Nihon Hoshasen Gijutsu Gakkai zasshi最新文献_第2页

[6. Radiation Protection in Medicine]. (6。医学上的辐射防护]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0402

Yasutaka Takei

引用次数: 0

[Investigation of the Influence of Image Reconstruction Parameters to Improve the Ability to Depict Internal Tumor Necrosis]. [研究图像重建参数对提高描绘内部肿瘤坏死能力的影响]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1453

Yuka Sakamoto, Yoshihiro Yamamoto, Tadaaki Uegaki

{"title":"[Investigation of the Influence of Image Reconstruction Parameters to Improve the Ability to Depict Internal Tumor Necrosis].","authors":"Yuka Sakamoto, Yoshihiro Yamamoto, Tadaaki Uegaki","doi":"10.6009/jjrt.25-1453","DOIUrl":"10.6009/jjrt.25-1453","url":null,"abstract":"Purpose: There are attempts to assess tumor heterogeneity by texture analysis. However, the ordered subsets-expectation maximization (OSEM) reconstruction method has problems depicting heterogeneities. The aim of this study was to identify image reconstruction parameters that improve the ability to depict internal tumor necrosis using a self-made phantom that simulates internal necrosis.Methods: Self-made phantoms were prepared using polypropylene cylinders with inner diameters of 18.0 mm and 6.0 mm. The concentration ratios of the simulated tumor : tumor interior were 4 : 0 and 4 : 1. For each reconstruction method, the iteration for OSEM and OSEM+point spread function (PSF) were 1 to 25 and the subset was 12. The β values for block sequential regularized expectation maximization (BSREM) were set between 10 and 400. We evaluated the features of the profile curve, contrast-to-noise ratio, and grey-level co-occurrence matrix (GLCM).Results: In the phantom study, OSEM and OSEM+PSF showed a better delineation of the differences between the inside and outside of the cylinder as iteration was increased and BSREM showed a better delineation as β was decreased. The highest value for each feature, both 4 : 0 and 4 : 1, was BSREM β 10 for angular second moment (ASM) and inverse differential moment (IDM), OSEM iteration 25 for contrast and entropy.Conclusion: We have identified image reconstruction parameters that improve the ability to visualize internal tumor necrosis. The parameter was BRSEM β 10.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049176","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

[Measurement for Maximum Leaf Velocity Using Piecewise Linear Approximation under Constant Acceleration of Multileaf Collimator]. [多叶准直器恒加速度下分段线性逼近的最大叶片速度测量]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1454

Masato Fujisawa, Takahide Hayakawa, Masaki Ohkubo, Ryuta Sasamoto

{"title":"[Measurement for Maximum Leaf Velocity Using Piecewise Linear Approximation under Constant Acceleration of Multileaf Collimator].","authors":"Masato Fujisawa, Takahide Hayakawa, Masaki Ohkubo, Ryuta Sasamoto","doi":"10.6009/jjrt.25-1454","DOIUrl":"10.6009/jjrt.25-1454","url":null,"abstract":"Purpose: The purpose of this study was to propose a method for measuring the maximum leaf velocity (Vmax) of the multileaf collimator (MLC) in a dynamic MLC irradiation.Methods: The irradiation was carried out with a plan in which the MLC leaves were constantly and gradually accelerated. Based on this plan, it was assumed that the velocity of each leaf v(t) (t is the elapsed time) would initially increase but plateau once it reached its maximum velocity. In the proposed method, v(t) was calculated from the log file data during irradiation, and fitted by a piecewise linear function consisting of 2 linear segments (constant acceleration and constant velocity segments); Vmax was determined as the velocity in the constant velocity segments. The Vmax values in each accelerator were obtained periodically for 7 months (20 measurements in total).Results: In all measurements, the constant acceleration and constant velocity segments in v(t) were clearly distinguished by the piecewise linear approximation, and the Vmax was determined. The mean Vmax value of each leaf ranged from 3.63 to 4.32 cm/s with standard deviations (SD) less than 0.04 cm/s.Conclusion: The proposed method made it possible to confirm the long-term stability of the Vmax easily.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143702356","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

[Celebrating the 80th Anniversary of the Japanese Journal of Radiological Technology: A Reflection on the Future of the JSRT]. [庆祝日本放射技术杂志80周年：对JSRT未来的思考]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0100

Takayuki Ishida, Koichi Chida, Yoshiyuki Hosokai, Katsuhiko Ogasawara, Shigeyoshi Saito, Atsushi Teramoto, Yasuo Takatsu

引用次数: 0

[Report on JIRA Environmental Seminar 2024]. [JIRA环境研讨会2024报告]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0105

Noriko Shimazu

引用次数: 0

[Report of FY2024 Study Meeting for Medical Imaging Industry]. 【2024财年医学影像产业研究会议报告】。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0309

Takeshi Funahashi

引用次数: 0

[Analysis of Factors That Promote Awareness of Breast MRI Surveillance for Carriers of Hereditary Breast Cancer Risk Genes ( BRCA1/2)]. [提高遗传性乳腺癌风险基因（BRCA1/2）携带者对乳腺磁共振成像监测认识的因素分析]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1495

Ikumi Kataoka, Mitsuyo Itoh, Mari Itoh, Tokiko Nakamura, Chieko Itaki, Tomisato Miura

{"title":"[Analysis of Factors That Promote Awareness of Breast MRI Surveillance for Carriers of Hereditary Breast Cancer Risk Genes ( BRCA1/2)].","authors":"Ikumi Kataoka, Mitsuyo Itoh, Mari Itoh, Tokiko Nakamura, Chieko Itaki, Tomisato Miura","doi":"10.6009/jjrt.25-1495","DOIUrl":"10.6009/jjrt.25-1495","url":null,"abstract":"Purpose: Hereditary breast and ovarian cancers (HBOC) carry a high risk of breast cancer, and detailed screening with contrast-enhanced breast MRI (breast MRI surveillance) is recommended. With the increase in the number of individuals diagnosed with HBOC, the demand for breast MRI surveillance is also rising. However, the current system is inadequate, with factors such as lack of knowledge and indifference among healthcare professionals, and insufficient understanding of breast MRI surveillance being cited. This study aims to investigate the knowledge of HBOC and the awareness of breast MRI surveillance among radiological technologists, and to analyze the factors that promote these practices.Methods: A web-based survey was conducted among radiological technologists at 1278 facilities with MRI installations.Results: Responses were obtained from 433 individuals. The knowledge of HBOC was insufficient, with 49.6% unaware that breast MRI surveillance is recommended. Factors promoting awareness included the amount of knowledge about HBOC, age, and the presence of MRI specialists and mammography screening specialists.Conclusion: By enhancing the acquisition of knowledge about HBOC and raising awareness of breast MRI surveillance, it is expected that discussions towards building a robust system will deepen.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049177","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. Clinical Operations in a 0.35T MR-Linac]. (7。0.35T MR-Linac的临床手术[j]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0405

Tatsuya Sakasai

引用次数: 0

[5. Clinical Operation of Ring-type Radiation Therapy System Equipped with Artificial Intelligence]. (5。人工智能环型放射治疗系统的临床操作[j]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-0101

Masahiko Toyota

引用次数: 0

[Evaluation of Reproducibility in Left Breast Deep Inspiration Breath-hold Irradiation Using Quantitative Assessment Software]. 用定量评估软件评价左乳深吸气屏气照射的再现性

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1470

Tomoki Harukuni, Kenji Matsumoto, Kengo Kosaka, Taishi Matsuda

引用次数: 0