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Samara ET, Saltybaeva N, Sans Merce M, Gianolini S, Ith M. Systematic literature review on the benefit of patient protection shielding during medical X-ray imaging: Towards a discontinuation of the current practice. Phys Med 2022; 94:102-109. [PMID: 35030383 DOI: 10.1016/j.ejmp.2021.12.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/15/2021] [Accepted: 12/28/2021] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Patient shielding during medical X-ray imaging has been increasingly criticized in the last years due to growing evidence that it often provides minimal benefit and may even compromise image quality. In Europe, and as also shown in a short assessment in Switzerland, the use of patient shielding is inhomogeneous. The aim of this study was to systematically review recent literature in order to assess benefits and appraise disadvantages related to the routine use of patient shielding. METHODS To evaluate benefits and disadvantages related to the application of patient shielding in radiological procedures, a systematic literature review was performed for CT, radiography, mammography and fluoroscopy-guided medical X-ray imaging. In addition, reports from medical physics societies and authorities of different countries were considered in the evaluation. RESULTS The literature review revealed 479 papers and reports on the topic, from which 87 qualified for closer analysis. The review considered in- and out-of-plane patient shielding as well as shielding for pregnant and pediatric patients. Dose savings and other dose and non-dose related effects of patient shielding were considered in the evaluation. CONCLUSIONS Although patient shielding has been used in radiological practice for many years, its use is no longer undisputed. The evaluation of the systematic literature review of recent studies and reports shows that dose savings are rather minimal while significant dose- and non-dose-related detrimental effects are present. Consequently, the routine usage of patient protection shielding in medical X-ray imaging can be safely discontinued for all modalities and patient groups.
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Affiliation(s)
- Eleni Theano Samara
- Radiation Protection Unit, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Natalia Saltybaeva
- Radiation Protection Unit, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Marta Sans Merce
- Department of Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland
| | | | - Michael Ith
- Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Inselspital, Bern University Hospital, University of Bern, Switzerland
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Mansouri E, Mesbahi A, Malekzadeh R, Mansouri A. Shielding characteristics of nanocomposites for protection against X- and gamma rays in medical applications: effect of particle size, photon energy and nano-particle concentration. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2020; 59:583-600. [PMID: 32780196 DOI: 10.1007/s00411-020-00865-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
In recent decades, nanomaterials have been extensively investigated for many applications. Composites doped with different metal nanoparticles have been suggested as effective shielding materials to replace conventional lead-based materials. The use of concretes as structural and radiation protective material has been influenced by the addition of nanomaterials. Several elements with high atomic number and density, such as lead, bismuth, and tungsten, have the potential to form nanoparticles that offer significant enhancements in the shielding ability of composites. Their performance for a range of particle concentrations, particle sizes, and photon energies have been investigated. This review is an attempt to gather the data published in the literature about the application of nanomaterials in radiation shielding, including the use of polymer composites and concretes for protection against X-rays and gamma radiation.
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Affiliation(s)
- Elham Mansouri
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Asghar Mesbahi
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
- Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Reza Malekzadeh
- Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ahmad Mansouri
- Department of Materials Engineering, University of Tabriz, 51666-16471, Tabriz, Iran
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Cha H, Lee K, Park MS, Lee KM, Cho K, Sung KH. Shielding effect of radiation dose reduction fiber during the use of C-arm fluoroscopy: a phantom study. JOURNAL OF RADIATION RESEARCH 2020; 61:705-711. [PMID: 32766722 PMCID: PMC7482166 DOI: 10.1093/jrr/rraa060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/01/2020] [Indexed: 06/11/2023]
Abstract
This study evaluated the shielding effect of a newly developed dose-reduction fiber (DRF) made from barium sulfate, in terms of radiation doses delivered to patients' radiosensitive organs and operator during C-arm fluoroscopy and its impact on the quality of images. A C-arm fluoroscopy unit was placed beside a whole-body phantom. Radiophotoluminescent glass dosimeters were attached to the back and front of the whole-body phantom at 20 cm intervals. Radiation doses were measured without DRF and with it applied to the back (position 1), front (position 2) or both sides (position 3) of the phantom. To investigate the impact of DRF on the quality of fluoroscopic images, step-wedge and modulation transfer function phantoms were used. The absorbed radiation doses to the back of the phantom significantly decreased by 25.3-88.8% after applying DRF to positions 1 and 3. The absorbed radiation doses to the front of the phantom significantly decreased by 55.3-93.6% after applying DRF to positions 2 and 3. The contrast resolution values for each adjacent step area fell in the range 0.0119-0.0209, 0.0128-0.0271, 0.0135-0.0339 and 0.0152-0.0339 without and with DRF applied to positions 1, 2 and 3, respectively. The investigated DRF effectively reduces absorbed radiation doses to patients and operators without decreasing the quality of C-arm fluoroscopic images. Therefore, routine clinical use of the DRF is recommended during the use of C-arm fluoroscopy.
