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

[Spatial Resolution and Uniformity of a Full-ring CZT SPECT/CT System: Comparison with a Conventional Anger-type SPECT/CT Instrument]. 全环形CZT SPECT/CT系统的空间分辨率和均匀性：与传统anger型SPECT/CT仪器的比较。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1527

Takashi Takeuchi, Yoshitaka Tanaka, Yasuhiro Kodama, Hayato Odagiri

{"title":"[Spatial Resolution and Uniformity of a Full-ring CZT SPECT/CT System: Comparison with a Conventional Anger-type SPECT/CT Instrument].","authors":"Takashi Takeuchi, Yoshitaka Tanaka, Yasuhiro Kodama, Hayato Odagiri","doi":"10.6009/jjrt.25-1527","DOIUrl":"https://doi.org/10.6009/jjrt.25-1527","url":null,"abstract":"Purpose: StarGuide (GE HealthCare, Haifa, Israel) is a full-ring SPECT/CT system based on Cadmium Zinc Telluride (CZT) technology. In this study, we aimed to compare the image quality of this CZT-based SPECT/CT to a conventional Anger-type SPECT/CT system (NM/CT 870 DR, 870DR; GE HealthCare).Methods: Tomographic sensitivity was calculated by recording the total number of counts detected during tomographic acquisition for a point source. We evaluated spatial resolution and image uniformity on each system using the full width half maximum (FWHM) of line sources and root mean square uniformity (%RMSU) of pool phantom, respectively. The voxel size of the StarGuide SPECT images was 2.46×2.46×2.46 mm3, compared to 4.42×4.42×4.42 mm3 on 870DR. These projection data were reconstructed using 3D-OSEM with a resolution recovery technique (RR). We compared 3 different algorithms: non-correction (NCRR), scatter correction (SCRR), and attenuation correction and scatter correction (ACSCRR).Results: Tomographic sensitivity of StarGuide and 870DR were estimated at 200.0 counts・s-1・MBq-1 and 193.3 counts・s-1・MBq-1, respectively. Spatial resolution at the center of the FOV was estimated at 2.6 mm for StarGuide and 5.4 mm for 870DR with ACSCRR. Likewise, the %RMSU was 21.7 for StarGuide and 24.6 for 870DR.Conclusion: The full-ring CZT SPECT/CT system has a superior spatial resolution and better image uniformity than the conventional Anger-type SPECT instrument, whereas tomographic sensitivity remains similar.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144044075","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

[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

[Deep Learning Approaches to Address the Shortage of Observers]. [解决观察者短缺的深度学习方法]。

Nihon Hoshasen Gijutsu Gakkai zasshi Pub Date : 2025-01-01 DOI: 10.6009/jjrt.25-1554

Nariaki Tabata, Tetsuya Ijichi, Masaya Tominaga, Kazunori Kitajima, Shuto Okaba, Lisa Sonoda, Shinichi Katou, Tomoya Masumoto, Asami Obata, Yuna Kawahara, Toshirou Inoue, Tadamitsu Ideguchi

{"title":"[Deep Learning Approaches to Address the Shortage of Observers].","authors":"Nariaki Tabata, Tetsuya Ijichi, Masaya Tominaga, Kazunori Kitajima, Shuto Okaba, Lisa Sonoda, Shinichi Katou, Tomoya Masumoto, Asami Obata, Yuna Kawahara, Toshirou Inoue, Tadamitsu Ideguchi","doi":"10.6009/jjrt.25-1554","DOIUrl":"https://doi.org/10.6009/jjrt.25-1554","url":null,"abstract":"Purpose: This study developed a deep learning-based artificial intelligence (AI) observer to address the shortage of skilled human observers and evaluated the impact of substituting human observers with AI.Methods: We used a CT system (Aquilion Prime SP; Canon Medical Systems, Tochigi) and modules CTP682 and CTP712 to scan the phantom (Catphan 700; Toyo Medic, Tokyo). The imaging conditions were set to a tube voltage of 120 kV and tube currents of 200, 160, 120, 80, 40, and 20 mA. Each condition was scanned twice, resulting in a total of 24 images. After the paired comparison experiment with 5 observers, deep learning models based on VGG19 and VGG16 were trained. We evaluated the variance, including both human and AI observers, and examined the impact of replacing humans with AI on the average degree of preference and statistical significance. These evaluations were conducted both when the training and assessments were from the same module and when they were from different modules.Results: Variance ranged from 0.085 to 0.177 (mean: 0.124). Despite using different modules for training and evaluation, the variance remained consistent, indicating that the results are independent of the training data. The average degree of preference and image rankings were nearly identical. Between 200 mA and 160 mA, AI results differed from human results in terms of statistical significance, though the difference was minimal. The discrepancy arose from differences in observations between humans and AI, yet it fell within the expected range of variation typically observed among human observers.Conclusion: Our results suggest that replacing human observers with AI has a minimal impact and may help alleviate observer shortages. The main limitation is the inability to modify evaluation criteria or stages with the trained models.","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"81 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144144744","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

[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

[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