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Ito H, Matsubara K, Kobayashi I, Sakai T, Isobe T, Yanagawa N, Ochi S. Usefulness of a lead-acrylic shield for reducing lens dose of assistant in x-ray CT examination. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:021529. [PMID: 35705067 DOI: 10.1088/1361-6498/ac7919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
In computed tomography (CT) examinations, the usefulness of protective glasses for reducing lens exposure to assistants has been reported. The present study aimed to compare the dose reduction effect for assistants with lead-acrylic shields and protective glasses (0.07 mm Pb, 0.5 mm Pb) during CT examination. The air dose distribution in a CT examination room with and without a lead-acrylic shield was compared. It was found that the amount of scattered radiation was significantly reduced by installing a lead-acrylic shield at the CT gantry aperture. Moreover, the reduction rate of air kerma at the assistant's lens was higher using the lead acrylic shield than with the protective glasses-95.7% during head holding and 76.1% during assisted ventilation.
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Kozuma K, Chikamori T, Hashimoto J, Honye J, Ikeda T, Ishiwata S, Kato M, Kondo H, Matsubara K, Matsumoto K, Matsumoto N, Motoyama S, Obunai K, Sakamoto H, Soejima K, Suzuki S, Abe K, Amano H, Hioki H, Iimori T, Kawai H, Kosuge H, Nakama T, Suzuki Y, Takeda K, Ueda A, Yamashita T, Hirao K, Kimura T, Nagai R, Nakamura M, Shimizu W, Tamaki N. JCS 2021 Guideline on Radiation Safety in Cardiology. Circ J 2022; 86:1148-1203. [DOI: 10.1253/circj.cj-21-0379] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Takei Y, Miyazaki O, Matsubara K, Suzuki S, Muramatsu Y, Fukunaga M, Akahane M. [Scientific Research Group Report: Nationwide Survey on Radiation Exposure of Pediatric CT Examination in Japan (2018)]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2022; 78:372-380. [PMID: 35236791 DOI: 10.6009/jjrt.2022-1181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
PURPOSE To understand the latest pediatric computed tomography (CT) exposure required for the revision of national DRLs. METHODS A questionnaire was sent to 409 facilities where the members of the Japanese Society of Radiological Technology and the Japanese Society of Pediatric Radiology are enrolled. We investigated the imaging conditions, CTDIvol, and DLP of the pediatric head, chest, and abdominal CT examinations. RESULTS In all, 43 facilities (11%) responded to our survey. multi detector-row CT (MDCT) systems were available in all surveyed facilities. More than 98% of the MDCT systems had more than 64 detector rows. The CTDIvol of all CT protocols was lower than the NDRL due to the progress of updating to MDCTs with radiation exposure reduction functions such as an iterative reconstruction, but the DLP of head and abdominal CT protocols of some age group were higher than NDRL. CONCLUSION It is necessary to review the imaging protocol with the attending physician and radiologist and consider further optimization of medical exposure.