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Affiliation(s)
- Hyemi Cha
- Department of Bio-convergence Engineering, Korea University, Seoul, Korea
| | - Kisung Lee
- Department of Bio-convergence Engineering, Korea University, Seoul, Korea
| | - Moon Seok Park
- Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Gyeonggi, Korea
| | - Kyoung Min Lee
- Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Gyeonggi, Korea
| | - Kyeyoung Cho
- Department of Bio-convergence Engineering, Korea University, Seoul, Korea
| | - Ki Hyuk Sung
- Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Gyeonggi, Korea
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Sutanto H, Irdawati Y, Anam C, Fujibuchi T, Dougherty G, Hidayanto E, Arifin Z, Soedarsono JW, Bahrudin. An artifact-free thyroid shield in CT examination: a phantom study. Biomed Phys Eng Express 2020; 6:015029. [DOI: 10.1088/2057-1976/ab6ed1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Mehnati P, Malekzadeh R, Sooteh MY. Use of bismuth shield for protection of superficial radiosensitive organs in patients undergoing computed tomography: a literature review and meta-analysis. Radiol Phys Technol 2019; 12:6-25. [PMID: 30790174 DOI: 10.1007/s12194-019-00500-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 02/03/2019] [Accepted: 02/05/2019] [Indexed: 12/24/2022]
Abstract
The study aimed to assess the effect of bismuth (Bi) shielding on dose reduction and image quality in computed tomography (CT) through a literature review. A search was conducted in the following databases: Web of Science, PubMed, Google Scholar, and Scopus. Studies that reported estimated dose reduction with bismuth shielding during imaging of the eye, thyroid, and breast were included, and a meta-regression analysis was used to examine the influence of the CT scanner type on the dose reduction. The studies included a total of 237 patients and 34 pediatric and adult anthropomorphic phantoms for whom the radiation dose was reported. Bismuth shielding was recommended in 88.89% of the studies based on the maintenance of appropriate image quality under shielding. Noise associated with Bi shielding was 7.5%, 263%, and 23.5% for the eye, thyroid, and breast, respectively. The fixed-effects pooled estimate of dose reduction was 34% (95% CI: 13-55; p < 0.001) for the eye, 37% (95% CI 14-61; p < 0.001) for the thyroid, and 36% (95% CI 36-55; p < 0.001) for the breast. The image quality, usage of foams, CT scanner type, beam energies, and backscatter radiation were important factors that directly affected the efficacy of Bi shielding to reduce the radiation dose at the superficial radiosensitive organs.
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Affiliation(s)
- Parinaz Mehnati
- Medical Radiation Sciences Research Team, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan, Iran
- Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan, Iran
| | - Reza Malekzadeh
- Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan, Iran.
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan, Iran.
| | - Mohammad Yousefi Sooteh
- Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan, Iran
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6
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Protection evaluation of non-lead radiation-shielding fabric: preliminary exposure-dose study. Oral Radiol 2018; 35:224-229. [PMID: 30484195 DOI: 10.1007/s11282-018-0338-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 05/25/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate the effectiveness and shielding performance of a novel recently developed non-lead radiation-shielding fabric containing bismuth oxide (BO-fabric). METHODS BO-fabric was fabricated using urethane resin and bismuth nanopowder. A dose-measurement method was employed to evaluate the radiation-attenuation characteristics of the shielding fabric in accordance with the Korean Standards standard. The shielding performances (%) were calculated by measuring the radiation doses after lamination with increasing layers of fabric (1-10 layers). The physical performance of the fabric in terms of flexural and abrasion resistances was evaluated by the Korea Apparel Testing and Research Institute (KATRI). RESULTS The radiation-attenuation capabilities of one layer of BO-fabric were 58.5, 49.9, and 43.0% at tube voltages of 60, 80, and 100 kVp, respectively. The radiation-shielding performance upon lamination of BO-fabric gradually increased as the number of layers increased. Excellent flexural and abrasion resistances were observed in the KATRI evaluation. CONCLUSIONS A non-lead radiation-shielding fabric based on urethane resin and bismuth was fabricated and examined, revealing an excellent shielding performance. Owing to the flexibility and simple operation of the fabric, it can be employed for various designs of clothing and protective apparel with many purposes.
