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Kawabata T, Kamiyama S, Onodera S. [Usefulness of Copper Filter Addition and Potential for Dose Reduction in Hip-joint Radiography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2024:2024-1445. [PMID: 39245581 DOI: 10.6009/jjrt.2024-1445] [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: 09/10/2024]
Abstract
PURPOSE In this study, we evaluated image quality and radiation dose reduction when a Copper (Cu) filter was added to hip joint X-ray imaging. METHODS We measured effective energy without (0 mm) and with (0.1/0.2 mm) Cu-added filter at 70 kV, and we calculated soft tissue-bone contrast and signal-difference-to-noise-ratio (SDNR) under constant entrance surface dose. After that, we estimated the dose reduction rate. RESULTS The effective energy was 32.07 keV for 0 mm Cu, 37.59 keV for 0.1 mm Cu, and 40.91 keV for 0.2 mm Cu. As the thickness of the Cu-added filter was increased, contrast decreased, but SDNR increased. The dose reduction rate in bone calculated measuring SDNR was 34% for 0.1 mm Cu and 47% for 0.2 mm Cu in max. CONCLUSION It was suggested that adding Cu filter to hip-joint X-ray imaging could reduce entrance surface dose while maintaining the image quality based on SDNR.
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Affiliation(s)
- Tomoyoshi Kawabata
- Department of Radiology, Division of Medical Technology, Tohoku University Hospital
| | - Shoko Kamiyama
- Department of Radiology, Division of Medical Technology, Tohoku University Hospital
| | - Shu Onodera
- Department of Radiology, Division of Medical Technology, Tohoku University Hospital
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Nozoe S, Terazaki K, Sasaki M, Nakata M. Efficacy of gonadal shielding in dose reduction for female pelvic radiography. RADIATION PROTECTION DOSIMETRY 2024; 200:770-778. [PMID: 38726990 DOI: 10.1093/rpd/ncae116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/13/2024] [Accepted: 04/23/2024] [Indexed: 06/05/2024]
Abstract
This study aimed to evaluate the dose reduction using gonad shielding (GS) during pelvic imaging. Three types of pelvic images (radiography, magnetic resonance and computed tomography) were fused to elucidate the three-dimensional relationship between the position of ovaries and GS. To estimate the dose received by the ovaries, the off-axis dose at any given depth was measured under two different imaging conditions using thermoluminescence dosemeters and a polymethyl methacrylate phantom. The mean ovarian depth was 8.4 cm. The mean estimated ovarian dose without an additional filter was 0.36 mGy without GS and 0.14 mGy with GS. The mean estimated ovarian dose with an additional filter was 0.24 mGy without GS and 0.10 mGy with GS. The efficacy of ovarian dose reduction should be evaluated based on the achieved ovarian dose, considering the ovarian depth and use of additional filtration, rather than the ovarian protection rate of GS.
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Affiliation(s)
- Saki Nozoe
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
| | - Kei Terazaki
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
| | - Makoto Sasaki
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
| | - Manabu Nakata
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan
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Petit AL, Alwan R, Behr J, Calame P, Lenoir M, Ducou le Pointe H, Delabrousse É. Dose optimization in newborn abdominal radiography: Assessing the added value of additional filtration on radiation dose and image quality using an anthropomorphic phantom. RESEARCH IN DIAGNOSTIC AND INTERVENTIONAL IMAGING 2024; 10:100045. [PMID: 39077732 PMCID: PMC11265153 DOI: 10.1016/j.redii.2024.100045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 04/01/2024] [Indexed: 07/31/2024]
Abstract
Background Abdominal radiographs remain useful in newborns. Given the high radiation sensitivity of this population, it is necessary to optimize acquisition techniques to minimize radiation exposure. Objective Evaluate the effects of three additional filtrations on radiation dose and image quality in abdominal X-rays of newborns using an anthropomorphic phantom. Material and method Abdominal radiographs of an anthropomorphic newborn phantom were performed using acquisition parameters ranging from 55 to 70 kV and from 0.4 to 2.5 mAs, without and with three different additional filtrations: 0.1 mm copper (Cu) + 1 mm aluminum (Al), 0.2 mm copper + 1 mm aluminum, and 2 mm aluminum. For each X-ray the dose area product (DAP) was measured, the signal-to-noise ratio (SNR) was calculated, and image quality (IQ) was evaluated by two blinded radiologists using the absolute visual grading analysis (VGA) method. Results Adding an additional filtration resulted in a significant reduction in DAP, with a decrease of 42% using 2 mm Al filtration, 65% with 0.1 mm Cu + 1 mm Al filtration, and 78% with 0.2 mm Cu + 1 mm Al filtration (p < 0.01). The addition of 2 mm aluminum filtration does not significantly decrease the SNR (p = 0.31), CNR (p = 0.52) or the IQ (p = 0.12 and 0.401 for reader 1 and 2, respectively). However, adding copper-containing filtration leads to a significant decrease in, SNR, CNR and IQ. Conclusion Adding a 2 mm Al additional filtration for abdominal radiographs in newborns can significantly reduce the radiation dose without causing a significant decrease in image quality.
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Affiliation(s)
| | - Rabih Alwan
- Department of Radiology, hôpital Jean-Minjoz, Besançon, France
| | - Julien Behr
- Department of Radiology, hôpital Jean-Minjoz, Besançon, France
| | - Paul Calame
- Department of Radiology, hôpital Jean-Minjoz, Besançon, France
| | - Marion Lenoir
- Department of Radiology, hôpital Jean-Minjoz, Besançon, France
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Alzyoud K, Al-Murshedi S, England A. Effective dose and image quality for different patient sizes during AP upper abdominal radiography: A phantom study. Appl Radiat Isot 2023; 202:111060. [PMID: 37806283 DOI: 10.1016/j.apradiso.2023.111060] [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] [Received: 05/14/2023] [Revised: 09/17/2023] [Accepted: 09/28/2023] [Indexed: 10/10/2023]
Abstract
INTRODUCTION Undertaking medical imaging examinations on obese patients can present practical challenges. Choosing optimal imaging protocols can be difficult, especially when promoting the ALARA principle. The aim of this study was to assess the effects of increasing body part thickness on image quality (IQ) and effective dose (ED) during upper abdominal radiography. A secondary aim was to determine the optimum exposure settings for larger sized patients. METHODS Underweight, standard, overweight and obese abdomen sizes were simulated using an anthropomorphic upper abdomen phantom, without and with additional fat layers (6, 10 and 16 cm). Phantoms were imaged using a variety of tube potentials (70-110 kVp), automatic exposure control (AEC) and a source-to-image distance of 120 cm. IQ was assessed visually using a relative visual grading analysis (VGA) method. Radiation dose was evaluated by calculating the ED using the Monte Carlo PCXMC 2.0 computer program. RESULTS IQ values showed a statistical reduction (p = 0.006) with increasing phantom size across all examined tube potentials. The highest IQ scores (3.3, 2.8, 2.5 and 2.2, respectively) were obtained at 70/75 kVp for all phantom thicknesses. As tube potential increased the IQ was also shown to decrease. ED showed a statistically significant increase (p < 0.001) with increasing phantom thicknesses. CONCLUSION Higher EDs were evident when applying lower tube potentials. Using an AEC with high tube potentials (105/110 kVp) can lead to a considerable decrease in ED with acceptable IQ when undertaking upper abdomen radiography on patients with large body part thicknesses. IMPLICATION FOR PRACTICE Applying higher values of tube potentials for patients who have a thicker abdomen can lead to decreased ED.