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Tomioka Y, Sugimoto S, Kawana S, Kubo Y, Shimizu D, Matsubara K, Tanaka S, Miyoshi K, Okazaki M, Toyooka S. Identification of Single-Nucleotide Polymorphisms Associated with Renal Dysfunction After Lung Transplantation Using Ethnic-Specific SNP Array. J Heart Lung Transplant 2022. [DOI: 10.1016/j.healun.2022.01.623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Kubo Y, Sugimoto S, Shiotani T, Kawana S, Shimizu D, Matsubara K, Hashimoto K, Tanaka S, Shien K, Suzawa K, Miyoshi K, Yamamoto H, Okazaki M, Toyooka S. The Percentage of Low Attenuation Area on Computed Tomography to Detect Chronic Lung Allograft Dysfunction After Bilateral Lung Transplantation. J Heart Lung Transplant 2022. [DOI: 10.1016/j.healun.2022.01.247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Shimizu D, Okazaki M, Sugimoto S, Kinoshita R, Kawana S, Kubo Y, Matsubara K, Nakata K, Matsukawa A, Sakaguchi M, Toyooka S. Inhibiting S100A8/A9 Attenuates Airway Obstruction in a Mouse Heterotopic Tracheal Transplantation Model. J Heart Lung Transplant 2022. [DOI: 10.1016/j.healun.2022.01.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Chusin T, Yabsantia S, Matsubara K. The measurement of entrance surface dose using optically stimulated luminescence dosimeters for determining average glandular dose in digital breast tomosynthesis: Measurement and simulation study. J Appl Clin Med Phys 2022; 23:e13485. [PMID: 35041264 PMCID: PMC8803297 DOI: 10.1002/acm2.13485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/09/2021] [Accepted: 11/14/2021] [Indexed: 11/19/2022] Open
Abstract
This study aimed to evaluate the feasibility of using optically stimulated luminescence dosimeters (OSLDs), nanoDots, for the determination of an average glandular dose (AGD) with a specific digital breast tomosynthesis (DBT) system, whereas the X-ray tube was fixed (2D mode) and moved (3D mode). The entrance surface air kerma (ESAK) was measured by placing the nanoDots on the surface of a polymethyl methacrylate (PMMA) phantom with 25, 28, and 34 kV W/Rh techniques. The experimental setup of the ESAK measurement was simulated using a Monte Carlo simulation code to determine the ESAK and the backscatter factor (BSF). The AGD was calculated by dividing the ESAK values over the corresponding BSF factors for each PMMA phantom thickness and multiplying the AGD conversion factors. The AGD determination by the nanoDots variated within ±5% for both 2D and 3D modes, compared to those determined using an ionization chamber. The results were similarly observed for the simulation, except for the 25 kV on the 3D mode. Regarding the International Atomic Energy Agency technical reports series number 457, the nanoDots can be used for the AGD determination with realistic 2D and 3D image acquisitions based on ±10% uncertainty.
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Suzuki C, Nakano J, Matsubara K. [Effect of Automatic Extraction Accuracy by Different Image Reconstruction Methods Using a Three-dimensional Image Analysis System for Pulmonary Segmentectomy Preoperative CT Angiography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:1309-1316. [PMID: 34803111 DOI: 10.6009/jjrt.2021_jsrt_77.11.1309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study aimed to determine the optimal image reconstruction method for preoperative computed tomography (CT) angiography for pulmonary segmentectomy. This study enrolled 20 patients who underwent contrast-enhanced CT examination for pulmonary segmentectomy. The optimal image reconstruction algorithm among four different reconstruction algorithms (filtered back projection, hybrid iterative reconstruction, model- based iterative reconstruction, and deep learning reconstruction [DLR]) was investigated by assessing the CT numbers, vessel extraction ratios, and misclassification ratios. The vessel extraction ratios for main and subsegment branches reconstructed using DLR were significantly higher than those using other reconstruction algorithms (96.7% and 90.8% for pulmonary artery and vein, respectively). The misclassification ratios at the right upper lobe pulmonary vessels (V1 and V2) were especially high because they were close to the superior vena cava, and their CT numbers were similar in all four reconstructions. In conclusion, the DLR allows a high extraction rate of pulmonary blood vessels and a low misclassification rate of automatic extraction.
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Fukuda A, Lin PJP, Ichikawa N, Matsubara K. Determination of geometric information and radiation field overlaps on the skin in percutaneous coronary interventions with computer-aided design-based X-ray beam modeling. J Appl Clin Med Phys 2021; 22:140-148. [PMID: 34699677 PMCID: PMC8664137 DOI: 10.1002/acm2.13457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 09/18/2021] [Accepted: 10/05/2021] [Indexed: 11/12/2022] Open
Abstract
PURPOSE This study aimed to develop a method for the determination of the source-to-surface distance (SSD), the X-ray beam area in a plane perpendicular to the beam axis at the entrance skin surface (Ap ), and the X-ray beam area on the actual skin surface (As ) during percutaneous coronary intervention (PCI). MATERIALS AND METHODS Male and female anthropomorphic phantoms were scanned on a computed tomography scanner, and the data were transferred to a commercially available computer-aided design (CAD) software. A cardiovascular angiography system with a 200 × 200 mm flat-panel detector with a field-of-view of 175 × 175 mm was modeled with the CAD software. Both phantoms were independently placed on 40 mm thick pads, and the examination tabletop at the patient entrance reference point. Upon panning, the heart center was aligned to the central beam axis. The SSD, Ap , and As were determined with the measurement tool and Boolean intersection operations at 10 gantry angulations. RESULTS The means and standard deviations of the SSD, Ap , and As for the male and female phantoms were 573 ± 15 and 580 ± 15 mm, 8799 ± 1009 and 9661 ± 1152 mm2 , 10495 ± 602 and 11913 ± 600 mm2 , respectively. The number of As overlaps for the male and female phantoms were 15/45 and 21/45 view combinations, respectively. CONCLUSIONS CAD-based X-ray beam modeling is useful for the determination of the SSD, Ap , and As . Furthermore, the knowledge of the As distribution helps to reduce the As overlap in PCI.
