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Belinato W, da Silva Pereira G, Santos WS, Neves LP, Perini AP, Souza DN. Occupational exposures in PET procedures with 18F-FDG in adult and pediatric patients. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Alves MS, Ferro AGL, Moreira MCL, Santos WS, Neves LP, Perini AP, Belinato W, Souza DN. Estimated risk of radiation-induced cancer following breast screening employing tomosynthesis and digital mammography. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:254-265. [PMID: 33498015 DOI: 10.1088/1361-6498/abdfd8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
The objective of this study was to estimate the risk of radiation-induced injury to the organs due to ionizing radiation following breast screening recommendations employing digital breast tomosynthesis (DBT) and digital mammography (DM). Using the Monte Carlo method, absorbed doses in the tissues and organs were calculated on an adult female phantom, considering two-view craniocaudal (CC) and mediolateral oblique (MLO) projections for each breast. The results showed differences in the total effective risk due to DM (CC + MLO) and DBT (CC + MLO) examinations in Brazil, ranging from 20.73 cases 10-5(DM) to 27.19 cases 10-5(DBT). Significant differences were also observed in the total effective risk of cancer incidence in the lungs due to DM (CC + MLO) and DBT (CC + MLO), ranging from 1.75×10-01cases 10-5(DM) to 1.76×10-01cases 10-5(DBT). The results indicate that the total effective risk of incidence should be considered as an additional parameter for the evaluation of DBT or DBT + DM program performance.
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Affiliation(s)
- Marcos S Alves
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
| | - Ana G L Ferro
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
| | - Márcia C L Moreira
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
| | - William S Santos
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Lucio P Neves
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Ana P Perini
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Walmir Belinato
- Instituto Federal da Bahia (IFBA), Vitória da Conquista, BA, Brazil
| | - Divanizia N Souza
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
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Soares MR, Santos WS, Neves LP, Perini AP, Batista WO, Maia AF, Belinato W, Caldas LV. The use of personal protection equipment for the absorbed doses of eye lens and thyroid gland in CBCT exams using Monte Carlo. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2019.108347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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4
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Computational dosimetry in a pediatric i-CAT procedure using virtual anthropomorphic phantoms. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2019.03.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lee C, Badal A, Yeom YS, Griffin K, McMillan D. Dosimetric impact of voxel resolutions of computational human phantoms for external photon exposure. Biomed Phys Eng Express 2019; 5:065002. [PMID: 38500848 PMCID: PMC10948017 DOI: 10.1088/2057-1976/ab2850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Several research teams have developed computational phantoms in polygonal-mesh (PM) and/or Non-Uniform Rational B-Spline format, but it has not been systematically evaluated if the existing voxel phantoms are still dosimetrically valid. We created three voxel phantoms with the resolutions of 1,000, 125, and 1 mm3 and simulated the irradiation in antero-posterior geometry with photons of 0.1, 1, and 10 MeV using voxel Monte Carlo codes, and compared the energy deposition to their organs/tissues with the values from the original PM phantom using mesh Monte Carlo codes. The coefficient of variation in energy deposition overall showed about five-fold decrease as the voxel resolution increased but differences were mostly less than 5% for any voxel resolution. We conclude that PM phantoms and mesh Monte Carlo techniques may not be necessary for external photon exposure (0.1 - 10 MeV) and the existing voxel phantoms can provide enough dosimetric accuracy in those exposure conditions.
