1
|
Validation and comparison of radiograph-based organ dose reconstruction approaches for Wilms’ tumor radiation treatment plans. Adv Radiat Oncol 2022; 7:101015. [PMID: 36060631 PMCID: PMC9429523 DOI: 10.1016/j.adro.2022.101015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 06/22/2022] [Indexed: 11/22/2022] Open
|
2
|
Wang Q, Fu Q, Pang C. A NEW METHOD FOR ESTIMATING INCREASE IN RADIATION DOSE ASSOCIATED WITH IODINATED CONTRAST USE. RADIATION PROTECTION DOSIMETRY 2022; 198:281-289. [PMID: 35368083 DOI: 10.1093/rpd/ncac026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 01/25/2022] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
This work investigates the impact of iodinated contrast medium (ICM) on radiation dose in computed tomography (CT) scans using linear models established through a phantom study. Thermoluminescence dosemeters (TLDs) were calibrated using semi-conductor X-ray dosemeters. An electron density phantom, with a vial containing TLDs and different concentrations of iodinated blood, were scanned at different tube voltages. Irradiated TLD outputs were measured and absorbed dose to iodinated blood calculated. CT numbers (tissue attenuation as measured by Hounsfield units) were plotted against absorbed doses to obtain linear models. Data from 49 real patient scans were used to validate the linear models. At each X-ray energy, CT numbers were linearly correlated with the absorbed doses, that is with the increase of blood iodine concentration, the CT number increased and the absorbed dose increased accordingly. ICM can cause an increase of organ dose; the average dose increases were 31.8 ± 8.9% for thyroid, 37.1 ± 9.2% for cardiac muscle, 77.7 ± 14.0% for cardiac chamber, 7.1 ± 2.3% for breast, 26.1 ± 7.3% for liver, 39.8 ± 11.8% for spleen, 96.3 ± 12.2% for renal cortex and 82.4 ± 11.6% for medulla nephrica. ICM used in enhanced CT scan resulted in increased organ doses. Our models for estimating organ dose based on CT number were established by experiment and verified in clinical use.
Collapse
Affiliation(s)
- Qiang Wang
- Department of Occupational Disease Prevention, Changzhou Center for Disease Control and Prevention, Changzhou, Jiangsu 213022, China
| | - Qiang Fu
- Department of Occupational Disease Prevention, Changzhou Center for Disease Control and Prevention, Changzhou, Jiangsu 213022, China
| | - Cong Pang
- The First People's Hospital of Changzhou, Changzhou, Jiangsu 213022, China
| |
Collapse
|
3
|
GATE/GEANT4 simulation of radiation risk induced cancer from mammographic screening. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2021.109929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
4
|
Park M, Kim HS, Yoo J, Kim CH, Jang WI, Park S. Virtual calibration of whole-body counters to consider the size dependency of counting efficiency using Monte Carlo simulations. NUCLEAR ENGINEERING AND TECHNOLOGY 2021. [DOI: 10.1016/j.net.2021.06.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
5
|
Alves MS, Belinato W, Santos WS, Galeano DC, Neves LP, Perini AP, N Souza D. Dosimetry in Digital Breast Tomosynthesis Evaluated by Monte Carlo Technique. HEALTH PHYSICS 2021; 121:18-29. [PMID: 33867436 DOI: 10.1097/hp.0000000000001407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
ABSTRACT The influence of the angular deviation of the tube during digital breast tomosynthesis (DBT) acquisition to the dose in the examined breast and in other organs and tissues is not well known. In this work, the Monte Carlo method was used with an adult female virtual anthropomorphic phantom to investigate the impact of this angular variation on the breast dose. The absorbed dose in the examined breast was normalized by the air kerma, which resulted in an absorbed dose coefficient (DT/Kair) for the breast. The absorbed dose in each organ was normalized by the glandular dose in the breast, resulting in the relative organ dose (ROD). An adult female virtual anthropomorphic phantom (FSTA_M50_H50) was incorporated into a scenario containing tomosynthesis equipment with Mo/Mo, Mo/Rh, and W/Rh target/filter combinations and tube voltages of 28 kV. The comparison between the results of the simulations considering digital mammography (DM) and DBT data showed that the DT/Kair values for the examined breast obtained with the DBT parameters were up to 24 times higher than with the DT/Kair obtained with DM parameters. A DT/Kair of 0.97 × 10-1 mGy mGy-1 was obtained in a DBT exam of the right breast. Considering the other organs, the highest ROD values were observed in the thyroid (6.45 × 10-4), eyes (3.87 × 10-4), liver (1.95 × 10-5), and eye lenses (3.21 × 10-3). A variation in the absorbed dose values for the breast and other organs was observed for all projections different from 0°.