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Noto K, Segawa K, Yoshikawa R, Moribe R, Kojima H, Matsubara K, Takemura A. [A Simple Measurement Method for Verifying the Accuracy of the Displayed Dose on an Over-couch-type X-ray Fluoroscopic System]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:1180-1185. [PMID: 34670925 DOI: 10.6009/jjrt.2021_jsrt_77.10.1180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The purpose of this study was to establish a simple measurement method to verify the accuracy of incident air kerma (Ka, r) and air kerma area product (PKA) displayed on an over-couch-type X-ray fluoroscopy system. A dosimeter was located at the patient entrance reference point, and the irradiation field size was set to 10×10 cm. A lead plate was placed on the couchtop to protect the image receptor, and the duration of fluoroscopy was set to 1 min. The Ka, r was measured with the proposed method and the Japanese Industrial Standards (JIS) method on three X-ray fluoroscopy units of different manufactures. The effect of backscattered X-rays from the lead plate was calculated using Monte Carlo methods. The errors of the displayed Ka, r and PKA to the measured Ka, r and PKA with our proposed method were calculated. There was no significant difference in the measured Ka, r between the proposed method and the JIS method in all units. The effect of backscattered X-ray was ≤0.5%. The errors of displayed Ka, r and PKA to those measured were in the range of 3.4 to 15.7% and -4.1 to 20.3%, respectively, which met the tolerance for accuracy of ±35% in accordance with the JIS method. We found that our proposed method was simple and that the accuracy of measured values was comparable to that of the JIS method.
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Ichikawa N, Fukuda A, Hayashi T, Matsubara K. Effect of equalization filters on measurements with kerma-area product meter in a cardiovascular angiography system. J Appl Clin Med Phys 2021; 22:177-185. [PMID: 34610646 PMCID: PMC8664145 DOI: 10.1002/acm2.13444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 11/22/2022] Open
Abstract
Purpose This study aimed to evaluate the effect of equalization filters (EFs) on the kerma‐area product (KAPQKM) and incident air‐kerma (Ka,i,QKM) using a kerma‐area product (KAP) meter. In addition, potential underestimations of the Ka,i,QKM values by EFs were identified. Materials and methods A portable flat‐panel detector (FPD) was placed to measure the X‐ray beam area (A) and EFs dimension at patient entrance reference point (PERP). Afterward, a 6‐cm3 external ionization chamber was placed to measure incident air‐kerma (Ka,i,Qext) at PERP instead of the portable FPD. KAP reading and Ka,i,Qext were simultaneously measured at several X‐ray beam qualities with and without EFs. The X‐ray beam quality correction factor by KAP meter (kQ,Q0KM) was calculated by A, Ka,i,Qext and KAP reading to acquire the KAPQKM and Ka,i,QKM. Upon completion of the measurements, KAPQKM, Ka,i,QKM, and Ka,i,Qext were plotted as functions of tube potential, spectral filter, and EFs dimension. Moreover, Ka,i,QKM/Ka,i,Qext values were calculated to evaluate the Ka,i,QKM underestimation. Results The kQ,Q0KM values increased with an increase in the X‐ray tube potential and spectral filter, and the maximum kQ,Q0KM was 1.18. KAPQKM and Ka,i,QKM decreased as functions of EFs dimension, whereas Ka,i,Qext was almost constant. Ka,i,QKM/Ka,i,Qext decreased with an increase in EFs dimension but increased with an increase in tube potential and spectral filter, and the range was 0.55–1.01. Conclusions Ka,i,QKM value was up to approximately two times lower than the Ka,i,Qext values by EFs. When using the Ka,i,QKM value, the potential Ka,i,QKM underestimation with EFs should be considered.