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Affiliation(s)
- Kholoud Alzyoud
- Department of Medical Imaging, Faculty of Applied Health Science, The Hashemite University, P.O. Box 330127, Zarqa, 13133, Jordan.
| | - Sadeq Al-Murshedi
- AL-Zahraa University for Women, College of Health and Medical Technology, Karbala, Iraq
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Kawashima H, Ichikawa K, Kitao A, Matsubara T, Sugiura T, Kobayashi T, Kobayashi S. Radiation dose considerations in digital radiography with an anti-scatter grid: A study using adult and pediatric phantoms. J Appl Clin Med Phys 2023; 24:e14081. [PMID: 37491809 PMCID: PMC10476983 DOI: 10.1002/acm2.14081] [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] [Received: 06/19/2022] [Revised: 05/23/2023] [Accepted: 06/08/2023] [Indexed: 07/27/2023] Open
Abstract
BACKGROUND When using an anti-scatter grid, a decrease in receptor dose caused by its X-ray absorption seems to lead to the misperception that radiation dose needs to be increased even in digital radiography (DR). OBJECTIVE To demonstrate that there is no need to increase radiation dose in DR with a grid, based on a visual evaluation using an adult and a pediatric abdomen phantom (PAD and PPD , respectively). MATERIALS AND METHODS Phantom images with and without a grid were obtained with exposure parameters determined based on a preliminarily measured signal-to-noise ratio improvement factor (SIF), an index for potential dose reduction when using a grid. In visual evaluation, four radiologists compared phantom images with a grid applied at different dose reduction rates (0% [no reduction], 18%, 36%, and 59% for PAD and 0% and 11% for PPD ) against an image without a grid at the baseline dose (as the reference). They graded the overall image quality of the former relative to that of the latter (reference) on a 3-point scale (3 = better, 2 = almost equal, 1 = worse). RESULTS The mean scores for dose reduction rates of 0%, 18%, 36%, and 59% were 3.00, 3.00, 2.75, and 1.00, respectively, for PAD ; those for 0% and 11% were 2.13 and 1.63, respectively, for PPD . These results support the validity of our view that no dose increase is necessary when using an anti-scatter grid. Actually, there is even a potential for improvement in image quality with dose reduction rates of ≤36% for PAD . CONCLUSION It is worth reconsidering the necessity of increasing radiation dose in the DR imaging of the adult and pediatric abdomens with an anti-scatter grid.
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Affiliation(s)
- Hiroki Kawashima
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health SciencesKanazawa UniversityKanazawaJapan
| | - Katsuhiro Ichikawa
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health SciencesKanazawa UniversityKanazawaJapan
| | - Azusa Kitao
- Department of RadiologyKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Takashi Matsubara
- Department of RadiologyKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Takumi Sugiura
- Department of RadiologyKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Tomohiro Kobayashi
- Department of RadiologyKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Satoshi Kobayashi
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health SciencesKanazawa UniversityKanazawaJapan
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E A, A Y, T O. Effect of varying X-ray tube voltage and additional filtration on image quality and patient dose in digital radiography system. Appl Radiat Isot 2023; 199:110893. [PMID: 37321050 DOI: 10.1016/j.apradiso.2023.110893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/16/2023] [Accepted: 06/04/2023] [Indexed: 06/17/2023]
Abstract
This study investigated the effect of varying x-ray tube voltage and additional filtration thicknesses on radiation dose and image quality in digital radiography system. The polymethylmethacrylate (PMMA) phantoms of different thicknesses simulating both the adult chest and abdomen and the pediatric patient's chest examinations were used. X-ray tube voltage range of 70-125 kVp was used for adult patient chest radiography, 70-100 kVp for adult patient abdominal radiography, and 50-70 kVp for pediatric 1-year-old chest examination. 0.1-0.3 mm Cu and 1.0 mm Al filters were used as additional filters. Patient doses were measured with an ionization chamber, considering the irradiation parameters recommended for radiographic examinations performed in radiology clinics in the EUR 16260 protocol. The Entrance Skin Dose (ESD) was calculated from the air kerma value measured at the entrance surface of the PMMA phantoms. Effective dose values were calculated by employing PCXMC 2.0 program. For image quality evaluations, CDRAD, LCD-4, Beam stop and Huttner test object used together with PMMA phantoms and Alderson RS-330 Lung/Chest phantom were used. Figure of Merit (FOM), which allows quantitative assessment in terms of image quality and patient dose, has been calculated. Based on the calculated FOM values were evaluated at the tube voltages and additional filter thicknesses recommended in the EUR 16260 protocol. Entrance Skin Dose and Inverse Image Quality Figure (IQFinv) value obtained from contrast detail analysis decreased with increasing filter thickness and tube voltage. Decrease in ESD and IQFinv with increasing tube voltage without additional filter was 56% and 21% for adult chest radiography, 69% and 39% for adult abdominal radiography and 34% and 6% for 1-year-old pediatric chest radiography. When calculated FOM values are examined, it can be recommended to use a 0.1 mm Cu filter at 90 kVp and a 0.1 mm Cu + 1.0 mm Al filter at 125 kVp for adult chest radiography. For adult abdominal radiography, 0.2 mm Cu filter at 70 and 80 kVp and 0.1 mm Cu filter at 90 and 100 kVp were found to be appropriate. It was determined that the appropriate additional filter at 70 kVp for 1-year-old chest radiography was 1.0 mm Al+0.1 mm Cu.
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Affiliation(s)
- Aksit E
- Ankara University, Institute of Nuclear Sciences, 06100, Ankara, Türkiye
| | - Yalcin A
- Ankara University, Institute of Nuclear Sciences, 06100, Ankara, Türkiye
| | - Olgar T
- Ankara University, Institute of Nuclear Sciences, 06100, Ankara, Türkiye; Ankara University, Faculty of Engineering, Department of Physics Engineering, 06100, Ankara, Türkiye.