Collapse
Affiliation(s)
- Marcos S Alves
- Departamento de Física, Universidade Federal de Sergipe (UFS), São Cristóvão, Sergipe, Brazil
| | - Walmir Belinato
- Instituto Federal da Bahia (IFBA), Vitória da Conquista, BA, Brazil
| | - William S Santos
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Diego C Galeano
- Hospital Universitário Júlio Müller, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | | | | | - Divanizia N Souza
- Departamento de Física, Universidade Federal de Sergipe (UFS), São Cristóvão, Sergipe, Brazil
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Souza SP, Silva MF, Tavares OJ, Souza LWG, Silva DC, Santos WS, Belinato W, Perini AP, Neves LP. Monte Carlo evaluation of occupational exposure during uterine artery embolization. Phys Med 2021; 85:50-56. [PMID: 33965741 DOI: 10.1016/j.ejmp.2021.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/22/2021] [Accepted: 04/24/2021] [Indexed: 10/21/2022] Open
Abstract
PURPOSE Uterine fibroids affect women mainly of childbearing age, an alternative for the treatment of these fibroids is uterine artery embolization (UAE), a minimally invasive procedure which uses fluoroscopy, providing radiation doses often high, due to the fact that professionals remain in the room throughout the procedure. In this work, equivalent and effective doses were evaluated for the main physician, for the assistant and for the patient during the UAE procedure. METHODS Doses were calculated using computer simulation with the Monte Carlo Method, and virtual anthropomorphic phantoms, in a typical scenario of interventional radiology with field sizes of 20 × 20, 25 × 25 and 32 × 32 cm2, tube voltages of 70, 80, 90 and 100 kV, and projections of LAO45, RAO45 and PA. RESULTS The results showed that the highest doses received by the professionals were for the LAO45 projection with 32 × 32 cm2 field size and 100 kV tube voltage, which is in accordance with the existing literature. The highest equivalent doses, without the protective equipment, were in the eyes, skin, breast and stomach for the main physician, and for the assistant they were in the eyes, breast, thyroid and skin. When she used the protective equipment, the highest equivalent doses for the main physician were on the skin, brain, bone marrow and bone surface, and for the assistant they were on the skin, brain, red bone marrow and bone surface. CONCLUSIONS Effective doses increased up to 3186% for the main physician, and 2462% for the assistant, without protective equipment, thus showing their importance.
Collapse
Affiliation(s)
- Samara P Souza
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, MG, Brazil
| | - Monique F Silva
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, MG, Brazil
| | - Otávio J Tavares
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, MG, Brazil
| | - Lucas W G Souza
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, MG, Brazil; Instituto Maria Ranulfa Ltda, FATRA - Faculdade do Trabalho, Av. Paes Leme Osvaldo, 38408000 Uberlândia, MG, Brazil
| | - Daniela C Silva
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, MG, Brazil
| | - William S Santos
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Walmir Belinato
- Instituto Federal da Bahia (IFBA), Vitória da Conquista, BA, Brazil
| | - Ana P Perini
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, MG, Brazil; Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Lucio P Neves
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, MG, Brazil; Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
| |
Collapse
|
8
|
Santos WS, Souza LW, Neves LP, Perini AP, Santos CJ, Belinato W, Caldas LV. Evaluation of fetal, medical and occupational exposure in ERCP procedures using Monte Carlo simulation and virtual anthropomorphic phantoms. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.109113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
9
|
Kim CH, Yeom YS, Petoussi-Henss N, Zankl M, Bolch WE, Lee C, Choi C, Nguyen TT, Eckerman K, Kim HS, Han MC, Qiu R, Chung BS, Han H, Shin B. ICRP Publication 145: Adult Mesh-Type Reference Computational Phantoms. Ann ICRP 2020; 49:13-201. [PMID: 33231095 DOI: 10.1177/0146645319893605] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
|
10
|
Choi C, Yeom YS, Lee H, Han H, Shin B, Nguyen TT, Kim CH. Body-size-dependent phantom library constructed from ICRP mesh-type reference computational phantoms. Phys Med Biol 2020; 65:125014. [PMID: 32344386 DOI: 10.1088/1361-6560/ab8ddc] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recently, ICRP Task Group 103 developed new mesh-type reference computational phantoms (MRCPs) for the adult male and female by converting the current voxel-type reference computational phantoms (VRCPs) of ICRP Publication 110 into a high-quality/fidelity mesh format. Utilizing the great deformability/flexibility of the MRCPs compared with the VRCPs, in the present study, we established a body-size-dependent phantom library by modifying the MRCPs. The established library includes 108 adult male and 104 adult female phantoms in different standing heights and body weights, covering most body sizes representative of Caucasian and Asian populations. Ten secondary anthropometric parameters with respect to standing height and body weight were derived from various anthropometric databases and applied in the construction of the phantom library. An in-house program for automatic phantom adjustment was developed and applied for practical construction of such a large number of phantoms in the library with minimized human intervention. Organ/tissue doses calculated with three male phantoms in different standing heights (165, 175, and 190 cm) with a fixed body weight of 80 kg for external exposures to broad parallel photon beams from 0.01 to 104 MeV were compared, observing there are significant dose differences particularly for the photon energies <0.1 MeV in which the organ/tissue doses tended to increase with increasing standing height. In addition, the organ/tissue doses of three female phantoms in different body weights (45, 65, and 140 kg) with a fixed standing height of 165 cm were compared, showing a significant decreasing tendency with increasing body weight for the photon energies <10 MeV. For the higher energies, the opposite trend, interestingly, was observed; that is, the organ/tissue doses tended to increase with increasing body weight. The results, despite the limited number of exposure cases, suggest that the use of the body-size-dependent phantom library can improve the accuracy of individual dose estimates for many retrospective dosimetry studies by taking the body size of individuals into account.