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Matsubara K, Takei Y, Mori H, Kobayashi I, Noto K, Igarashi T, Suzuki S, Akahane K. Corrigendum to "A multicenter study of radiation doses to the eye lenses of medical staff performing non-vascular imaging and interventional radiology procedures in Japan" [Physica Medica 74 (2020) 83-91]. Phys Med 2021; 88:262-263. [PMID: 34315002 DOI: 10.1016/j.ejmp.2021.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Furukawa Y, Matsubara K, Tsutsumi Y. A comparison of automatic and manual compensation methods for the calculation of tube currents during off-centered patient positioning with a noise-based automatic exposure control system in computed tomography. Phys Eng Sci Med 2021; 44:823-832. [PMID: 34297309 DOI: 10.1007/s13246-021-01033-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 07/12/2021] [Indexed: 11/30/2022]
Abstract
Automatic exposure control (AEC) is used to optimize the X-ray tube output during computed tomography (CT) scans. However, calculation of the tube current by AEC can be affected when a patient is not aligned with the rotational center of the X-ray tube. An automatic couch height-positioning compensation mechanism provides a corrective function when the patient is off-center. In this study, we aimed to (a) evaluate the performance characteristics of the positioning compensation mechanism and (b) confirm whether our proposed compensation method can be properly applied to a noise-based AEC system even if the CT device is not equipped with a positioning compensation mechanism. An elliptical phantom was scanned at various table heights on systems without/with the positioning compensation mechanism. Expressions describing the offset from the gantry's isocenter and adjusted standard deviation settings were derived and used in our proposed compensation method. A phantom was scanned at various table heights with our proposed compensation method, and volume CT dose index (CTDIvol) and image noise levels were obtained. An anthropomorphic chest phantom was also scanned using the proposed compensation method to verify its accuracy. When the positioning compensation mechanism was used, it yielded a constant CTDIvol and image noise levels at various table heights tested. A comparison between our proposed method and the positioning compensation mechanism for both the elliptical and chest phantoms yielded similar CTDIvol. Therefore, both automatic and manual positioning compensation methods are useful for avoiding AEC miscalculations in off-centered patient positioning cases.
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Ueno H, Matsubara K, Takemura A, Hizume M, Bou S. Evaluation of the relationship between phantom position and computed tomography dose index in cone beam computed tomography when assuming breast irradiation. J Appl Clin Med Phys 2021; 22:262-267. [PMID: 34048143 PMCID: PMC8200449 DOI: 10.1002/acm2.13282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/21/2021] [Accepted: 04/23/2021] [Indexed: 11/21/2022] Open
Abstract
This study aims to investigate the influence of the phantom position on weighted computed tomography dose index (CTDIw ) in cone beam computed tomography (CBCT) when assuming breast irradiation. Computed tomography dose index (CTDI) was measured by the x-ray volume imaging of CBCT using parameters for image-guided radiation therapy (IGRT) in right breast irradiation. The measurement points of CTDI ranged from 0 (center) to 16 cm in the right-left (RL) direction, and from 0 (center) to 7.5 cm in the anterior-posterior (AP) direction, which assumed right breast irradiation. A nonuniform change exists in the relative value of CTDIw when the phantom deviated from the isocenter of CBCT. The CTDIw was ~30% lower compared with the value at the isocenter of CBCT when the phantom deviated 7.5 and 16 cm at the AP and RL directions, respectively. This study confirmed the influence of the phantom position on the CTDI values of CBCT. The CTDI measured at the isocenter of CBCT overestimates that measured at the irradiation center of the breast.