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Are Bismuth Shields Useful in Dentomaxillofacial Radiology Practice for the Protection of Eyes and Thyroid Glands from Ionizing Radiation? IRANIAN JOURNAL OF RADIOLOGY 2017. [DOI: 10.5812/iranjradiol.40723] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mendes M, Costa F, Figueira C, Madeira P, Teles P, Vaz P. Assessment of patient dose reduction by bismuth shielding in CT using measurements, GEANT4 and MCNPX simulations. RADIATION PROTECTION DOSIMETRY 2015; 165:175-181. [PMID: 25813483 DOI: 10.1093/rpd/ncv059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This work reports on the use of two different Monte Carlo codes (GEANT4 and MCNPX) for assessing the dose reduction using bismuth shields in computer tomography (CT) procedures in order to protect radiosensitive organs such as eye lens, thyroid and breast. Measurements were performed using head and body PMMA phantoms and an ionisation chamber placed in five different positions of the phantom. Simulations were performed to estimate Computed Tomography Dose Index values using GEANT4 and MCNPX. The relative differences between measurements and simulations were <10 %. The dose reduction arising from the use of bismuth shielding ranges from 2 to 45 %, depending on the position of the bismuth shield. The percentage of dose reduction was more significant for the area covered by the bismuth shielding (36 % for eye lens, 39 % for thyroid and 45 % for breast shields).
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Affiliation(s)
- M Mendes
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - F Costa
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - C Figueira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - P Madeira
- Serviço de Radiologia, Hospital de São José, Centro Hospitalar Lisboa Central, EPE, Rua José António Serrano, 1150-199 Lisboa, Portugal
| | - P Teles
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
| | - P Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139,7), 2695-066 Bobadela LRS, Portugal
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Affiliation(s)
- Jie Zhang
- Department of Radiology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536, USA.
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10
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Optimised low-dose multidetector CT protocol for children with cranial deformity. Eur Radiol 2013; 23:2279-87. [DOI: 10.1007/s00330-013-2806-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/11/2013] [Accepted: 01/20/2013] [Indexed: 10/27/2022]
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Qu XM, Li G, Sanderink GCH, Zhang ZY, Ma XC. Dose reduction of cone beam CT scanning for the entire oral and maxillofacial regions with thyroid collars. Dentomaxillofac Radiol 2012; 41:373-8. [PMID: 22707330 DOI: 10.1259/dmfr/30200901] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE The aim of this study was to evaluate the influence of thyroid collars on radiation dose during cone beam CT (CBCT) scanning. METHODS Average tissue-absorbed dose for a NewTom 9000 CBCT scanner (Quantitative Radiology, Verona, Italy) was measured using thermoluminescent dosemeter chips in a phantom. The scans were carried out with and without thyroid collars. Effective organ dose and total effective dose were derived using International Commission on Radiological Protection 2007 recommendations. RESULTS The effective organ doses for the thyroid gland and oesophagus were 31.0 µSv and 2.4 µSv, respectively, during CBCT scanning without a collar around the neck. When the thyroid collars were used loosely around the neck, no effective organ dose reduction was observed. When one thyroid collar was used tightly on the front of the neck, the effective organ dose for the thyroid gland and oesophagus were reduced to 15.9 µSv (48.7% reduction) and 1.4 µSv (41.7% reduction), respectively. Similar organ dose reduction (46.5% and 41.7%) was achieved when CBCT scanning was performed with two collars tightly on the front and back of the neck. However, the differences to the total effective dose were not significant among the scans with and without collars around the neck (p = 0.775). CONCLUSIONS Thyroid collars can effectively reduce the radiation dose to the thyroid and oesophagus if used appropriately.