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Siraj M, Dalah EZ, Okasha MH, Abdel Kader GI, Mohamed Said MS, Kalanter RA, Razack HA, Mohamad Ahmad AN, Albastaki AA. Potentials of additional copper filtration on radiation dose and image quality for adults underwent digital chest X-ray imaging in Dubai Health Authority - UAE. Radiography (Lond) 2023; 29:552-556. [PMID: 36958232 DOI: 10.1016/j.radi.2023.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/25/2023]
Abstract
OBJECTIVE To explore the potentials of adding copper (Cu) filter on image quality and patient dose of adult patients underwent chest X-ray examination METHODS: Patients were divided into four groups. Group 1, patients were exposed with no added Cu filter (standard or control), group 2 a 0.1 mm Cu filter was added, group 3 acquired with 0.2 mm Cu filter and group 4 performed with 0.3 mm Cu filter. Exposure index (EI), entrance surface dose (ESD) and dose area product (DAP) were recorded from the modality and retrospectively analyzed. The visual grading analysis score (VGAS) was used to evaluate image quality. Mann-Whitney T-Test and one-way ordinary ANOVA Test were used to evaluate statistical differences including gender-based findings. RESULTS EI, ESD and DAP data for a total of 784 patients (422 male and 362 female) that underwent indirect digital chest radiography exam were collected. Image quality was maintained when adding 0.1 mm Cu filter achieved with ∼19% DAP reduction. Female showed a significant DAP reduction comparing to male registered in the same group. CONCLUSIONS Reducing dose when using indirect digital chest radiography is possible with no trade-off on image quality. No loss of image quality was reported, images were broadly comparable. IMPLICATIONS FOR PRACTICE This study highlights the importance of utilizing the additional copper filter in digital chest radiography.
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Affiliation(s)
- M Siraj
- PHC-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates.
| | - E Z Dalah
- HQ-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates; College of Medicine, Mohammed Bin Rashid University, Dubai, United Arab Emirates.
| | - M H Okasha
- PHC-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates.
| | - G I Abdel Kader
- PHC-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates.
| | - M S Mohamed Said
- PHC-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates.
| | - R A Kalanter
- HQ-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates.
| | - H A Razack
- PHC-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates.
| | - A N Mohamad Ahmad
- PHC-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates.
| | - A A Albastaki
- PHC-Diagnostic Imaging Department, DAHC, Dubai, United Arab Emirates.
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Dose optimization and image quality measurement in digital abdominal radiography. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Zeng D, Zeng C, Zeng Z, Li S, Deng Z, Chen S, Bian Z, Ma J. Basis and current state of computed tomography perfusion imaging: a review. Phys Med Biol 2022; 67. [PMID: 35926503 DOI: 10.1088/1361-6560/ac8717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 08/04/2022] [Indexed: 12/30/2022]
Abstract
Computed tomography perfusion (CTP) is a functional imaging that allows for providing capillary-level hemodynamics information of the desired tissue in clinics. In this paper, we aim to offer insight into CTP imaging which covers the basics and current state of CTP imaging, then summarize the technical applications in the CTP imaging as well as the future technological potential. At first, we focus on the fundamentals of CTP imaging including systematically summarized CTP image acquisition and hemodynamic parameter map estimation techniques. A short assessment is presented to outline the clinical applications with CTP imaging, and then a review of radiation dose effect of the CTP imaging on the different applications is presented. We present a categorized methodology review on known and potential solvable challenges of radiation dose reduction in CTP imaging. To evaluate the quality of CTP images, we list various standardized performance metrics. Moreover, we present a review on the determination of infarct and penumbra. Finally, we reveal the popularity and future trend of CTP imaging.
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Affiliation(s)
- Dong Zeng
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Cuidie Zeng
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Zhixiong Zeng
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Sui Li
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Zhen Deng
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Sijin Chen
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Zhaoying Bian
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Jianhua Ma
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
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Usefulness of an Additional Filter Created Using 3D Printing for Whole-Body X-ray Imaging with a Long-Length Detector. SENSORS 2022; 22:s22114299. [PMID: 35684921 PMCID: PMC9185553 DOI: 10.3390/s22114299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/31/2022] [Accepted: 06/04/2022] [Indexed: 02/05/2023]
Abstract
We recently developed a long-length detector that combines three detectors and successfully acquires whole-body X-ray images. Although the developed detector system can efficiently acquire whole-body images in a short time, it may show problems with diagnostic performance in some areas owing to the use of high-energy X-rays during whole-spine and long-length examinations. In particular, during examinations of relatively thin bones, such as ankles, with a long-length detector, the image quality deteriorates because of an increase in X-ray transmission. An additional filter is primarily used to address this limitation, but this approach imposes a higher load on the X-ray tube to compensate for reductions in the radiation dose and the problem of high manufacturing costs. Thus, in this study, a newly designed additional filter was fabricated using 3D printing technology to improve the applicability of the long-length detector. Whole-spine anterior–posterior (AP), lateral, and long-leg AP X-ray examinations were performed using 3D-printed additional filters composed of 14 mm thick aluminum (Al) or 14 mm thick Al + 1 mm thick copper (Cu) composite material. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and radiation dose for the acquired X-ray images were evaluated to demonstrate the usefulness of the filters. Under all X-ray inspection conditions, the most effective data were obtained when the composite additional filter based on a 14 mm thick Al + 1 mm thick Cu material was used. We confirmed that an SNR improvement of up to 46%, CNR improvement of 37%, and radiation dose reduction of 90% could be achieved in the X-ray images obtained using the composite additional filter in comparison to the images obtained with no filter. The results proved that the additional filter made with a 3D printer was effective in improving image quality and reducing the radiation dose for X-ray images obtained using a long-length detector.
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Ou X, Chen X, Xu X, Xie L, Chen X, Hong Z, Bai H, Liu X, Chen Q, Li L, Yang H. Recent Development in X-Ray Imaging Technology: Future and Challenges. RESEARCH (WASHINGTON, D.C.) 2021; 2021:9892152. [PMID: 35028585 PMCID: PMC8724686 DOI: 10.34133/2021/9892152] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 11/23/2021] [Indexed: 11/18/2022]
Abstract
X-ray imaging is a low-cost, powerful technology that has been extensively used in medical diagnosis and industrial nondestructive inspection. The ability of X-rays to penetrate through the body presents great advances for noninvasive imaging of its internal structure. In particular, the technological importance of X-ray imaging has led to the rapid development of high-performance X-ray detectors and the associated imaging applications. Here, we present an overview of the recent development of X-ray imaging-related technologies since the discovery of X-rays in the 1890s and discuss the fundamental mechanism of diverse X-ray imaging instruments, as well as their advantages and disadvantages on X-ray imaging performance. We also highlight various applications of advanced X-ray imaging in a diversity of fields. We further discuss future research directions and challenges in developing advanced next-generation materials that are crucial to the fabrication of flexible, low-dose, high-resolution X-ray imaging detectors.