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Nagai N, Shindo N, Wada A, Izu H, Fujii T, Matsubara K, Wada Y, Sakane N. Effects of Rice Wine Lees on Cognitive Function in Community-Dwelling Physically Active Older Adults: A Pilot Randomized Controlled Trial. JPAD-JOURNAL OF PREVENTION OF ALZHEIMERS DISEASE 2021; 7:95-103. [PMID: 32236398 DOI: 10.14283/jpad.2019.45] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Rice wine lees (RWL), a Japanese traditional fermented product, is a rich source of one-carbon metabolism-related nutrients, which may have beneficial effects on cognitive function. OBJECTIVES We aimed to examine the effect of the RWL on cognitive function in community-dwelling physically active older adults. DESIGN Double-blind, randomized, placebo-controlled study (clinical trial number: UMIN 000027158). SETTING Community-based intervention including assessments conducted at the University of Hyogo and a public liberal arts school in Himeji City, Japan. PARTICIPANTS A total of 35 community-dwelling older adults (68-80 years) who performed mild exercise before and during the trial were assigned to either the RWL (n=17) or the placebo group (n=18). INTERVENTION Daily consumption of 50 g RWL powder, which contained one-carbon metabolism-related nutrients, or the placebo powder (made from soy protein and dextrin) for 12 weeks. Both supplements included equivalent amounts of energy and protein. MEASUREMENTS Montreal Cognitive Assessment, computerized cognitive function test, and measurements of serum predictive biomarkers (transthyretin, apolipoprotein A1, and complement C3) were conducted at baseline and follow-up. RESULTS Visual selective attention and serum transthyretin significantly improved in the RWL group, whereas there was no significant change in the placebo group. No significant group difference was observed in the remaining cognitive performance tests. CONCLUSIONS RWL supplements seem to have a few effects on cognitive function in community-dwelling physically active older adults. However, the impact was limited; therefore, further studies with sufficient sample size are warranted to elucidate this issue.
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Matsubara K. [4. Phantoms for Dose Evaluation in Computed Tomography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:406-409. [PMID: 33883376 DOI: 10.6009/jjrt.2021_jsrt_77.4.406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Otani S, Tomioka Y, Matsubara K, Shimizu D, Yamamoto H, Shiotani T, Suzawa K, Miyoshi K, Yamamoto H, Okazaki M, Sugimoto S, Yamane M, Toyooka S. Pediatric Lung Transplantation−Intermediate Outcomes of a Japanese Center. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Matsubara K, Otani S, Shimizu D, Tomioka Y, Shiotani T, Yamamoto H, Miyoshi K, Okazaki M, Sugimoto S, Yamane M, Toyooka S. Risk Assessment of Chronic Lung Allograft Dysfunction Phenotypes after Living-Donor Lobar Lung Transplantation According to the 2019 ISHLT Classification System. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Yamamoto H, Sugimoto S, Suzuki E, Tomioka Y, Shiotani T, Shimizu D, Matsubara K, Miyoshi K, Otani S, Okazaki M, Yamane M, Toyooka S. Combination of Neutrophil to Lymphocyte Ratio and Glasgow Prognostic Score Improves Prognostic Accuracy in Lung Transplantation: Validation of 9 Preoperative Prognostic Scoring Methods. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.1007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Shiotani T, Sugimoto S, Yamamoto H, Matsubara K, Shimizu D, Nakata K, Tomioka Y, Miyoshi K, Otani S, Okazaki M, Yamane M, Toyooka S. Plasma Levels of Histidine-Rich Glycoprotein are Associated with the Development of Primary Graft Dysfunction after Lung Transplantation. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Tomioka Y, Sugimoto S, Matsubara K, Shimizu D, Yamamoto H, Shiotani T, Miyoshi K, Ohtani S, Okazaki M, Yamane M, Toyooka S. The UNCX Polymorphism is Associated with the Development of Renal Dysfunction after Lung Transplantation. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Sako K, Matsubara K, Matsumoto M. [An Evaluation of Radiation Dose for Wide Volume Scan during Chest CT]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:284-292. [PMID: 33746176 DOI: 10.6009/jjrt.2021_jsrt_77_3.284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE A volume scan can cover a range of 160 mm with a single gantry rotation. It can be performed sequentially (a wide volume [WV] scan) to cover more than 160 mm, and volume Xact+ (Xact+) can be used when volume scan is done to extend the reconstruction area. The purpose of this study was to investigate the dose distribution and organ doses for a WV scan during chest CT. METHOD We arranged radiophotoluminescence glass dosimeters (RPLDs) linearly on the surface and inside of the phantom to evaluate the dose distribution along the z-axis. We also placed RPLDs at the lens, thyroid, and breast positions to evaluate organ doses. We performed WV and helical scans and WV scan using Xact+. RESULT The absorbed doses increased at the borders of the volume scans, and dose peaks were observed there. The organ doses for the WV scan outside the acquisition range were lower than those for the helical scan. The organ doses inside the acquisition range changed by the locations of borders. CONCLUSION The WV scan increases the absorbed doses at the overlapping scanned regions, which can be reduced by using Xact+.