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Affiliation(s)
- Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
| | - Andreu Badal
- Division of Imaging, Diagnostics and Software Reliability, OSEL, CDRH, Food and Drug Administration, Silver Spring, MD
| | - Yeon Soo Yeom
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
| | - Keith Griffin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
| | - Dayton McMillan
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD
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Dose estimate for cone beam CT equipment protocols using Monte Carlo simulation in computational adult anthropomorphic phantoms. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2018.06.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Metaxas VI, Messaris GA, Gatzounis GD, Panayiotakis GS. Patient Dose in Fluoroscopically Guided Cervical Discectomy and Fusion. RADIATION PROTECTION DOSIMETRY 2017; 174:575-582. [PMID: 27613745 DOI: 10.1093/rpd/ncw257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 08/10/2016] [Indexed: 06/06/2023]
Abstract
Cervical discectomy and fusion (CDF) is a minimally invasive procedure, where the accurate placement of the implants is accomplished using fluoroscopic guidance. Therefore, the evaluation of the radiation dose becomes mandatory. The purpose of the current study was to assess patient dose during fluoroscopically guided anterior and/or posterior CDF procedures. Thirty-three patients undergoing single or multiple-level CDF were studied using a mobile C-arm system. Data regarding fluoroscopy time (FT), air kerma area product (KAP) and cumulative dose (CD) were recorded. Patient entrance surface dose (ESD), thyroid absorbed dose and effective dose (ED) were calculated from KAP measurements, utilizing the CALDoseX software. The average FT was 0.12 min (range 0.02-0.48 min), resulting to a KAP value of 0.21 Gy cm2 (range 0.01-1.46 Gy cm2) and a CD value of 0.96 mGy (range 0.04-6.58 mGy). The ESD ranged between 0.08 and 13.58 mGy (average 1.95 mGy), the ED between 0.001 and 0.097 mSv (average 0.015 mSv), while the dose absorbed by the thyroid ranged between 0.01 and 1.12 mGy (average 0.194 mGy). The dose associated with the CDF procedure is very low, comparable to that delivered by a lateral X-ray radiograph of the cervical spine. However, higher doses can be revealed, due to the non-optimum use of the X-ray system and extended FTs, mainly affected by complex clinical conditions, as well as the experience of the neurosurgeon. Additional studies need to be conducted for further investigation of the patient dose from the CDF procedure.
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Affiliation(s)
- Vasileios I Metaxas
- Department of Medical Physics, School of Medicine, University of Patras, 265 04 Patras, Greece
| | - Gerasimos A Messaris
- Department of Medical Physics, School of Medicine, University of Patras, 265 04 Patras, Greece
| | - George D Gatzounis
- Department of Neurosurgery, School of Medicine, University of Patras, 265 04 Patras, Greece
| | - George S Panayiotakis
- Department of Medical Physics, School of Medicine, University of Patras, 265 04 Patras, Greece
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Kramer R, Cassola VF, Andrade MEA, de Araújo MWC, Brenner DJ, Khoury HJ. Mathematical modelling of scanner-specific bowtie filters for Monte Carlo CT dosimetry. Phys Med Biol 2017; 62:781-809. [PMID: 28072578 DOI: 10.1088/1361-6560/aa5343] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The purpose of bowtie filters in CT scanners is to homogenize the x-ray intensity measured by the detectors in order to improve the image quality and at the same time to reduce the dose to the patient because of the preferential filtering near the periphery of the fan beam. For CT dosimetry, especially for Monte Carlo calculations of organ and tissue absorbed doses to patients, it is important to take the effect of bowtie filters into account. However, material composition and dimensions of these filters are proprietary. Consequently, a method for bowtie filter simulation independent of access to proprietary data and/or to a specific scanner would be of interest to many researchers involved in CT dosimetry. This study presents such a method based on the weighted computer tomography dose index, CTDIw, defined in two cylindrical PMMA phantoms of 16 cm and 32 cm diameter. With an EGSnrc-based Monte Carlo (MC) code, ratios CTDIw/CTDI100,a were calculated for a specific CT scanner using PMMA bowtie filter models based on sigmoid Boltzmann functions combined with a scanner filter factor (SFF) which is modified during calculations until the calculated MC CTDIw/CTDI100,a matches ratios CTDIw/CTDI100,a, determined by measurements or found in publications for that specific scanner. Once the scanner-specific value for an SFF has been found, the bowtie filter algorithm can be used in any MC code to perform CT dosimetry for that specific scanner. The bowtie filter model proposed here was validated for CTDIw/CTDI100,a considering 11 different CT scanners and for CTDI100,c, CTDI100,p and their ratio considering 4 different CT scanners. Additionally, comparisons were made for lateral dose profiles free in air and using computational anthropomorphic phantoms. CTDIw/CTDI100,a determined with this new method agreed on average within 0.89% (max. 3.4%) and 1.64% (max. 4.5%) with corresponding data published by CTDosimetry (www.impactscan.org) for the CTDI HEAD and BODY phantoms, respectively. Comparison with results calculated using proprietary data for the PHILIPS Brilliance 64 scanner showed agreement on average within 2.5% (max. 5.8%) and with data measured for that scanner within 2.1% (max. 3.7%). Ratios of CTDI100,c/CTDI100, p for this study and corresponding data published by CTDosimetry (www.impactscan.org) agree on average within about 11% (max. 28.6%). Lateral dose profiles calculated with the proposed bowtie filter and with proprietary data agreed within 2% (max. 5.9%), and both calculated data agreed within 5.4% (max. 11.2%) with measured results. Application of the proposed bowtie filter and of the exactly modelled filter to human phantom Monte Carlo calculations show agreement on the average within less than 5% (max. 7.9%) for organ and tissue absorbed doses.
