Nihon Hoshasen Gijutsu Gakkai zasshi最新文献

{"title":"[Towards Further Advances and Internationalization of Radiological Physics and Technology].","authors":"Toshioh Fujibuchi","doi":"10.6009/jjrt.26-0405","DOIUrl":"https://doi.org/10.6009/jjrt.26-0405","url":null,"abstract":"","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147724961","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}

{"title":"[Effect of Implementing a General Imaging Management System on Promoting Medical Safety].","authors":"Ryo Ito, Airi Tatsui, Syota Fujii, Emiko Yamamoto, Kenichiro Okumura, Takashi Iimori","doi":"10.6009/jjrt.26-1609","DOIUrl":"10.6009/jjrt.26-1609","url":null,"abstract":"<p><strong>Purpose: </strong>Reducing unnecessary retakes is a critical responsibility of radiologic technologists and plays an important role in promoting medical safety by minimizing patient radiation exposure. This study aimed to evaluate the impact of retake visualization using the general radiography management system \"RADInsight\" and the effectiveness of the educational interventions through periodic retake review meetings.</p><p><strong>Methods: </strong>General radiographic examinations performed at our institution from June 2023 to October 2024 were retrospectively analyzed. Retake rates and contributing factors were examined by anatomical region and cause.</p><p><strong>Results: </strong>The overall retake rate significantly decreased from a maximum of 7.5% to 2.1%. Positioning errors were the most frequent cause of retakes, with notable improvements observed in lateral views of the knee and elbow following educational intervention. Inexperienced technologists showed a higher incidence of retakes due to motion artifacts and insufficient exposure.</p><p><strong>Conclusion: </strong>The combined use of RADInsight for retake monitoring and targeted educational intervention effectively reduced retake rates. This approach demonstrated its value as a practical strategy to support radiologic technologist training and reduce patient radiation exposure, thereby contributing to enhanced medical safety. Wider adoption and multi-institutional application are anticipated in the future.</p>","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147596669","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}

{"title":"[Fundamental Study on Fluoroscopy Dose Rate Reduction in Pediatric Angiography Using an X-ray Cut Filter].","authors":"Yusuke Takada, Hidemitsu Otsu, Naoki Yoshikawa, Kojiro Nishijima","doi":"10.6009/jjrt.26-1617","DOIUrl":"10.6009/jjrt.26-1617","url":null,"abstract":"<p><strong>Purpose: </strong>We evaluated the ability of an MJP X-ray cut filter (hereafter referred to as \"cut filter\") to reduce fluoroscopic dose rate and assessed its impact on image quality in pediatric angiography.</p><p><strong>Methods: </strong>Fundamental assessments included fluoroscopic dose rate measurements, spectral analysis, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and visual evaluation were conducted. Body thickness was also measured in 412 pediatric patients aged 10 years or younger. Image visibility was visually assessed using a paired-comparison method.</p><p><strong>Results: </strong>The use of a cut filter reduced the fluoroscopic dose rate by 15%-25%. Spectral analysis confirmed that the low-energy component was effectively reduced via use of a cut filter. Changes in SNR ranged from -1.7% to +3.0%. CNR decreased by 27% when polymethyl methacrylate (PMMA) thickness was 20 cm. Visual assessment showed an average degree of preference of 0.119 at a PMMA thickness of 20 cm. Respective average body thicknesses at 0 and 10 years of age were 10.5±0.63 and 17.0±2.04 cm, respectively.</p><p><strong>Conclusion: </strong>An MJP X-ray cut filter can reduce fluoroscopic dose rate while maintaining sufficient image visibility in pediatric angiography, particularly for patients with a body thickness of 15 cm or less.</p>","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148159370","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}

{"title":"[Usefulness of the Nasion-fourth Ventricle Line and the Tuberculum Sellae-internal Occipital Protuberance Line as Alternatives to the AC-PC Line in ¹²³I-ioflupane SPECT].","authors":"Kazuya Kobayashi, Anna Kinoshita, Syun Sasaki","doi":"10.6009/jjrt.26-1655","DOIUrl":"10.6009/jjrt.26-1655","url":null,"abstract":"<p><strong>Purpose: </strong>In ¹²³I-ioflupane single-photon emission computerized tomography, anatomical landmarks are often indistinct, making identification of the anterior commissure-posterior commissure (AC-PC) line difficult in clinical practice. This study evaluated the usefulness of the tuberculum sellae-occipital protuberance (TS-OP) line and the nasion-fourth ventricle (nasion-4V) line, which is routinely used at our institution, as alternative reference lines.</p><p><strong>Methods: </strong>Angular differences from the AC-PC line were calculated, and inter-observer reproducibility and agreement of each line were assessed using the ICC and Bland-Altman analysis. In addition, ΔSBR (specific binding ratio) was calculated using our institutional reference axis to investigate the effect of angular differences on quantitative values.</p><p><strong>Results: </strong>The largest angular difference from the AC-PC line was observed for the nasion-4V line (-2.5°), although no significant differences were found among the lines. All lines demonstrated good reproducibility; however, the TS-EOP line showed slightly lower agreement, likely due to differences in recognition of bony morphology. Bland-Altman analysis revealed that the nasion-4V line had the smallest bias, and the TS-IOP line also showed a small bias of less than 1°. Although the nasion-4V line exhibited a relatively larger angular difference, it maintained high reproducibility and agreement. An angular difference of approximately 2.5° resulted in a maximum SBR change of 0.15.</p><p><strong>Conclusion: </strong>The nasion-4V line demonstrated high reproducibility and agreement, while the TS-IOP line showed minimal deviation and can be defined using bony landmarks. Both may be considered alternative reference lines when the AC-PC line is difficult to identify, with the TS-IOP line potentially representing a more stable option.</p>","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148159368","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}