Collapse
Affiliation(s)
- Chansoo Choi
- Department of Nuclear Engineering, Hanyang University, Seoul, Republic of Korea
| | | | | | | | | | | | | |
Collapse
|
11
|
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]
|
12
|
|
13
|
Ebrahimi-Khankook A, Akhlaghi P, Vejdani-Noghreiyan A. Studying the lung dose uncertainty during chest CT scans using phantoms with statistical lung volumes and shapes. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2019; 39:443-454. [PMID: 30673649 DOI: 10.1088/1361-6498/ab0116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In recent years, there has been increasing interest in constructing a series of deformable phantoms which follow the statistical distributions of some anatomical variations, known as 'statistical phantoms'. The main purpose of this study was to develop statistical phantoms by considering the variations in lung volume and shape, in order to evaluate the lung dose uncertainty for individuals undergoing chest computed tomography. Calculations were performed for 100 statistical lung volume phantoms and 70 statistical lung shape phantoms at tube voltages of 80 and 120 kVp, with the use of Monte Carlo MCNP code. The obtained results indicate that dose fluctuations for low tube voltage (80 kVp) are higher than those at 120 kVp. Moreover, it shows that the impact of statistical variations in lung volume on dose discrepancy (5% to 7%) is higher than the impact of statistical lung shape variations (around 2%).
Collapse
|
14
|
Abadi E, Harrawood B, Sharma S, Kapadia A, Segars WP, Samei E. DukeSim: A Realistic, Rapid, and Scanner-Specific Simulation Framework in Computed Tomography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2019; 38:1457-1465. [PMID: 30561344 PMCID: PMC6598436 DOI: 10.1109/tmi.2018.2886530] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The purpose of this study was to develop a CT simulation platform that is: 1) compatible with voxel-based computational phantoms; 2) capable of modeling the geometry and physics of commercial CT scanners; and 3) computationally efficient. Such a simulation platform is designed to enable the virtual evaluation and optimization of CT protocols and parameters for achieving a targeted image quality while reducing radiation dose. Given a voxelized computational phantom and a parameter file describing the desired scanner and protocol, the developed platform DukeSim calculates projection images using a combination of ray-tracing and Monte Carlo techniques. DukeSim includes detailed models for the detector quantum efficiency, quantum and electronic noise, detector crosstalk, subsampling of the detector and focal spot areas, focal spot wobbling, and the bowtie filter. DukeSim was accelerated using GPU computing. The platform was validated using physical and computational versions of a phantom (Mercury phantom). Clinical and simulated CT scans of the phantom were acquired at multiple dose levels using a commercial CT scanner (Somatom Definition Flash; Siemens Healthcare). The real and simulated images were compared in terms of image contrast, noise magnitude, noise texture, and spatial resolution. The relative error between the clinical and simulated images was less than 1.4%, 0.5%, 2.6%, and 3%, for image contrast, noise magnitude, noise texture, and spatial resolution, respectively, demonstrating the high realism of DukeSim. The runtime, dependent on the imaging task and the hardware, was approximately 2-3 minutes per rotation in our study using a computer with 4 GPUs. DukeSim, when combined with realistic human phantoms, provides the necessary toolset with which to perform large-scale and realistic virtual clinical trials in a patient and scanner-specific manner.