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Affiliation(s)
- Xiangyu Ou
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Xue Chen
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Xianning Xu
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Lili Xie
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Xiaofeng Chen
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Zhongzhu Hong
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Hua Bai
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Xiaowang Liu
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Qiushui Chen
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
| | - Lin Li
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Huanghao Yang
- MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
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Kawashima H, Ichikawa K, Iida Y. A new stationary grid, with grid lines aligned to pixel lines with submicron-order precision, to suppress grid artifacts. Med Phys 2021; 48:4935-4943. [PMID: 34270103 DOI: 10.1002/mp.15099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 06/25/2021] [Accepted: 06/28/2021] [Indexed: 11/10/2022] Open
Abstract
PURPOSE We have developed a new stationary grid named a pixel-aligned grid (PA grid), in which the grid lines are aligned to the pixel lines with submicron-order precision. Further, we have evaluated its performance relative to that of a conventional grid combined with grid-line removal (GLR) processing. METHODS A flat-panel detector system of an indirect type, with a pixel pitch of 150 μm, was employed. Four PA grids having a grid ratio of 6:1 associated with abdominal bedside radiography, with the grid-line pitch (GP) varied around the target value of 150 μm, were produced. Blank images were obtained with four PA grids for measuring the period and amplitude of the grid artifact. In performance evaluation, acrylic and anthropomorphic abdominal phantom images were used with the PA grid, a conventional grid (40 lines/cm, grid ratio 6:1), and no grids. The grid artifacts were evaluated by power spectrum (PS) analysis. Also, the signal-to-noise ratio (SNR) improvement factor (KSNR ) was measured. RESULTS Grid artifacts were hardly recognizable with PA grids with GP errors of 0.3 μm and 0.6 μm because of the prolonged grid artifact periods. The measured artifact amplitudes of these PA grids were less than 0.6%. Furthermore, the PA grids did not produce notable frequency peaks in PS. In contrast, the conventional grid without GLR processing produced two conspicuous peaks. With GLR processing, notable reductions in PS were observed around the two peak frequencies, which caused blurring in bone structures. For the acrylic thickness of 20 cm, the KSNR s for the PA grid were around 1.4, suggesting some SNR improvement in abdominal bedside radiography. CONCLUSION The present study has demonstrated that PA grids with their grid-line pitches close to the pixel-line pitch within errors of 0.6 μm produce grid artifact-free images without any signal losses. Thus, the proposed PA grid will prove to be effective and useful in various clinical applications.
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Affiliation(s)
- Hiroki Kawashima
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Katsuhiro Ichikawa
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Yasuko Iida
- Mitaya Manufacturing Co., Ltd., Kawagoe, Japan
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Fujikawa K, Osaki T, Nakagawa H, Kikuchi K, Kiriki M, Wada Y, Miki R, Kotoura N. [Usefulness of Combining Post-processing Scatter Correction and an Anti-scatter Grid in Chest Standing Radiography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:555-563. [PMID: 34148897 DOI: 10.6009/jjrt.2021_jsrt_77.6.555] [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] [Indexed: 11/11/2022]
Abstract
PURPOSE The aim of this study was to evaluate the usefulness of combining post-processing scatter correction (IG) and an anti-scatter grid (RG) in chest radiography. METHOD To determine the combination protocol (Hyb) that was closed to RG 12:1 (RG12), we measured the content rate of scattered radiation for each combination (RG12, IG12, RG3-12+IG3-12). Task-based modulation transfer function (MTF_Task) and SDNR were evaluated using RG12, IG12, and Hyb. Additionally, seven radiologists performed visual evaluation by using chest phantom. RESULT The protocol of Hyb was RG8+IG3. In SDNR, Hyb (RG8+IG3) was equal to or higher than RG12, and MTF_Task was equal in all grid systems. Hyb (RG8+IG3) was significantly superior to RG12 in visual evaluation. CONCLUSION The combining post-processing scatter correction should be useful for improving inspection throughput and reducing the risk of grid's damage.
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Affiliation(s)
- Keita Fujikawa
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
| | - Takao Osaki
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
| | - Hideo Nakagawa
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
| | - Keisuke Kikuchi
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
| | - Masato Kiriki
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
| | - Yuya Wada
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
| | - Ryosuke Miki
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
| | - Noriko Kotoura
- Department of Radiological Technology, Hyogo College of Medicine College Hospital
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Maruyama S, Saito H, Shimosegawa M. Characterization of anti-scatter grids via a modulation transfer function improvement factor using an edge device. Biomed Phys Eng Express 2021; 7. [PMID: 33906178 DOI: 10.1088/2057-1976/abfc2f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 04/27/2021] [Indexed: 11/12/2022]
Abstract
In optimizing the imaging conditions, changes in image quality due to scattered radiation are important evaluation targets. This study focuses on the evaluation of the image quality improvement characteristics obtained using anti-scatter grids in digital x-ray imaging, and proposes a frequency-dependent modulation transfer function (MTF) improvement factor,MIFG(u),as a new evaluation index. Accordingly, the purpose of this study is to clarify the validity and the usefulness of this proposed index in the performance evaluation of grids. The proposedMIFG(u)method is applied to evaluate several types of grids with different grid densities and ratios, and the characteristics of grids exhibiting different performances are examined. The proposed index is calculated based on the MTF measurement by using an edge test device. The results show thatMIFG(u)changed according to grid type and scatter conditions. In particular, a remarkable difference was observed in the high scatter condition compared with the low condition.MIFG(u)in the vertical direction with regards to the absorbing strips shows a peak at 0.2-0.5 cycles/mm and be a constant value from approximately 1 cycle/mm; whileMIFG(u)in the parallel direction is a constant value with respect to changes in spatial frequency. It is shown thatMIFG(u)could be used to accurately describe the characteristics of a grid under different imaging conditions. We believe that the use of the proposed index could expand the options for optimizing imaging conditions when using grids.