{"title":"[7. Data Analysis Methods (1): Cross Tabulation, Association Analysis].","authors":"Chisako Muramatsu","doi":"10.6009/jjrt.26-0709","DOIUrl":"https://doi.org/10.6009/jjrt.26-0709","url":null,"abstract":"","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148537831","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}

{"title":"[A Bayesian Approach to ADC-to-Dose Conversion in Radiochromic Film Dosimetry].","authors":"Yuki Tanimoto, Kohei Sugimoto, Masahide Tamori, Miho Yatsuki, Shohei Yoshida, Kazuma Sugahara, Masataka Oita","doi":"10.6009/jjrt.26-1707","DOIUrl":"https://doi.org/10.6009/jjrt.26-1707","url":null,"abstract":"<p><strong>Purpose: </strong>Radiochromic film is widely used for patient-specific intensity-modulated radiation therapy quality assurance (IMRT QA) because of its high spatial resolution. However, calibration for converting pixel values to dose requires irradiation at multiple known dose levels, resulting in a substantial workload. Consequently, in some institutions, calibration is performed only under limited circumstances, such as when the film lot changes. This study aimed to develop and validate a Bayesian inference model that estimates the calibration curve using previously acquired calibration datasets together with the unirradiated pixel value of the target film, thereby improving the efficiency of the calibration process.</p><p><strong>Methods: </strong>A total of 93 calibration datasets acquired using TomoHD were analyzed. A quadratic polynomial regression model was constructed with dose and elapsed time from irradiation to scanning as explanatory variables. Separate models were developed for each scanner orientation (portrait and landscape), and the intercept was estimated using the unirradiated pixel value of the target film. Bayesian inference was performed using Stan, and model convergence was evaluated by trace plots and the Rhat statistic. Model performance was validated using 10 EBT4 films from a different lot by comparing predicted and measured pixel values and evaluating dose errors.</p><p><strong>Results: </strong>All models showed good convergence, with Rhat values below 1.01. For the validation films, the pixel value error was less than 3.6%, and the coefficient of determination (R²) exceeded 0.99. The mean dose error was 2.7±1.3 cGy at 24.0 cGy and 37.5±12.8 cGy at 868.2 cGy. The maximum dose error was 66.6 cGy at 710.6 cGy.</p><p><strong>Conclusion: </strong>The proposed method demonstrated the feasibility of estimating the calibration curve using previously acquired calibration datasets and the unirradiated pixel value of the target film. This approach has the potential to improve the efficiency of radiochromic film calibration. Future studies should apply this method to patient-specific IMRT QA and investigate its impact on dose distribution evaluation.</p>","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148802731","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}

{"title":"[Recent Trends in Medical Device Regulations-Overview of the Amendments to the Pharmaceuticals and Medical Devices Act Promulgated in 2025 and Effective on May 1, 2026].","authors":"Hiroki Degawa","doi":"10.6009/jjrt.26-0908","DOIUrl":"https://doi.org/10.6009/jjrt.26-0908","url":null,"abstract":"","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":"149032192","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}

{"title":"[Composition of Patient Radiation Dose in Woven EndoBridge Embolization: Comparison with Stent-assisted Coiling].","authors":"Daiki Horita, Takayuki Nomura, Hiroaki Neki, Satoshi Goshima","doi":"10.6009/jjrt.26-1687","DOIUrl":"https://doi.org/10.6009/jjrt.26-1687","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this study was to clarify the composition of patient radiation dose in Woven EndoBridge embolization (WEB) and to compare it with stent-assisted coiling (SAC).</p><p><strong>Methods: </strong>Fifteen patients in the WEB group and 15 patients in the SAC group were retrospectively analyzed. Total air kerma at the reference point (K_a,r), fluoroscopy air kerma (Fl-K_a,r), stationary air kerma (St-K_a,r), rotational air kerma (Ro-K_a,r), air kerma-area product (P_KA), fluoroscopy time, number of acquisitions, procedure time, and peak skin dose (PSD) were compared between the two groups.</p><p><strong>Results: </strong>Fl-K_a,r, fluoroscopy time, procedure time, and PSD were significantly lower in the WEB group than in the SAC group. In contrast, Ro-K_a,r was higher in the WEB group. The proportion of Ro-K_a,r to K_a,r was 46% in the WEB group and 26% in the SAC group.</p><p><strong>Conclusion: </strong>Compared with SAC, WEB was associated with lower Fl-K_a,r and shorter procedure time, whereas the contribution of Ro-K_a,r was greater. Therefore, radiation dose management in WEB should not rely solely on K_a,r; rather, it is important to understand each dose component individually.</p>","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":"149186644","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}

{"title":"[8. Concept of Positioning and Radiographic Techniques Based on Relaxed Patient Position].","authors":"Shinichiro Hirose","doi":"10.6009/jjrt.26-1001","DOIUrl":"https://doi.org/10.6009/jjrt.26-1001","url":null,"abstract":"","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149240639","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}

{"title":"[Health Sciences, Tanabe Laboratory, Graduate School of Health Sciences, Okayama University].","authors":"Yoshinori Tanabe","doi":"10.6009/jjrt.26-0210","DOIUrl":"https://doi.org/10.6009/jjrt.26-0210","url":null,"abstract":"","PeriodicalId":74309,"journal":{"name":"Nihon Hoshasen Gijutsu Gakkai zasshi","volume":"82 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147277649","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}