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Hanaoka K, Matsubara K, Takatsu Y. [Reports of JSRT's Symposium at AOCMP 2020]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:235-236. [PMID: 33612702 DOI: 10.6009/jjrt.2021_jsrt_77.2.235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Matsubara K, Yoshida S, Hirosawa A, Chusin T, Furukawa Y. Characterization of Small Dosimeters Used for Measurement of Eye Lens Dose for Medical Staff during Fluoroscopic Examination. Diagnostics (Basel) 2021; 11:diagnostics11020150. [PMID: 33498545 PMCID: PMC7909523 DOI: 10.3390/diagnostics11020150] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 12/02/2022] Open
Abstract
This study aimed to evaluate the property of small dosimeters used for measuring eye lens doses for medical staff during fluoroscopic examination. Dose linearity, energy dependence, and directional dependence of scattered X-rays were evaluated for small radiophotoluminescence glass dosimeters (RPLDs), those with a tin filter (Sn-RPLDs), and small optically stimulated luminescence dosimeters (OSLDs). These dosimeters were pasted on radioprotective glasses, and accumulated air kerma was obtained after irradiating the X-rays to a patient phantom. Strong correlations existed between fluoroscopic time and accumulated air kerma in all types of dosimeters. The energy dependence of Sn-RPLD and OSLD was smaller than that of RPLD. The relative dose value of the OSLD gradually decreased as the angle of the OSLD against the scattered X-rays was larger or lower than the right angle in the horizontal direction. The ranges of relative dose values of RPLD and Sn-RPLD were larger than that of OSLD in the vertical direction. The OSLDs showed lower doses than the RPLDs and Sn-RPLDs, especially on the right side of the radioprotective glasses. These results showed that RPLDs, Sn-RPLDs, and OSLDs had different dosimeter properties, and influence measured eye lens doses for the physician, especially on the opposite side of the patient.
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Tanaka T, Matsubara K, Kobayashi S. Evaluation of peak skin dose during percutaneous coronary intervention procedures: relationship with fluoroscopic pulse rate and target vessel. Radiol Phys Technol 2021; 14:34-40. [PMID: 33403510 DOI: 10.1007/s12194-020-00599-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 11/14/2020] [Accepted: 11/20/2020] [Indexed: 12/18/2022]
Abstract
This study aimed to evaluate the relationship between the peak skin dose (PSD) associated with radiation skin injury and the fluoroscopic pulse rate or target vessel during percutaneous coronary intervention (PCI) procedures. We consecutively included 213 patients who underwent PCI procedures. The fluoroscopic time (FT), total number of cine frames, reference air kerma (RAK), and PSD were compared between the two types of fluoroscopic pulse rates (10 and 7.5 pulses/s) and among target vessels. The total number of X-ray tube angulations for each target vessel was also investigated. The median FT was 21.5 min in the 10 pulses/s group and 19.4 min in the 7.5 pulses/s group (p = 0.068, Wilcoxon rank sum test). The median PSD in the 10 pulses/s group was 749 mGy, which was significantly higher than that in the 7.5 pulses/s group (549 mGy) (p < 0.001). The median RAK in the right coronary artery (RCA) was equivalent to that in the left anterior descending artery. However, among the target vessels, the median PSD tended to be the highest in the RCA. There was a difference in the X-ray tube angulation used depending on the target vessel. PCI in the RCA used the left anterior oblique angle more frequently than PCI in the other vessels and tended to use only one angulation. The calculated PSD was related to the target vessel of the PCI procedure, and it was also closely related to the X-ray tube angulation.
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