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Affiliation(s)
- Sho Maruyama
- School of Radiological Sciences, Faculty of Health Science, Gunma Paz University, Gunma, Japan.,Graduate School of Radiological Technology, Gunma Prefectural College of Health Sciences, Gunma, Japan
| | - Hiroki Saito
- School of Radiological Sciences, Faculty of Health Science, Gunma Paz University, Gunma, Japan
| | - Masayuki Shimosegawa
- Graduate School of Radiological Technology, Gunma Prefectural College of Health Sciences, Gunma, Japan
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15
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Kawashima H, Ichikawa K, Kunitomo H. [Relationship between Radiation Quality and Image Quality in Digital Chest Radiography: Validation Study Using Human Soft Tissue-equivalent Phantom]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:255-262. [PMID: 33746173 DOI: 10.6009/jjrt.2021_jsrt_77.3.255] [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 To evaluate image quality for chest radiography at different radiation qualities, using phantoms with scatter fractions similar to those of lungs. METHODS Two base phantoms with 10 and 4 cm thicknesses, respectively, made of a soft tissue-equivalent material, were used to mimic the X-ray attenuation of the human lung. Two plates with soft tissue- and bone-equivalent materials, respectively, were placed on the base phantom as contrast objects. The image data were obtained with the same entrance surface dose in each radiation quality. Six radiation qualities generated using 120 and 90 kV, and additional copper filters with thicknesses 0, 0.1, and 0.2 mm were selected. The signal-difference-to-noise ratio (SdNR) and a contrast ratio of the soft tissue to the bone were measured for the six radiation qualities. RESULTS The thicker the additional filter, the better the SdNR at both tube voltages. The SdNR values were not significantly different between 120 and 90 kV for the same filter thickness. The contrast ratio was higher at 120 than at 90 kV by approximately 8%. CONCLUSIONS Because of the advantage of the contrast ratio and the highest SdNR, the radiation quality with 120 kV and 0.2-mm copper filtration was the best. It was indicated that the conventional tube voltage of 120 kV remains to be better than the lower tube voltage of 90 kV.
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Affiliation(s)
- Hiroki Kawashima
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University
| | - Katsuhiro Ichikawa
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University
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Kaushik C, Sandhu IS, Srivastava AK, Chitkara M. ESTIMATION OF ENTRANCE SURFACE AIR KERMA IN DIGITAL RADIOGRAPHIC EXAMINATIONS. RADIATION PROTECTION DOSIMETRY 2021; 193:16-23. [PMID: 33683324 DOI: 10.1093/rpd/ncab018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 01/10/2021] [Accepted: 01/31/2021] [Indexed: 06/12/2023]
Abstract
PURPOSE Contribution of radiation doses from medical X-ray examination to collective dose is significant. Unusually, high doses may increase the risk of stochastic effects of radiations. Therefore, radiation dose assessment was performed in 241 digital X-ray examinations in the study and was compared with published dose reference levels (DRLs). METHODS Entrance surface air kerma (ESAK) was calculated in chest PA, cervical AP/Lat, abdomen AP, lumbar AP/Lat and pelvis AP digital radiographic examinations (119 male and 122 female) following the International Atomic Energy Agency recommended protocol. Initially, 270 digital examinations were selected, reject analysis was performed and final 241 examinations were enrolled in the study for dose calculations. The exposure parameters and X-ray tube output were used for dose calculations. Effective doses were estimated with the help of conversion coefficients from ICRP 103. RESULTS Median ESAK (mGy) and associated effective doses obtained were cervical spine AP (1.30 mGy, 0.045 mSv), cervical spine Lat (0.25 mGy, 0.005 mSv), chest PA (0.11 mGy, 0.014 mSv), abdomen AP (0.90 mGy, 0.118 mSv), lumbar spine AP (1.52 mGy, 0.177 mSv), lumbar spine Lat (7.76 mGy, 0.209 mSv) and pelvis AP (0.82 mGy, 0.081 mSv). Results were compared with the studies of UK, Oman, India and Canada. CONCLUSION The calculated ESAK and effective dose values were less than or close to previously published literature except for cervical spine AP and lumbar spine Lat. The results reinforce the need for radiation protection optimization, improving examination techniques and appropriate use of automatic exposure control in digital radiography. ESAK values reported in this study could further contribute to establishing local DRLs, regional DRLs and national DRLs.
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Affiliation(s)
- Chanchal Kaushik
- Chitkara School of Health Sciences, Chitkara University, Punjab, India
| | - Inderjeet Singh Sandhu
- Chitkara University Institute of Engineering & Technology, Chitkara University, Punjab, India
| | - A K Srivastava
- Department of Radiology, University College of Medical Sciences, Delhi, India
| | - Mansi Chitkara
- Chitkara University Institute of Engineering & Technology, Chitkara University, Punjab, India
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17
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Kunitomo H, Ichikawa K. Signal-to-noise ratio improvements using anti-scatter grids with different object thicknesses and tube voltages. Phys Med 2020; 73:105-110. [DOI: 10.1016/j.ejmp.2020.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 02/29/2020] [Accepted: 04/15/2020] [Indexed: 10/24/2022] Open
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Lai ZH, Sá Dos Reis C, Sun Z. Effective dose and image optimisation of lateral lumbar spine radiography: a phantom study. Eur Radiol Exp 2020; 4:13. [PMID: 32056045 PMCID: PMC7018898 DOI: 10.1186/s41747-019-0132-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 11/05/2019] [Indexed: 11/22/2022] Open
Abstract
Background To investigate lateral lumbar spine radiography technical parameters for reduction of effective dose whilst maintaining image quality (IQ). Methods Thirty-six radiograms of an anthropomorphic phantom were acquired using different exposure parameters: source-to-detector distance (SDD) (100, 130 or 150 cm), tube potential (75, 85 or 95 kVp), tube current × exposure time product (4.5, 9, 18 mAs) and additional copper (Cu) filter (no filter, 0.1-, 0.2-, or 0.3-mm thickness. IQ was assessed using an objective approach (contrast-to-noise-ratio [CNR] calculation and magnification measurement) and a perceptual approach (six observers); ED was estimated using the PCXMC 2.0 software. Descriptive statistics, paired t test, and intraclass correlation coefficient (ICC) were used. Results The highest ED (0.022 mSv) was found with 100 cm SSD, 75 kVp, 18 mAs, and without Cu filter, whilst the highest CNR (7.23) was achieved at 130 cm SSD, 75 kVp, 18 mAs, and without Cu filter. The lowest ED and CNR were generated at 150 cm SDD, 95 kVp, 4.5 mAs, and 0.3-mm Cu filter. All observers identified the relevant anatomical structures on all images with the lowest ED and IQ. The intra-observer (0.61–0.79) and inter-observer (0.55–0.82) ICC ranged from moderate to excellent. Conclusion All relevant anatomical structures were identified on the lateral lumbar spine radiographs despite using low-dose protocols. The lowest ED (0.002 mSv) was obtained with 150 cm SDD, 95 kVp, 4.5 mAs, and 0.3-mm Cu filter. Further technical and clinical studies are needed to verify these preliminary findings.