Collapse
|
15
|
Wang Z, Balgobind BV, Virgolin M, van Dijk IWEM, Wiersma J, Ronckers CM, Bosman PAN, Bel A, Alderliesten T. How do patient characteristics and anatomical features correlate to accuracy of organ dose reconstruction for Wilms' tumor radiation treatment plans when using a surrogate patient's CT scan? JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2019; 39:598-619. [PMID: 30965301 DOI: 10.1088/1361-6498/ab1796] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In retrospective radiation treatment (RT) dosimetry, a surrogate anatomy is often used for patients without 3D CT. To gain insight in what the crucial aspects in a surrogate anatomy are to enable accurate dose reconstruction, we investigated the relation of patient characteristics and internal anatomical features with deviations in reconstructed organ dose using surrogate patient's CT scans. Abdominal CT scans of 35 childhood cancer patients (age: 2.1-5.6 yr; 17 boys, 18 girls) undergoing RT during 2004-2016 were included. Based on whether an intact right or left kidney is present in the CT scan, two groups were formed each containing 24 patients. From each group, four CTs associated with Wilms' tumor RT plans with an anterior-posterior-posterior-anterior field setup were selected as references. For each reference, a 2D digitally reconstructed radiograph was computed from the reference CT to simulate a 2D radiographic image and dose reconstruction was performed on the other CTs in the respective group. Deviations in organ mean dose (DEmean) of the reconstructions versus the references were calculated, as were deviations in patient characteristics (i.e. age, height, weight) and in anatomical features including organ volume, location (in 3D), and spatial overlaps. Per reference, the Pearson's correlation coefficient between deviations in DEmean and patient characteristics/features were studied. Deviation in organ locations and DEmean for the liver, spleen, and right kidney were moderately correlated (R2 > 0.5) for 8/8, 5/8, and 3/4 reference plans, respectively. Deviations in organ volume or spatial overlap and DEmean for the right and left kidney were weakly correlated (0.3 < R2 < 0.5) in 4/4 and 1/4 reference plans. No correlations (R2 < 0.3) were found between deviations in age or height and DEmean. Therefore, the performance of organ dose reconstruction using surrogate patients' CT scans is primarily related to deviation in organ location, followed by volume and spatial overlap. Further, results were plan dependent.
Collapse
Affiliation(s)
- Ziyuan Wang
- Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Pereira MAM, Silveira LM, Nannini F, Neves LP, Perini AP, Santos CJ, Belinato W, Santos WS. Dosimetric evaluation of individuals to 238U series, 232Th series and 40K radionuclides present in Brazilian ornamental rocks using computational simulation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 173:401-410. [PMID: 30798183 DOI: 10.1016/j.ecoenv.2019.02.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 02/09/2019] [Accepted: 02/12/2019] [Indexed: 06/09/2023]
Abstract
Granites are widely used in construction and they may be potential sources of ionizing radiation, due to the presence of radionuclides such as 40Kand decay products from 238Useries and 232Thseries. These radionuclides occur in the minerals constituting the rocks. To evaluate the doses in humans exposed to 40K, and decay products from 238Useries and 232Thseries γ radiation, a room with dimensions of 4.0 × 5.0 × 2.8 m3, with uniformly distributed radiation source on the floor of granitic rocks, was computationally modeled. Adult individuals were represented in the virtual scenario by two virtual anthropomorphic phantoms FASH3 and MASH3, incorporated simultaneously in the software MCNPX 2.7.0. The mean energy deposited on each organ and tissue of FASH3 and MASH3 phantoms was determined using the MCNPX F6 tally (MeV/g/particle), while the photon flux within the room was calculated with the MCNPX F4 tally (MeV/cm2/particle). The organs that obtained the highest conversion coefficients CC[HT](Sv/Gy) were the red bone marrow (0.94), skin (0.90), breast (0.81) and bladder (0.73) for the FASH3; skin (0.89), gonads (0.88), breast (0.79) and bladder (0.70) for the MASH3. The simulated air absorbed dose rates varied between 23.4 (11%) and 25.8 (12%) nGy/h, and the annual dose rates were 0.10 (6%) and 0.11 (6%) mSv/year. These results presented acceptable statistical uncertainties and they are in agreement with the literature. Fluency of photons pointed to the central region of the room floor as the place of greatest exposure. The results showed that the organs closer to the radiation source had the highest deposited energy values. Based on the annual effective dose data obtained, it was possible to note that the values are within the literature. We believe that the methodology used will allow the investigation of any ornamental material that emits natural radiation.