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Affiliation(s)
- X M Qu
- Department of Oral and Maxillofacial Radiology, Peking University School, Beijing, China
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Rupcich F, Badal A, Kyprianou I, Schmidt TG. A database for estimating organ dose for coronary angiography and brain perfusion CT scans for arbitrary spectra and angular tube current modulation. Med Phys 2012; 39:5336-46. [DOI: 10.1118/1.4739243] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Franco Rupcich
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233
| | - Andreu Badal
- Division of Imaging and Applied Mathematics (OSEL/CDRH), US Food and Drug Administration, Silver Spring, Maryland 20905
| | - Iacovos Kyprianou
- Division of Imaging and Applied Mathematics (OSEL/CDRH), US Food and Drug Administration, Silver Spring, Maryland 20905
| | - Taly Gilat Schmidt
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233
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Kim KP, Berrington de González A, Pearce MS, Salotti JA, Parker L, McHugh K, Craft AW, Lee C. Development of a database of organ doses for paediatric and young adult CT scans in the United Kingdom. RADIATION PROTECTION DOSIMETRY 2012; 150:415-26. [PMID: 22228685 PMCID: PMC3400529 DOI: 10.1093/rpd/ncr429] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 10/17/2011] [Accepted: 10/18/2011] [Indexed: 05/07/2023]
Abstract
Despite great potential benefits, there are concerns about the possible harm from medical imaging including the risk of radiation-related cancer. There are particular concerns about computed tomography (CT) scans in children because both radiation dose and sensitivity to radiation for children are typically higher than for adults undergoing equivalent procedures. As direct empirical data on the cancer risks from CT scans are lacking, the authors are conducting a retrospective cohort study of over 240,000 children in the UK who underwent CT scans. The main objective of the study is to quantify the magnitude of the cancer risk in relation to the radiation dose from CT scans. In this paper, the methods used to estimate typical organ-specific doses delivered by CT scans to children are described. An organ dose database from Monte Carlo radiation transport-based computer simulations using a series of computational human phantoms from newborn to adults for both male and female was established. Organ doses vary with patient size and sex, examination types and CT technical settings. Therefore, information on patient age, sex and examination type from electronic radiology information systems and technical settings obtained from two national surveys in the UK were used to estimate radiation dose. Absorbed doses to the brain, thyroid, breast and red bone marrow were calculated for reference male and female individuals with the ages of newborns, 1, 5, 10, 15 and 20 y for a total of 17 different scan types in the pre- and post-2001 time periods. In general, estimated organ doses were slightly higher for females than males which might be attributed to the smaller body size of the females. The younger children received higher doses in pre-2001 period when adult CT settings were typically used for children. Paediatric-specific adjustments were assumed to be used more frequently after 2001, since then radiation doses to children have often been smaller than those to adults. The database here is the first detailed organ-specific paediatric CT scan database for the UK. As well as forming the basis for the UK study, the results and description of the methods will also serve as a key resource for paediatric CT scan studies currently underway in other countries.
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Affiliation(s)
- K. P. Kim
- Department of Nuclear Engineering, Kyung Hee University, Gyeonggi-do, Republic of Korea
| | - A. Berrington de González
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, MD 20852, USA
| | - M. S. Pearce
- Institute of Health and Society, Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - J. A. Salotti
- Institute of Health and Society, Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - L. Parker
- Departments of Medicine and Pediatrics, Population Cancer Research Program, Dalhousie University, Halifax, NS, Canada
| | - K. McHugh
- Radiology Department, Great Ormond Street Hospital for Children NHS Trust, London, UK
| | - A. W. Craft
- Northern Institute of Cancer Research, Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - C. Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, MD 20852, USA
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Einstein AJ, Elliston CD, Groves DW, Cheng B, Wolff SD, Pearson GDN, Robert Peters M, Johnson LL, Bokhari S, Johnson GW, Bhatia K, Pozniakoff T, Brenner DJ. Effect of bismuth breast shielding on radiation dose and image quality in coronary CT angiography. J Nucl Cardiol 2012; 19:100-8. [PMID: 22068687 PMCID: PMC3266996 DOI: 10.1007/s12350-011-9473-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 10/22/2011] [Indexed: 10/15/2022]
Abstract
BACKGROUND Coronary computed tomographic angiography (CCTA) is associated with high radiation dose to the female breasts. Bismuth breast shielding offers the potential to significantly reduce dose to the breasts and nearby organs, but the magnitude of this reduction and its impact on image quality and radiation dose have not been evaluated. METHODS Radiation doses from CCTA to critical organs were determined using metal-oxide-semiconductor field-effect transistors positioned in a customized anthropomorphic whole-body dosimetry verification phantom. Image noise and signal were measured in regions of interest (ROIs) including the coronary arteries. RESULTS With bismuth shielding, breast radiation dose was reduced 46%-57% depending on breast size and scanning technique, with more moderate dose reduction to the heart, lungs, and esophagus. However, shielding significantly decreased image signal (by 14.6 HU) and contrast (by 28.4 HU), modestly but significantly increased image noise in ROIs in locations of coronary arteries, and decreased contrast-to-noise ratio by 20.9%. CONCLUSIONS While bismuth breast shielding can significantly decrease radiation dose to critical organs, it is associated with an increase in image noise, decrease in contrast-to-noise, and changes tissue attenuation characteristics in the location of the coronary arteries.