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Affiliation(s)
- Zer Hau Lai
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, 6845, Australia
| | - Cláudia Sá Dos Reis
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, 6845, Australia. .,School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Av. de Beaumont 21, 1011, Lausanne, Switzerland. .,NOVA National School of Public Health, Public Health Research Centre, Universidade NOVA de Lisboa, Lisbon, Portugal.
| | - Zhonghua Sun
- Discipline of Medical Radiation Sciences, School of Molecular and Life Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, 6845, Australia
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Jeukens CRLPN, Kütterer G, Kicken PJ, Frantzen MJ, van Engelshoven JMA, Wildberger JE, Kemerink GJ. Gonad shielding in pelvic radiography: modern optimised X-ray systems might allow its discontinuation. Insights Imaging 2020; 11:15. [PMID: 32030539 PMCID: PMC7005227 DOI: 10.1186/s13244-019-0828-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 12/10/2019] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE As gonad shielding is currently under debate, this study evaluates the practice, from its introduction in about 1905 until today. METHODS The literature was searched for developments in shielding and insights into the effects of ionising radiation on gonads. Based on own pre-1927 dose reconstructions, reported doses after 1927, a 2015-report from the European Union and recent own measurements, the effects of technological evolution and optimisation on radiation dose and hereditary risk were assessed. RESULTS In the 1900s, gonad shielding was first applied to prevent male sterility, but was discontinued when instrumental developments led to reduced radiation doses. In the 1950s, concerns about hereditary risks intensified and gonad shielding was recommended again, becoming routine worldwide. Imaging-chain improvements over time were considerable: in 2018, the absorbed dose was 0.5% of its 1905 value for the testes and 2% for the ovaries, our optimised effective dose a factor five lower than the value corresponding to the current EU diagnostic reference level, and the reduction in detriment-adjusted risk by shielding less than 1 × 10-6 for women and 5 × 10-6 for men. CONCLUSIONS Assessment of pelvic doses revealed a large reduction in radiation risks facilitated by technological developments. Optimisation likewise contributed, but unfortunately, its potential was never adequately exploited. Today, using a modern and optimised X-ray system, gonad shielding can be safely discontinued for women. For men, there might be a marginal benefit, but potential negative side-effects may well dominate. Discontinuation of gonad shielding seems therefore justifiable.
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Affiliation(s)
- Cécile R L P N Jeukens
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P. Debijelaan 25, 6229 HX, Maastricht, The Netherlands.
| | - Gerhard Kütterer
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P. Debijelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Pierre J Kicken
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P. Debijelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Marij J Frantzen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P. Debijelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Jos M A van Engelshoven
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P. Debijelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P. Debijelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Gerrit J Kemerink
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P. Debijelaan 25, 6229 HX, Maastricht, The Netherlands
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20
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Kang H, Lee ES, Park HJ, Park BK, Park JY, Suh SW. Abdominal Digital Radiography with a Novel Post-Processing Technique: Phantom and Patient Studies. JOURNAL OF THE KOREAN SOCIETY OF RADIOLOGY 2020; 81:920-932. [PMID: 36238179 PMCID: PMC9432201 DOI: 10.3348/jksr.2020.81.4.920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 10/09/2019] [Accepted: 10/18/2019] [Indexed: 11/15/2022]
Abstract
Purpose Materials and Methods Results Conclusion
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Affiliation(s)
- Hyein Kang
- Department of Radiology, Chung-Ang University Hospital, Seoul, Korea
| | - Eun Sun Lee
- Department of Radiology, Chung-Ang University Hospital, Seoul, Korea
- College of Medicine, Chung-Ang University, Seoul, Korea
| | - Hyun Jeong Park
- Department of Radiology, Chung-Ang University Hospital, Seoul, Korea
- College of Medicine, Chung-Ang University, Seoul, Korea
| | - Byung Kwan Park
- College of Medicine, Chung-Ang University, Seoul, Korea
- Department of Surgery, Chung-Ang University Hospital, Seoul, Korea
| | - Jae Yong Park
- College of Medicine, Chung-Ang University, Seoul, Korea
- Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea
| | - Suk-Won Suh
- College of Medicine, Chung-Ang University, Seoul, Korea
- Department of Surgery, Chung-Ang University Hospital, Seoul, Korea
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21
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Kawashima H, Ichikawa K, Hanaoka S, Matsubara K. Optimizing image quality using automatic exposure control based on the signal-difference-to-noise ratio: a phantom study. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2019; 42:803-810. [PMID: 31396856 DOI: 10.1007/s13246-019-00784-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 10/26/2022]
Abstract
This study proposes to adjust the sensitivity of automatic exposure control (AEC) for achieving consistent image quality over a range of subject thicknesses in abdominal radiography simulations. The relation between image quality and subject thickness was investigated using a digital radiography system with 10-, 15-, 20-, and 25-cm-thick acrylic phantom. Simple pixel signal-to-noise ratio (SNR) was measured to check the default AEC accuracy for each thickness, and image quality was evaluated using the signal-difference-to-noise ratio (SDNR) with an additional acrylic plate and bone-equivalent material. Based on the figure of merit theory, dose ratios to obtain constant image quality regardless of the subject thickness were calculated from SDNR results. The AEC setup was manually modified using this dose ratio, and visibility was examined using a CDRAD 2.0 contrast-detail analysis phantom. Moreover, the entrance surface dose (ESD) was estimated as an index of exposure dose using exposure parameters. The default AEC setup provided a constant simple pixel SNR for each subject thickness with a high accuracy. SDNRs decreased with an increase in the subject thickness. The calculated dose ratios relative to the results for 20 cm thickness were 0.424, 0.647, and 1.43 for 10, 15 and 25 cm, respectively, and a > 25% decrease in ESD was observed for smaller patients. CDRAD analysis using the modified AEC setup showed almost identical visibility for each thickness. Adjusting the sensitivity of AEC according to subject thickness can contribute toward the optimization of the exposure condition.