Collapse
Affiliation(s)
- Marco A M Pereira
- Instituto de Geografia, Universidade Federal de Uberlândia, Monte Carmelo, MG, Brazil.
| | - Lucas M Silveira
- Instituto de Geografia, Universidade Federal de Uberlândia, Monte Carmelo, MG, Brazil.
| | - Felix Nannini
- Instituto de Geografia, Universidade Federal de Uberlândia, Monte Carmelo, 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.
| | - Carla J Santos
- 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), Departamento de ensino, Vitória da Conquista, BA, Brazil.
| | - William S Santos
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil; Instituto de Pesquisas Energéticas e Nucleares, Comissão Nacional de Energia Nuclear (IPEN-CNEN/SP), São Paulo, SP, Brazil.
| |
Collapse
|
17
|
George Xu X. Innovations in Computer Technologies Have Impacted Radiation Dosimetry Through Anatomically Realistic Phantoms and Fast Monte Carlo Simulations. HEALTH PHYSICS 2019; 116:263-275. [PMID: 30585974 DOI: 10.1097/hp.0000000000001007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Radiological physics principles have not changed in the past 60 y when computer technologies advanced exponentially. The research field of anatomical modeling for the purpose of radiation dose calculations has experienced an explosion in activity in the past two decades. Such an exciting advancement is due to the feasibility of creating three-dimensional geometric details of the human anatomy from tomographic imaging and of performing Monte Carlo radiation transport simulations on increasingly fast and cheap personal computers. The advent of a new type of high-performance computing hardware in recent years-graphics processing units-has made it feasible to carry out time-consuming Monte Carlo calculations at near real-time speeds. This paper introduces the history of three generations of computational human phantoms (the stylized medical internal radiation dosimetry-type phantoms, the voxelized tomographic phantoms, and the boundary representation deformable phantoms) and new development of the graphics processing unit-based Monte Carlo radiation dose calculations. Examples are given for research projects performed by my students in applying computational phantoms and a new Monte Carlo code, ARCHER, to problems in radiation protection, imaging, and radiotherapy. Finally, the paper discusses challenges and future opportunities for research.
Collapse
Affiliation(s)
- X George Xu
- JEC 5049, Rensselaer Polytechnic Institute, 110 8th St., Troy, NY 12180
| |
Collapse
|
18
|
Akhavanallaf A, Xie T, Zaidi H. Development of a Library of Adult Computational Phantoms Based on Anthropometric Indexes. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019. [DOI: 10.1109/trpms.2018.2816072] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
19
|
Belinato W, Silva RM, Perini AP, Neves LP, Santos CJ, Souza DN, Santos WS. Monte Carlo dosimetric evaluation in PET exams for patients with different BMI and heights. Radiat Phys Chem Oxf Engl 1993 2018. [DOI: 10.1016/j.radphyschem.2018.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
20
|
Wang H, Sun X, Wu T, Li C, Chen Z, Liao M, Li M, Yan W, Huang H, Yang J, Tan Z, Hui L, Liu Y, Pan H, Qu Y, Chen Z, Tan L, Yu L, Shi H, Huo L, Zhang Y, Tang X, Zhang S, Liu C. Deformable torso phantoms of Chinese adults for personalized anatomy modelling. J Anat 2018; 233:121-134. [PMID: 29663370 PMCID: PMC5987821 DOI: 10.1111/joa.12815] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2018] [Indexed: 11/26/2022] Open
Abstract
In recent years, there has been increasing demand for personalized anatomy modelling for medical and industrial applications, such as ergonomics device development, clinical radiological exposure simulation, biomechanics analysis, and 3D animation character design. In this study, we constructed deformable torso phantoms that can be deformed to match the personal anatomy of Chinese male and female adults. The phantoms were created based on a training set of 79 trunk computed tomography (CT) images (41 males and 38 females) from normal Chinese subjects. Major torso organs were segmented from the CT images, and the statistical shape model (SSM) approach was used to learn the inter-subject anatomical variations. To match the personal anatomy, the phantoms were registered to individual body surface scans or medical images using the active shape model method. The constructed SSM demonstrated anatomical variations in body height, fat quantity, respiratory status, organ geometry, male muscle size, and female breast size. The masses of the deformed phantom organs were consistent with Chinese population organ mass ranges. To validate the performance of personal anatomy modelling, the phantoms were registered to the body surface scan and CT images. The registration accuracy measured from 22 test CT images showed a median Dice coefficient over 0.85, a median volume recovery coefficient (RCvlm ) between 0.85 and 1.1, and a median averaged surface distance (ASD) < 1.5 mm. We hope these phantoms can serve as computational tools for personalized anatomy modelling for the research community.
