Polymethyl methacrylate (Z = 6.5) and aluminum (Z = 13) were used for the analysis. The energy threshold was varied at intervals of 1 keV to estimate the atomic number. We evaluated the appropriate energy threshold range for accurately estimating the atomic number using the obtained atomic number data and statistical uncertainty under various conditions.
Results: The appropriate energy threshold range was found to be 31-38 keV for a tube voltage range of 50-120 kV. At this energy threshold, the atomic number can be estimated within an accuracy of ± 0.7 at 105 counts for the atomic number range of 6.5 (PMMA) to 13 (Al).
Conclusions: We found the appropriate energy threshold range. The findings of this study are expected to be useful for appropriately setting the energy threshold during precise material identification using photon-counting detectors for clinical applications.
期刊介绍：
Journal of Applied Clinical Medical Physics is an international Open Access publication dedicated to clinical medical physics. JACMP welcomes original contributions dealing with all aspects of medical physics from scientists working in the clinical medical physics around the world. JACMP accepts only online submission.
JACMP will publish:
-Original Contributions: Peer-reviewed, investigations that represent new and significant contributions to the field. Recommended word count: up to 7500.
-Review Articles: Reviews of major areas or sub-areas in the field of clinical medical physics. These articles may be of any length and are peer reviewed.
-Technical Notes: These should be no longer than 3000 words, including key references.
-Letters to the Editor: Comments on papers published in JACMP or on any other matters of interest to clinical medical physics. These should not be more than 1250 (including the literature) and their publication is only based on the decision of the editor, who occasionally asks experts on the merit of the contents.
-Book Reviews: The editorial office solicits Book Reviews.
-Announcements of Forthcoming Meetings: The Editor may provide notice of forthcoming meetings, course offerings, and other events relevant to clinical medical physics.
-Parallel Opposed Editorial: We welcome topics relevant to clinical practice and medical physics profession. The contents can be controversial debate or opposed aspects of an issue. One author argues for the position and the other against. Each side of the debate contains an opening statement up to 800 words, followed by a rebuttal up to 500 words. Readers interested in participating in this series should contact the moderator with a proposed title and a short description of the topic
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