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Affiliation(s)
- R Kramer
- Department of Nuclear Energy, Federal University of Pernambuco, Avenida Prof Luiz Freire, 1000, CEP 50740-540, Recife, Brazil
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Karimi-Shahri K, Rafat-Motavalli L, Miri-Hakimabad H, Liu L, Li J. Effects of computational phantoms on the effective dose and two-dosimeter algorithm for external photon beams. Appl Radiat Isot 2016; 115:155-164. [PMID: 27389880 DOI: 10.1016/j.apradiso.2016.06.019] [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: 11/22/2015] [Revised: 06/10/2016] [Accepted: 06/18/2016] [Indexed: 11/17/2022]
Abstract
In this study, the effect of computational phantoms on the effective dose (E), dosimeter responses positioned on the front (chest) and back of phantom, and two-dosimeter algorithm was investigated for external photon beams. This study was performed using Korean Typical MAN-2 (KTMAN-2), Chinese Reference Adult Male (CRAM), ICRP male reference, and Male Adult meSH (MASH) reference phantoms. Calculations were performed for beam directions in different polar and azimuthal angles using the Monte Carlo code of MCNP at energies of 0.08, 0.3, and 1MeV. Results show that the body shape significantly affects E and two-dosimeter responses when the dosimeters are indirectly irradiated. The acquired two-dosimeter algorithms are almost the same for all the mentioned phantoms except for KTMAN-2. Comparisons between the obtained E and estimated E (Eest), acquired from two-dosimeter algorithm, illustrate that the Eest is overestimated in overhead (OH) and underfoot (UF) directions. The effect of using one algorithm for all phantoms was also investigated. Results show that application of one algorithm to all reference phantoms is possible.
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Affiliation(s)
- K Karimi-Shahri
- Ferdowsi University of Mashhad, Physics Department, School of Sciences, Mashhad, Iran
| | - L Rafat-Motavalli
- Ferdowsi University of Mashhad, Physics Department, School of Sciences, Mashhad, Iran.