Collapse
Affiliation(s)
- Hongkai Wang
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Xiaobang Sun
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
- Department of Information TechnologyUniversity of JyväskyläJyväskyläFinland
| | - Tongning Wu
- China Academy of Industry and Communications TechnologyBeijingChina
| | - Congsheng Li
- China Academy of Industry and Communications TechnologyBeijingChina
| | - Zhonghua Chen
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Meiying Liao
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Mengci Li
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Wen Yan
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Hui Huang
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Jia Yang
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Ziyu Tan
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Libo Hui
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Yue Liu
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Hang Pan
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Yue Qu
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Zhaofeng Chen
- Department of Biomedical EngineeringFaculty of Electronic Information and Electrical EngineeringDalian University of TechnologyDalianLiaoningChina
| | - Liwen Tan
- Institute of Digital MedicineThird Military Medical UniversityChongqingChina
| | - Lijuan Yu
- The Affiliated Cancer Hospital of Hainan Medical CollegeHaikouHainanChina
| | - Hongcheng Shi
- Department of Nuclear MedicineZhongshan HospitalFudan UniversityShanghaiChina
| | - Li Huo
- Department of Nuclear MedicinePeking Union Medical College HospitalBeijingChina
| | - Yanjun Zhang
- Department of Nuclear Medicinethe First Affiliated Hospital of Dalian Medical UniversityDalianLiaoningChina
| | - Xin Tang
- Trauma Department of Orthopaedicsthe First Affiliated Hospital of Dalian Medical UniversityDalianLiaoningChina
| | - Shaoxiang Zhang
- Institute of Digital MedicineThird Military Medical UniversityChongqingChina
| | - Changjian Liu
- Trauma Department of Orthopaedicsthe First Affiliated Hospital of Dalian Medical UniversityDalianLiaoningChina
| |
Collapse
|
21
|
Abadi E, Segars WP, Sturgeon GM, Harrawood B, Kapadia A, Samei E. Modeling "Textured" Bones in Virtual Human Phantoms. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018; 3:47-53. [PMID: 31559375 DOI: 10.1109/trpms.2018.2828083] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The purpose of this study was to develop detailed and realistic models of the cortical and trabecular bones in the spine, ribs, and sternum and incorporate them into the library of virtual human phantoms (XCAT). Cortical bone was modeled by 3D morphological erosion of XCAT homogenously defined bones with an average thickness measured from the CT dataset upon which each individual XCAT phantom was based. The trabecular texture was modeled using a power law synthesis algorithm where the parameters were tuned using high-resolution anatomical images of the Human Visible Female. The synthesized bone textures were added into the XCAT phantoms. To qualitatively evaluate the improved realism of the bone modeling, CT simulations of the XCAT phantoms were acquired with and without the textured bone modeling. The 3D power spectrum of the anatomical images exhibited a power law behavior (R2 = 0.84), as expected in fractal and porous textures. The proposed texture synthesis algorithm was able to synthesize textures emulating real anatomical images, with the simulated CT images with the prototyped bones were more realistic than those simulated with the original XCAT models. Incorporating intra-organ structures, the "textured" phantoms are envisioned to be used to conduct virtual clinical trials in the context of medical imaging in cases where the actual trials are infeasible due to the lack of ground truth, cost, or potential risks to the patients.