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Affiliation(s)
- Hiroki Kawashima
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Japan.
| | - Katsuhiro Ichikawa
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Japan
| | - Shinsuke Hanaoka
- Radiology Division, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, 920-8641, Japan
| | - Kosuke Matsubara
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Japan
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22
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Metaxas VI, Messaris GA, Lekatou AN, Petsas TG, Panayiotakis GS. PATIENT DOSES IN COMMON DIAGNOSTIC X-RAY EXAMINATIONS. RADIATION PROTECTION DOSIMETRY 2019; 184:12-27. [PMID: 30289498 DOI: 10.1093/rpd/ncy169] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/18/2018] [Accepted: 09/05/2018] [Indexed: 05/28/2023]
Abstract
A local survey was conducted, to evaluate the radiation dose to adult patients who underwent diagnostic X-ray examinations. Patient-related and technical data were recorded, in 1504 patients, for each of the 11 individual projections, of the 7 most common examinations performed in an X-ray room, with 1 digital radiography system. The patient entrance surface air kerma (ESAK) and the effective dose (ED) were calculated based on the X-ray tube output and the exposure parameters, as well as utilisation of suitable conversion coefficients, respectively. The 75th percentiles of the distribution of the ESAK and kerma area product (KAP) values were also established. The mean, median and 75th percentiles were compared with the national reference levels and the most common values reported at the European level through the DOSE DATAMED II project. The corresponding ED values were also compared with the average values reported for all European countries. The mean ESAK, KAP and ED values along with the uncertainty U values for chest PA, chest LAT, cranium AP, cranium LAT, cervical spine AP, cervical spine LAT, lumbar spine AP, lumbar spine LAT, pelvis AP, abdomen AP, kidneys and urinary bladder (KUB) AP were 0.12 (0.001) mGy, 0.66 (0.023) mGy, 1.01 (0.034) mGy, 0.69 (0.098) mGy, 0.72 (0.014) mGy, 0.63 (0.011) mGy, 4.12 (0.050) mGy, 5.74 (0.082) mGy, 2.57 (0.024) mGy, 1.94 (0.017) mGy, 2.47 (0.073) mGy, and 0.09 (0.001) Gy cm2, 0.38 (0.012) Gy cm2, 0.32 (0.009) Gy cm2, 0.27 (0.052) Gy cm2, 0.17 (0.004) Gy cm2, 0.21 (0.006) Gy cm2, 1.18 (0.018) Gy cm2, 1.86 (0.023) Gy cm2, 1.41 (0.012) Gy cm2, 1.27 (0.010) Gy cm2, 1.28 (0.038) Gy cm2, as well as 0.01 (0.0001) mSv, 0.05 (0.0016) mSv, 0.02 (0.0006) mSv, 0.01 (0.0012) mSv, 0.03 (0.0008) mSv, 0.03 (0.0006) mSv, 0.26 (0.0038) mSv, 0.17 (0.0022) mSv, 0.20 (0.0016) mSv, 0.23 (0.0018) mSv, 0.23 (0.0068) mSv, respectively. The 75th percentiles along with the uncertainty U values for chest PA, chest LAT, cranium AP, cranium LAT, cervical spine AP, cervical spine LAT, lumbar spine AP, lumbar spine LAT, pelvis AP, abdomen AP, kidneys and urinary bladder (KUB) AP were 0.14 (0.006) mGy, 0.88 (0.031) mGy, 1.22 (0.049) mGy, 0.94 (0.098) mGy, 0.93 (0.027) mGy, 0.78 (0.013) mGy, 5.16 (0.073) mGy, 7.24 (0.134) mGy, 2.96 (0.047) mGy, 2.59 (0.036) mGy, 3.07 (0.116) mGy, as well as 0.10 (0.0006) Gy cm2, 0.51 (0.017) Gy cm2, 0.37 (0.020) Gy cm2, 0.33 (0.040) Gy cm2, 0.23 (0.007) Gy cm2, 0.26 (0.011) Gy cm2, 1.50 (0.036) Gy cm2, 2.26 (0.035) Gy cm2, 1.61 (0.023) Gy cm2, 1.67 (0.017) Gy cm2, 1.56 (0.069) Gy cm2, in terms of ESAK and KAP values, respectively. The results were significantly lower compared with the national reference levels, the most common DRL values reported at the European level and other previously reported dose values. Patient dose surveys could contribute towards optimising radiation protection for patients, therefore, highlighting the necessity to increase the awareness and knowledge of the radiation dose in conjunction with the required image quality.
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Affiliation(s)
- Vasileios I Metaxas
- Department of Medical Physics, School of Medicine, University of Patras, Patras, Greece
| | - Gerasimos A Messaris
- Department of Medical Physics, School of Medicine, University of Patras, Patras, Greece
| | - Aristea N Lekatou
- Department of Medical Physics, School of Medicine, University of Patras, Patras, Greece
| | - Theodore G Petsas
- Department of Radiology, School of Medicine, University of Patras, Patras, Greece
| | - George S Panayiotakis
- Department of Medical Physics, School of Medicine, University of Patras, Patras, Greece
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Dose Reduction Protocol for Full Spine X-ray Examination Using Copper Filters in Patients With Adolescent Idiopathic Scoliosis. Spine (Phila Pa 1976) 2019; 44:203-210. [PMID: 30005046 DOI: 10.1097/brs.0000000000002787] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A prospective case series. OBJECTIVE The aim of this study was to assess a new protocol for full spine X-ray using copper (Cu) filters to reduce radiation exposure in patients with adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA Radiation exposure is associated with an increased risk of cancer development in children. To reduce the radiation exposure without compromising the image quality using existing radiographic equipment, a new computed radiography protocol was optimized using a variety of heavy metal filters. METHODS Study 1: Whole spine radiographs were obtained using a human body phantom, and radiation doses without and with 0.1, 0.2, and 0.3 mm thick Cu filters were compared. Study 2: Patients with AIS who underwent posterior fusion were radiographically evaluated at follow-ups; the X-ray protocols with or without the use of 0.2-mm Cu filters were alternated between consecutive follow-ups. The image quality was independently evaluated using six points in the anterior-posterior (AP) view and seven in the lateral [left-right (LR)] view by three spine surgeons using a three-point grading system. RESULTS Study 1: The surface doses while obtaining nonfiltered X-rays in AP and LR views were 0.31 and 0.93 mGy, respectively, whereas those with 0.1-, 0.2-, and 0.3-mm Cu filters were 0.16 and 0.52, 0.11 and 0.36, and 0.08 and 0.27 mGy, respectively.Study 2: In patients with AIS, the percentage of grade 3 scores (both endplates were identifiable) on AP-view images was 85% with nonfiltered X-rays and 75% with the filtered X-rays. However, there were no significant differences between the two protocols. On LR images, the frequency of grade 3 scores was significantly lower at Th2 and Th12 on filtered images than on nonfiltered ones. CONCLUSION Whole spine radiographs using 0.2-mm Cu filters in patients with AIS could reduce radiation exposure more than 60% while preserving the image quality. LEVEL OF EVIDENCE 4.