| | - H Miri-Hakimabad
- Ferdowsi University of Mashhad, Physics Department, School of Sciences, Mashhad, Iran
| | - L Liu
- China Institute for Radiation Protection, PO 120, Taiyuan 030006, People's Republic of China
| | - J Li
- Department of Engineering Physics, Tsinghua University, 100084 Beijing, People's Republic of China
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Ferreira P, Baptista M, Di Maria S, Vaz P. Cancer risk estimation in Digital Breast Tomosynthesis using GEANT4 Monte Carlo simulations and voxel phantoms. Phys Med 2016; 32:717-23. [PMID: 27133140 DOI: 10.1016/j.ejmp.2016.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Revised: 04/09/2016] [Accepted: 04/13/2016] [Indexed: 10/21/2022] Open
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Geng C, Tang X, Gong C, Guan F, Johns J, Shu D, Chen D. A Monte Carlo-based radiation safety assessment for astronauts in an environment with confined magnetic field shielding. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2015; 35:777-788. [PMID: 26484984 DOI: 10.1088/0952-4746/35/4/777] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The active shielding technique has great potential for radiation protection in space exploration because it has the advantage of a significant mass saving compared with the passive shielding technique. This paper demonstrates a Monte Carlo-based approach to evaluating the shielding effectiveness of the active shielding technique using confined magnetic fields (CMFs). The International Commission on Radiological Protection reference anthropomorphic phantom, as well as the toroidal CMF, was modeled using the Monte Carlo toolkit Geant4. The penetrating primary particle fluence, organ-specific dose equivalent, and male effective dose were calculated for particles in galactic cosmic radiation (GCR) and solar particle events (SPEs). Results show that the SPE protons can be easily shielded against, even almost completely deflected, by the toroidal magnetic field. GCR particles can also be more effectively shielded against by increasing the magnetic field strength. Our results also show that the introduction of a structural Al wall in the CMF did not provide additional shielding for GCR; in fact it can weaken the total shielding effect of the CMF. This study demonstrated the feasibility of accurately determining the radiation field inside the environment and evaluating the organ dose equivalents for astronauts under active shielding using the CMF.
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Affiliation(s)
- Changran Geng
- Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China. Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, People's Republic of China
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Santos WS, Neves LP, Perini AP, Belinato W, Caldas LV, Carvalho AB, Maia AF. Exposures in interventional radiology using Monte Carlo simulation coupled with virtual anthropomorphic phantoms. Phys Med 2015; 31:929-933. [DOI: 10.1016/j.ejmp.2015.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/04/2015] [Accepted: 06/15/2015] [Indexed: 11/26/2022] Open
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Dual-energy contrast-enhanced digital mammography: Glandular dose estimation using a Monte Carlo code and voxel phantom. Phys Med 2015; 31:785-91. [DOI: 10.1016/j.ejmp.2015.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 02/27/2015] [Accepted: 03/22/2015] [Indexed: 11/19/2022] Open
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Garzón WJ, Kramer R, Khoury HJ, de Barros VSM, Andrade G. Estimation of organ doses to patients undergoing hepatic chemoembolization procedures. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2015; 35:629-647. [PMID: 26270613 DOI: 10.1088/0952-4746/35/3/629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The aim of this study is to evaluate organ and tissue absorbed doses to patients undergoing hepatic chemoembolization procedures performed in two hospitals in the city of Recife, Brazil. Forty eight patients undergoing fifty hepatic chemoembolization procedures were investigated. For the 20 cases with PA projection only, organs and tissues dose to KAP conversion coefficients were calculated using the mesh-based anthropometric phantom series FASH and MASH coupled to the EGSnrc Monte Carlo code. Clinical, dosimetric and irradiations parameters were registered for all patients. The maximum organ absorbed doses found were 2.4 Gy, 0.85 Gy, 0.76 Gy and 0.44 Gy for skin, kidneys, adrenals and liver, respectively.
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Affiliation(s)
- W J Garzón
- Department of Nuclear Energy, Federal University of Pernambuco, Recife, Brazil
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Yakoumakis E, Tzamicha E, Dimitriadis A, Georgiou E, Tsapaki V, Chalazonitis A. Dual-energy contrast-enhanced digital mammography: patient radiation dose estimation using a Monte Carlo code. RADIATION PROTECTION DOSIMETRY 2015; 165:369-372. [PMID: 25836682 DOI: 10.1093/rpd/ncv098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Mammography is a standard procedure that facilitates breast cancer detection. Initial results of contrast-enhanced digital mammography (CEDM) are promising. The purpose of this study is to assess the CEDM radiation dose using a Monte Carlo code. EGSnrc MC code was used to simulate the interaction of photons with matter and estimate the glandular dose (Dg). A voxel female human phantom with a 2-8-cm breast thickness range and a breast glandular composition of 50 % was applied. Dg values ranged between 0.96 and 1.45 mGy (low and high energy). Dg values for a breast thickness of 5.0 cm and a glandular fraction of 50 % for craniocaudal and mediolateral oblique view were 1.12 (low energy image contribution is 0.98 mGy) and 1.07 (low energy image contribution is 0.95 mGy), respectively. The low kV part of CEDM is the main contributor to total glandular breast dose.