Collapse
Affiliation(s)
- Ehsan Abadi
- Department of Electrical and Computer Engineering, and the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University, Durham, NC, 27705 USA
| | - William P Segars
- Carl E. Ravin Advanced Imaging Laboratories, the Department of Radiology, the Medical Physics Graduate Program, and the Department of Biomedical Engineering, Duke University, Durham, NC, 27705 USA
| | - Gregory M Sturgeon
- Carl E. Ravin Advanced Imaging Laboratories and the Department of Radiology, Duke University Medical Center, Durham, NC, 27705 USA
| | - Brian Harrawood
- Carl E. Ravin Advanced Imaging Laboratories and Department of Radiology, Duke University Medical Center, Durham, NC, 27705 USA
| | - Anuj Kapadia
- Carl E. Ravin Advanced Imaging Laboratories, the Department of Radiology, and the Medical Physics Graduate Program, Durham, NC, 27705 USA
| | - Ehsan Samei
- Carl E. Ravin Advanced Imaging Laboratories, the Department of Electrical and Computer Engineering, the Department of Radiology, the Department of Biomedical Engineering, the Medical Physics Graduate Program, and the Department of Physics, Duke University, Durham, NC, 27705 USA
| |
Collapse
|
22
|
Wang Z, van Dijk IWEM, Wiersma J, Ronckers CM, Oldenburger F, Balgobind BV, Bosman PAN, Bel A, Alderliesten T. Are age and gender suitable matching criteria in organ dose reconstruction using surrogate childhood cancer patients' CT scans? Med Phys 2018; 45:2628-2638. [PMID: 29637577 DOI: 10.1002/mp.12908] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 03/19/2018] [Accepted: 03/27/2018] [Indexed: 12/25/2022] Open
Abstract
PURPOSE The purpose of this work was to assess the feasibility of using surrogate CT scans of matched patients for organ dose reconstructions for childhood cancer (CC) survivors, treated in the past with only 2D imaging data available instead of 3D CT data, and in particular using the current literature standard of matching patients based on similarity in age and gender. METHODS Thirty-one recently treated CC patients with abdominal CT scans were divided into six age- and gender-matched groups. From each group, two radiotherapy plans for Wilms' tumor were selected as reference plans and applied to the age- and gender-matched patients' CTs in the respective group. Two reconstruction strategies were investigated: S1) without field adjustments; S2) with manual field adjustments according to anatomical information, using a visual check in digitally reconstructed radiographs. To assess the level of agreement between the reconstructed and the reference dose distributions, we computed (using a collapsed cone algorithm) and compared the absolute deviation in mean and maximum dose normalized by the prescribed dose (i.e., normalized errors |NEmean | and |NE2cc |) in eight organs at risk (OARs): heart, lungs, liver, spleen, kidneys, and spinal cord. Furthermore, we assessed the quality of a reconstruction case by varying acceptance thresholds for |NEmean | and |NE2cc |. A reconstruction case was accepted (i.e., considered to pass) if the errors in all OARs are smaller than the threshold. The pass fraction for a given threshold was then defined as the percentage of reconstruction cases that were classified as a pass. Furthermore, we consider the impact of allowing to use a different CT scan for each OAR. RESULTS Slightly smaller reconstruction errors were achieved with S2 in multiple OARs than with S1 (P < 0.05). Among OARs, the best reconstruction was found for the spinal cord (average |NEmean | and |NE2cc | ≤ 4%). The largest average |NEmean | was found in the spleen (18%). The largest average |NE2cc | was found in the left lung (26%). Less than 30% of the reconstruction cases (i.e., pass fraction) meet the criteria that |NEmean | < 20% and |NE2cc | < 20% in all OARs when using age and gender matching and a single CT to do reconstructions. Allowing other matchings and combining reconstructions for OARs from multiple patients, the pass fraction increases substantially to more than 60%. CONCLUSIONS To conclude, reconstructions with small deviations can be obtained by using CC patients' CT scans, making the general approach promising. However, using age and gender as the only matching criteria to select a CT scan for the reconstruction is not sufficient to guarantee sufficiently low reconstruction errors. It is therefore suggested to include more features (e.g., height, features extracted from 2D radiographs) than only age and gender for dose reconstruction for CC survivors treated in the pre-3D radiotherapy planning era and to consider ways to combine multiple reconstructions focused on different OARs.
Collapse
Affiliation(s)
- Ziyuan Wang
- Department of Radiation Oncology, Academic Medical Center (AMC), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Irma W E M van Dijk
- Department of Radiation Oncology, Academic Medical Center (AMC), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Jan Wiersma
- Department of Radiation Oncology, Academic Medical Center (AMC), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Cécile M Ronckers
- Department of Pediatric Oncology, Emma Children's Hospital/AMC, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Foppe Oldenburger
- Department of Radiation Oncology, Academic Medical Center (AMC), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Brian V Balgobind
- Department of Radiation Oncology, Academic Medical Center (AMC), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Peter A N Bosman
- Centrum Wiskunde & Informatica (CWI), Science Park 123, 1098 XG, Amsterdam, The Netherlands
| | - Arjan Bel
- Department of Radiation Oncology, Academic Medical Center (AMC), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Tanja Alderliesten
- Department of Radiation Oncology, Academic Medical Center (AMC), Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| |
Collapse
|
23
|
Occupational exposures during abdominal fluoroscopically guided interventional procedures for different patient sizes — A Monte Carlo approach. Phys Med 2018; 45:35-43. [DOI: 10.1016/j.ejmp.2017.11.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/21/2017] [Accepted: 11/24/2017] [Indexed: 01/22/2023] Open
|
24
|
Monte Carlo calculation of the neutron dose to a fetus at commercial flight altitudes. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.03.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
25
|
Liu C, Liang X. Calculation of the Photon Dose Conversion Coefficient Based on Boundary Representation Phantoms of Different Postures. HEALTH PHYSICS 2017; 113:353-362. [PMID: 28961583 DOI: 10.1097/hp.0000000000000712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Based on the hybrid Chinese reference adult female phantom, the Chinese reference female boundary representation (BREP) phantoms involving sitting, walking, and squatting postures were established. The photon effective dose conversion coefficient (ECCK) and some organ absorbed dose conversion coefficients (DCCK) were calculated under six standard irradiation geometries, and the irradiation source included 20 monoenergetic photon energies ranging from 0.01 MeV to 10 MeV. The results indicate that the postures, location of the organs, and irradiation geometries have an impact on the dose conversion coefficients. With the same irradiation geometry, the DCCKs of different organs are different; when the photon energy is from 0.02 MeV to 0.1 MeV, significant differences exist in the DCCK of phantoms of various postures, and the maximum relative deviation is 80%. For the ECCKs, there are greater differences among phantoms of various postures with the same irradiation geometry when the photon energy is from 0.02 MeV to 0.05 MeV, and the maximum relative deviation is about 20%.