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Homolka P, Figl M. Equivalent thicknesses of beam hardening filters consisting of aluminium, copper, Al/Cu and Al/Gold combinations and plumbiferous acrylic for 40 to 150 kVp diagnostic spectra. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2018; 38:1269-1283. [PMID: 30115815 DOI: 10.1088/1361-6498/aadaf4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
PURPOSE Beam hardening filters used to reduce patient doses typically consist of aluminium, copper, or a combination of both. Optically transparent filters containing lead in plumbiferous acrylic became available. One vendor also uses a combination of aluminium and gold. Data is provided to compare filter thicknesses in terms of half-value layer (HVL) for clinically relevant kVp. METHODS Equivalent filter thicknesses were defined by identical kVp and 1st HVL. Equivalent copper filter thicknesses were calculated for aluminium and typical filters found in radiographic and interventional systems. A verified semi-empirical spectrum calculation programme and National Institute of Standards and Technology (NIST) mass attenuation coefficients were applied. Lead acrylic filters were simulated by a two-component model of acrylic plus lead with mass thicknesses determined by matching 1 HVLs in Al at RQR5 using filter specifications. RESULTS Coefficients are provided to convert mm Cu to mm Al and vice versa for tube potentials from 40 to 150 kVp. 1 mm Al corresponds to 27.8 ± 1 μm Cu over the entire energy range simulated. Using this simple model as opposed to simulations of all individual filters made from Al/Cu combinations (1 and 2 mm Al, 1 Al + 0.1 and 0.2 Cu, 1.5 Al plus 0.3 and 0.6 Cu, 2 Al plus 0.1 Cu) for the entire energy range results in differences in equivalent Cu thicknesses below 4 μm Cu (3 μm for 50-150 kVp). kVp dependence is larger for filters containing larger Z elements. 1 mm Al plus 10 μm gold used by Shimadzu corresponds to 75-80 μm Cu, depending on kVp; plumbiferous acrylic with nominal filtrations of 1 Al plus 0.1 Cu, and 1 Al plus 0.2 Cu corresponded to 124-132 μm, and 206-232 μm Cu, respectively. CONCLUSIONS Experimental verification of the equivalence of aluminium and combined aluminium plus copper filters showed excellent agreement between calculated copper equivalent thickness and measurements with copper filters for clinical beams from 40 to 150 kVp.
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Affiliation(s)
- Peter Homolka
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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Tse JJ, Dunmore-Buyze J, Drangova M, Holdsworth DW. Dual-energy computed tomography using a gantry-based preclinical cone-beam microcomputed tomography scanner. J Med Imaging (Bellingham) 2018; 5:033503. [PMID: 30155511 PMCID: PMC6103383 DOI: 10.1117/1.jmi.5.3.033503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 07/30/2018] [Indexed: 11/14/2022] Open
Abstract
Dual-energy microcomputed tomography (DECT) can provide quantitative information about specific materials of interest, facilitating automated segmentation, and visualization of complex three-dimensional tissues. It is possible to implement DECT on currently available preclinical gantry-based cone-beam micro-CT scanners; however, optimal decomposition image quality requires customized spectral shaping (through added filtration), optimized acquisition protocols, and elimination of misregistration artifacts. We present a method for the fabrication of customized x-ray filters-in both shape and elemental composition-needed for spectral shaping. Fiducial markers, integrated within the sample holder, were used to ensure accurate co-registration between sequential low- and high-energy image volumes. The entire acquisition process was automated through the use of a motorized filter-exchange mechanism. We describe the design, implementation, and evaluation of a DECT system on a gantry-based-preclinical cone-beam micro-CT scanner.
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Affiliation(s)
- Justin J Tse
- Western University, Bone and Joint Institute, Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.,Western University, Bone and Joint Institute, Departments of Medical Biophysics and Medical Imaging, London, Ontario, Canada
| | - Joy Dunmore-Buyze
- Western University, Bone and Joint Institute, Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada
| | - Maria Drangova
- Western University, Bone and Joint Institute, Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.,Western University, Bone and Joint Institute, Departments of Medical Biophysics and Medical Imaging, London, Ontario, Canada
| | - David W Holdsworth
- Western University, Bone and Joint Institute, Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.,Western University, Bone and Joint Institute, Departments of Medical Biophysics and Medical Imaging, London, Ontario, Canada.,Western University, Bone and Joint Institute, Department of Surgery, London, Ontario, Canada
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Jang JS, Yang HJ, Koo HJ, Kim SH, Park CR, Yoon SH, Shin SY, Do KH. Image quality assessment with dose reduction using high kVp and additional filtration for abdominal digital radiography. Phys Med 2018; 50:46-51. [PMID: 29891093 DOI: 10.1016/j.ejmp.2018.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 05/04/2018] [Accepted: 05/06/2018] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Dose reduction using additional filters with high kilovoltage peak (kVp) for abdominal digital radiography has received much attention recently. We evaluated image quality with dose reduction in abdominal digital radiography by using high kVp and additional copper filters at a tertiary hospital. METHODS Between June 2016 and July 2016, 82 patients underwent abdominal digital radiography using 80 kVp in X-ray room 1 and 82 were imaged using 92 kVp with 0.1-mm copper filtration in X-ray room 2. The effective dose was calculated using a PC-based Monte Carlo program. Image quality of the abdominal radiography acquired in the two rooms was evaluated using a five-point ordinal scale, as well as the signal-to-noise and contrast-to-noise ratios. RESULTS The mean effective dose decreased by 25.8% and 25.7% for the supine and standing positions, respectively, when abdominal digital radiography using 92 kVp with 0.1-mm copper filtration was performed. In the 20 patients who performed abdominal digital radiography twice in each room, visual grading scores for visualisation of psoas outlines and kidney outlines are higher in room 1. However, there was no statistical significant difference of visual grading scores among the 124 patients who underwent only one abdominal radiography in the room 1 or 2 (P > 0.05). CONCLUSIONS Dose reduction for abdominal digital radiography can be achieved with comparable image quality by performing abdominal digital radiography using 92 kVp with 0.1-mm copper filtration, despite the higher AEC dose.
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Affiliation(s)
- Ji Sung Jang
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea; Department of Medical Physics, Korea University, South Korea
| | - Hyung Jin Yang
- Department of Medical Physics, Korea University, South Korea
| | - Hyun Jung Koo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea
| | - Sung Ho Kim
- Department of Medical Physics, Korea University, South Korea
| | - Chan Rok Park
- Department of Medical Physics, Korea University, South Korea
| | - Suk Hwan Yoon
- Department of Medical Physics, Korea University, South Korea
| | - So Youn Shin
- Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, South Korea
| | - Kyung-Hyun Do
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea.
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