Nihon Hoshasen Gijutsu Gakkai zasshi最新文献_第4页

[5. Image Guidance and Setup Accuracy in Particle Therapy]. (5。粒子治疗中的图像引导和设置精度[j]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-0710

Kiyotaka Wada

引用次数: 0

[Impact of Matrix Size and Magnification Ratio on PET Imaging Using a Semiconductor PET/CT System]. [矩阵尺寸和放大倍率对半导体PET/CT成像系统的影响]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-1616

Shogo Fujita, Yukito Maeda, Masatoshi Morimoto, Yayoi Taniguchi, Yusuke Uehara, Akihiro Oishi, Keigo Omori, Keisuke Matsumoto, Keisuke Matsunami, Nobuyuki Kudomi, Takanobu Iwasaki

{"title":"[Impact of Matrix Size and Magnification Ratio on PET Imaging Using a Semiconductor PET/CT System].","authors":"Shogo Fujita, Yukito Maeda, Masatoshi Morimoto, Yayoi Taniguchi, Yusuke Uehara, Akihiro Oishi, Keigo Omori, Keisuke Matsumoto, Keisuke Matsunami, Nobuyuki Kudomi, Takanobu Iwasaki","doi":"10.6009/jjrt.26-1616","DOIUrl":"https://doi.org/10.6009/jjrt.26-1616","url":null,"abstract":"Purpose: We investigated the effects of matrix size and magnification ratio on positron emission tomography (PET) image quantitative characteristics using a semiconductor detector PET/CT.Methods: Three types of phantom were filled with 18F-fluorodeoxyglucose solution and scanned. Images were reconstructed using the ordered-subsets expectation-maximization method, with matrix sizes of 128, 220, 256, 440, 512, and 880, and magnification ratios of 1.0, 1.5, 2.0, 2.5, and 3.0. We evaluated the maximum standardized uptake value (SUVmax), percentage coefficient of variation (%CV), and full width at half maximum (FWHM).Results: Minimal differences in the SUVmax, %CV, and FWHM were observed between the matrix sizes of 128 and 220, and between 440, 512 and 880. However, significant differences were observed between the matrix sizes of 220 and 256, as the largest difference, and between 256 and 440. The influence of the magnification ratio on the image quality was small.Conclusion: The magnification ratio has a minor effect on quantitative values and image quality, whereas the impact of matrix size is significant. A noticeable difference in evaluation was observed between matrix sizes of 220 and 256. This was considered an important factor in determining the matrix size for this device.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148882288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[7. Quality Assurance and Quality Control in Particle Therapy]. (7。粒子治疗的质量保证与质量控制[j]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-0905

Yuto Matsuo

引用次数: 0

["Scrap and Build": A Period of Transformation for the Japanese Society of Radiological Technology]. [“废弃与建造”：日本放射技术学会的转型时期]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-0902

Hiroyuki Takei

引用次数: 0

[Domestic Market Trend for Medical Imaging and Radiological System]. 【医学影像与放射系统国内市场趋势】。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-0801

Osamu Uchiyama

引用次数: 0

[Impact of Hybrid Iterative Reconstruction Combined with a Sharpening Filter on Coronary Artery Stent Profile Characteristics and Visual Assessment in Coronary CT Angiography: A Phantom Study]. [混合迭代重建联合锐化滤波器对冠状动脉CT血管造影冠状动脉支架轮廓特征和视觉评估的影响：一项幻影研究]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-1696