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Affiliation(s)
- E Yakoumakis
- Medical Physics Department, University of Athens, Athens, Greece
| | - E Tzamicha
- Medical Physics Department, University of Athens, Athens, Greece
| | - A Dimitriadis
- Medical Physics Department, University of Athens, Athens, Greece
| | - E Georgiou
- Medical Physics Department, University of Athens, Athens, Greece
| | - V Tsapaki
- Medical Physics Department, Konstantopoulio General Hospital of Nea Ionia, Attiki, Greece
| | - A Chalazonitis
- Radiology Department, Alexandra General Hospital, Athens, Greece
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Cassola VF, Kramer R, de Melo Lima VJ, de Oliveira Lira CAB, Khoury HJ, Vieira JW, Robson Brown K. Development of newborn and 1-year-old reference phantoms based on polygon mesh surfaces. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2013; 33:669-691. [PMID: 23822973 DOI: 10.1088/0952-4746/33/3/669] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The purpose of this study is the development of paediatric reference phantoms for newborn and 1-year-old infants to be used for the calculation of organ and tissue equivalent doses in radiation protection. The study proposes a method for developing anatomically highly sophisticated paediatric phantoms without using medical images. The newborn and 1-year-old hermaphrodite phantoms presented here were developed using three-dimensional (3D) modelling software applied to anatomical information taken from atlases, textbooks and images provided by the Department of Anatomy of the Federal University of Pernambuco, Brazil. The method uses polygon mesh surfaces to model body contours, the shape of organs as well as their positions and orientations in the human body. Organ and tissue masses agree with corresponding data given by the International Commission on Radiological Protection for newborn and 1-year-old reference children. Bones were segmented into cortical bone, spongiosa, medullary marrow and cartilage to allow for the use of μCT images of trabecular bone for skeletal dosimetry. Anatomical results show 3D images of the phantoms' surfaces, organs and skeletons, as well as tables with organ and tissue masses or skeletal tissue volumes. Dosimetric results present comparisons of organ and tissue absorbed doses or specific absorbed fractions between the newborn and 1-year-old phantoms and corresponding data for other paediatric stylised or voxel phantoms. Most differences were found to be below 10%.
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Affiliation(s)
- V F Cassola
- Department of Nuclear Energy, Federal University of Pernambuco, Avenida Professor Luiz Freire 1000, CEP 50740-540, Recife, Pernambuco, Brazil
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Wu T, Tan L, Shao Q, Li Y, Yang L, Zhao C, Xie Y, Zhang S. Slice-based supine to standing postured deformation for Chinese anatomical models and the dosimetric results by wide band frequency electromagnetic field exposure: morphing. RADIATION PROTECTION DOSIMETRY 2013; 154:26-30. [PMID: 22899214 DOI: 10.1093/rpd/ncs142] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Digital human models are frequently obtained from supine-postured medical images or cadaver slices, but many applications require standing models. This paper presents the work of reconstructing standing Chinese adult anatomical models from supine postured slices. Apart from the previous studies, the deformation works on 2-D segmented slices. The surface profile of the standing posture is adjusted by population measurement data. A non-uniform texture amplification approach is applied on the 2-D slices to recover the skin contour and to redistribute the internal tissues. Internal organ shift due to postures is taken into account. The feet are modified by matrix rotation. Then, the supine and standing models are utilised for the evaluation of electromagnetic field exposure over wide band frequency and different incident directions.
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Affiliation(s)
- Tongning Wu
- China Academy of Telecommunication Research of Ministry of Industry and Information Technology, No.52, Huayuanbei Road, Beijing 100191, China.