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Affiliation(s)
- Andrew J Einstein
- Cardiology Division, Department of Medicine, Columbia University Medical Center/New York-Presbyterian Hospital, 622 West 168th Street PH 10-203A, New York, NY 10032, USA.
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Lee B, Shin G, Kang S, Shin B, Back I, Park H, Park C, Lee J, Lee W, Choi J, Park R, Kim Y. Dose evaluation of selective collimation effect in cephalography by measurement and Monte Carlo simulation. RADIATION PROTECTION DOSIMETRY 2012; 148:58-64. [PMID: 21335329 DOI: 10.1093/rpd/ncq596] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Recently, simulations based on the Monte Carlo code have been increasingly applied for physics phenomena, patient dose and quality assurance of radiation systems. The objective of this study was to use Monte Carlo simulation and measurement to verify dose and dose reduction in cephalography. The collimator was constructed with 3-mm thick lead plate, and attached to the tube head to remove regions of disinterest in the radiation field. A digital phantom patient was constructed to evaluate patient dose. In addition, detectors of pixel size 1×1 cm² and 0.1×0.1 cm² were constructed to check collimator location. The effective dose according to International Commission on Radiological Protection 103 was calculated with and without collimation. The effective doses for simulation with and without collimation were 5.09 and 11.32 µSv, respectively. The results of the calculated effective dose show 61.7 % reduction of field area and 55 % of effective dose. The Monte Carlo simulation is a good evaluation tool for patient dose.
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Affiliation(s)
- Boram Lee
- Department of Radiologic Science, College of Health Science, Korea University, Seoul, Korea
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Lee C, Kim KP, Long D, Fisher R, Tien C, Simon SL, Bouville A, Bolch WE. Organ doses for reference adult male and female undergoing computed tomography estimated by Monte Carlo simulations. Med Phys 2011; 38:1196-206. [PMID: 21520832 DOI: 10.1118/1.3544658] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To develop a computed tomography (CT) organ dose estimation method designed to readily provide organ doses in a reference adult male and female for different scan ranges to investigate the degree to which existing commercial programs can reasonably match organ doses defined in these more anatomically realistic adult hybrid phantoms METHODS The x-ray fan beam in the SOMATOM Sensation 16 multidetector CT scanner was simulated within the Monte Carlo radiation transport code MCNPX2.6. The simulated CT scanner model was validated through comparison with experimentally measured lateral free-in-air dose profiles and computed tomography dose index (CTDI) values. The reference adult male and female hybrid phantoms were coupled with the established CT scanner model following arm removal to simulate clinical head and other body region scans. A set of organ dose matrices were calculated for a series of consecutive axial scans ranging from the top of the head to the bottom of the phantoms with a beam thickness of 10 mm and the tube potentials of 80, 100, and 120 kVp. The organ doses for head, chest, and abdomen/pelvis examinations were calculated based on the organ dose matrices and compared to those obtained from two commercial programs, CT-EXPO and CTDOSIMETRY. Organ dose calculations were repeated for an adult stylized phantom by using the same simulation method used for the adult hybrid phantom. RESULTS Comparisons of both lateral free-in-air dose profiles and CTDI values through experimental measurement with the Monte Carlo simulations showed good agreement to within 9%. Organ doses for head, chest, and abdomen/pelvis scans reported in the commercial programs exceeded those from the Monte Carlo calculations in both the hybrid and stylized phantoms in this study, sometimes by orders of magnitude. CONCLUSIONS The organ dose estimation method and dose matrices established in this study readily provides organ doses for a reference adult male and female for different CT scan ranges and technical parameters. Organ doses from existing commercial programs do not reasonably match organ doses calculated for the hybrid phantoms due to differences in phantom anatomy, as well as differences in organ dose scaling parameters. The organ dose matrices developed in this study will be extended to cover different technical parameters, CT scanner models, and various age groups.
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Affiliation(s)
- Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852, USA.
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