Mizuki Kakisako, Ryo Watanabe, Makoto Fujiwara, Kenta Maruyama

{"title":"[Impact of Hybrid Iterative Reconstruction Combined with a Sharpening Filter on Coronary Artery Stent Profile Characteristics and Visual Assessment in Coronary CT Angiography: A Phantom Study].","authors":"Mizuki Kakisako, Ryo Watanabe, Makoto Fujiwara, Kenta Maruyama","doi":"10.6009/jjrt.26-1696","DOIUrl":"https://doi.org/10.6009/jjrt.26-1696","url":null,"abstract":"Purpose: In coronary CT angiography, we compared the profile characteristics and visual assessment of coronary stents between hybrid iterative reconstruction combined with a sharpening filter (S-HIR) and deep learning reconstruction (DLR).Methods: We scanned a performance evaluation phantom and a custom-made phantom incorporating a coronary artery stent with an inner diameter of 3.5 mm. Images were reconstructed using DLR, hybrid iterative reconstruction (HIR), and S-HIR of three sharpening strengths. We evaluated task-based transfer function (TTF) values, the maximum CT number of the stent struts, the error rate of the stent lumen diameter, rectangularity, and visual assessment performed by nine radiological technologists using Scheffé's paired comparison method.Results: In S-HIR, TTF values and rectangularity increased, while the error rate decreased with increasing sharpening strength. Visual assessment revealed no significant difference between sharpening medium filter+HIR (SM-HIR) and DLR. In contrast, sharpening high filter+HIR (SH-HIR) resulted in an excessive increase in the maximum CT number of the stent struts, and visual assessment scores decreased.Conclusion: The S-HIR method newly proposed in this study altered the profile characteristics of coronary artery stents and improved their visibility in coronary CT angiography under phantom conditions. In particular, SM-HIR showed no statistically significant difference from DLR in visual assessment and could serve as a useful technique for improving coronary stent visibility in CT systems without DLR.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[3. Radiographic Techniques Using Auxiliary Devices in General Radiography]. (3。在普通放射照相中使用辅助设备的放射照相技术]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-0409

Anna Isaka

引用次数: 0

[3. Data Literacy (1): Data Types, Central Values, and Variability]. (3。数据素养(1)：数据类型、中心值和可变性。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-0301

Asumi Yamazaki

引用次数: 0

[Preface]. (前言)。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-0309

Takahiro Kato, Yoshinori Tanabe

引用次数: 0

[Evaluating the Effect of Log-linear Interpolation on Half-value Layers Using Monte Carlo Simulation]. [用蒙特卡罗模拟评价对数线性插值对半值层的影响]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2026-01-01 DOI: 10.6009/jjrt.26-1526

Noriyo Yokotsuka, Hiroki Saito, Sho Maruyama

{"title":"[Evaluating the Effect of Log-linear Interpolation on Half-value Layers Using Monte Carlo Simulation].","authors":"Noriyo Yokotsuka, Hiroki Saito, Sho Maruyama","doi":"10.6009/jjrt.26-1526","DOIUrl":"10.6009/jjrt.26-1526","url":null,"abstract":"The half-value layer (HVL), an indicator of X-ray quality, is defined as the thickness of an aluminum (Al) filter that reduces the air kerma by half and is used to calculate the backscatter coefficient. HVL is determined from the attenuation curve of air kerma using log-linear interpolation. However, there are no references detailing the specific measurement method. This study aims to investigate the impact of varying the interval of Al filters used in the log-linear interpolation on the HVL, using Monte Carlo simulations. The Monte Carlo simulation was performed using Particle and Heavy Ion Transport code System (PHITS) Ver. 3.29. A photon point source was placed in the air, and the rectangular irradiation field was set to 5×5 cm at the detector position. The detector, simulated as a volume of 1 cm3 of air, was positioned 100 cm from the source. The Al filter thickness for the HVL was varied in increments of 0.1 mm. The HVL was calculated by linear interpolation, and the relative error was determined based on the minimum Al spacing. The X-ray tube voltages used were those of the RQR series (40, 50, 60, 70, 80, 90, 100, 120, and 150 kV). The beam qualities obtained from the measurements and the Monte Carlo simulation system were consistent with those specified for the RQR series in IEC 61267 within ±3.5%. The relative error of HVL for each tube voltage determined by simulation ranged from -0.5 to 4.6%, with a mean±standard deviation (median) of 1.12±0.95% (0.88%). The relative error was larger when the difference between the Al filter combinations was large and the interpolation coefficient α was 0.5. When the filter spacing is less than half the HVL, the accuracy of log-linear interpolation in HVL is less than ±1.5% relative error.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146121334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0