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Lima VJDM, Cassola VF, Kramer R, Lira CABDO, Khoury HJ, Vieira JW. Development of 5- and 10-year-old pediatric phantoms based on polygon mesh surfaces. Med Phys 2011; 38:4723-36. [PMID: 21928646 DOI: 10.1118/1.3615623] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The purpose of this study is the development of reference pediatric phantoms for 5- and 10-year-old children to be used for the calculation of organ and tissue equivalent doses in radiation protection. METHODS The study proposes a method for developing anatomically highly sophisticated pediatric phantoms without using medical images. The 5- and 10-year-old male and female phantoms presented here were developed using 3D modeling software applied to anatomical information taken from atlases and textbooks. The method uses polygon mesh surfaces to model body contours, the shape of organs as well as their positions, and orientations in the human body. Organ and tissue masses comply with the corresponding data given by the International Commission on Radiological Protection (ICRP) for the 5- and 10-year-old reference children. Bones were segmented into cortical bone, spongiosa, medullary marrow, and cartilage to allow for the use of micro computer tomographic (microCT) images of trabecular bone for skeletal dosimetry. RESULTS The four phantoms, a male and a female for each age, and their organs are presented in 3D images and their organ and tissue masses in tables which show the compliance of the ICRP reference values. Dosimetric data, calculated for the reference pediatric phantoms by Monte Carlo methods were compared with corresponding data from adult mesh phantoms and pediatric stylized phantoms. The comparisons show reasonable agreement if the anatomical differences between the phantoms are properly taken into account. CONCLUSIONS Pediatric phantoms were developed without using medical images of patients or volunteers for the first time. The models are reference phantoms, suitable for regulatory dosimetry, however, the 3D modeling method can also be applied to medical images to develop patient-specific phantoms.
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Affiliation(s)
- V J de Melo Lima
- Department of Anatomy, Federal University of Pernambuco, Avenida Professor Moraes Rego 1235, CEP 50670-901, Recife, Pernambuco, Brazil
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Cassola VF, Milian FM, Kramer R, de Oliveira Lira CAB, Khoury HJ. Standing adult human phantoms based on 10th, 50th and 90th mass and height percentiles of male and female Caucasian populations. Phys Med Biol 2011; 56:3749-72. [PMID: 21628776 DOI: 10.1088/0031-9155/56/13/002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Computational anthropomorphic human phantoms are useful tools developed for the calculation of absorbed or equivalent dose to radiosensitive organs and tissues of the human body. The problem is, however, that, strictly speaking, the results can be applied only to a person who has the same anatomy as the phantom, while for a person with different body mass and/or standing height the data could be wrong. In order to improve this situation for many areas in radiological protection, this study developed 18 anthropometric standing adult human phantoms, nine models per gender, as a function of the 10th, 50th and 90th mass and height percentiles of Caucasian populations. The anthropometric target parameters for body mass, standing height and other body measures were extracted from PeopleSize, a well-known software package used in the area of ergonomics. The phantoms were developed based on the assumption of a constant body-mass index for a given mass percentile and for different heights. For a given height, increase or decrease of body mass was considered to reflect mainly the change of subcutaneous adipose tissue mass, i.e. that organ masses were not changed. Organ mass scaling as a function of height was based on information extracted from autopsy data. The methods used here were compared with those used in other studies, anatomically as well as dosimetrically. For external exposure, the results show that equivalent dose decreases with increasing body mass for organs and tissues located below the subcutaneous adipose tissue layer, such as liver, colon, stomach, etc, while for organs located at the surface, such as breasts, testes and skin, the equivalent dose increases or remains constant with increasing body mass due to weak attenuation and more scatter radiation caused by the increasing adipose tissue mass. Changes of standing height have little influence on the equivalent dose to organs and tissues from external exposure. Specific absorbed fractions (SAFs) have also been calculated with the 18 anthropometric phantoms. The results show that SAFs decrease with increasing height and increase with increasing body mass. The calculated data suggest that changes of the body mass may have a significant effect on equivalent doses, primarily for external exposure to organs and tissue located below the adipose tissue layer, while for superficial organs, for changes of height and for internal exposures the effects on equivalent dose are small to moderate.
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Affiliation(s)
- V F Cassola
- Department of Nuclear Energy, Federal University of Pernambuco, Avenida Professor Luiz Freire, 1000, CEP 50740-540, Recife, PE, Brazil
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