Collapse
Affiliation(s)
- Chunyu Liu
- *Environment Engineering Center, China Nuclear Power Technology Research Institute, Shenzhen 518028, China
| | | |
Collapse
|
26
|
Stepusin EJ, Long DJ, Marshall EL, Bolch WE. Assessment of different patient-to-phantom matching criteria applied in Monte Carlo-based computed tomography dosimetry. Med Phys 2017; 44:5498-5508. [PMID: 28777466 DOI: 10.1002/mp.12502] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 06/14/2017] [Accepted: 07/25/2017] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To quantify differences in computationally estimated computed tomography (CT) organ doses for patient-specific voxel phantoms to estimated organ doses in matched computational phantoms using different matching criteria. MATERIALS AND METHODS Fifty-two patient-specific computational voxel phantoms were created through CT image segmentation. In addition, each patient-specific phantom was matched to six computational phantoms of the same gender based, respectively, on age and gender (reference phantoms), height and weight, effective diameter (both central slice and exam range average), and water equivalent diameter (both central slice and exam range average). Each patient-specific phantom and matched computational phantom were then used to simulate six different torso examinations using a previously validated Monte Carlo CT dosimetry methodology that accounts for tube current modulation. Organ doses for each patient-specific phantom were then compared with the organ dose estimates of each of the matched phantoms. RESULTS Relative to the corresponding patient-specific phantoms, the root mean square of the difference in organ dose was 39.1%, 20.3%, 22.7%, 21.6%, 20.5%, and 17.6%, for reference, height and weight, effective diameter (central slice and scan average), and water equivalent diameter (central slice and scan average), respectively. The average magnitude of difference in organ dose was 24%, 14%, 16.9%, 16.2%, 14%, and 11.9%, respectively. CONCLUSION Overall, these data suggest that matching a patient to a computational phantom in a library is superior to matching to a reference phantom. Water equivalent diameter is the superior matching metric, but it is less feasible to implement in a clinical and retrospective setting. For these reasons, height-and-weight matching is an acceptable and reliable method for matching a patient to a member of a computational phantom library with regard to CT dosimetry.
Collapse
Affiliation(s)
- Elliott J Stepusin
- J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, 32611-6131, USA
| | - Daniel J Long
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA
| | - Emily L Marshall
- J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, 32611-6131, USA
| | - Wesley E Bolch
- J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, 32611-6131, USA
| |
Collapse
|
27
|
Xie T, Kuster N, Zaidi H. Computational hybrid anthropometric paediatric phantom library for internal radiation dosimetry. Phys Med Biol 2017; 62:3263-3283. [DOI: 10.1088/1361-6560/aa63d0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
28
|
Sahbaee P, Abadi E, Segars WP, Marin D, Nelson RC, Samei E. The Effect of Contrast Material on Radiation Dose at CT: Part II. A Systematic Evaluation across 58 Patient Models. Radiology 2017; 283:749-757. [PMID: 28287916 DOI: 10.1148/radiol.2017152852] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Purpose To estimate the radiation dose as a result of contrast medium administration in a typical abdominal computed tomographic (CT) examination across a library of contrast material-enhanced computational patient models. Materials and Methods In part II of this study, first, the technique described in part I of this study was applied to enhance the extended cardiac-torso models with patient-specific iodine-time profiles reflecting the administration of contrast material. Second, the patient models were deployed to assess the patient-specific organ dose as a function of time in a typical abdominal CT examination using Monte Carlo simulation. In this hypothesis-generating study, organ dose refers to the total energy deposited in the unit mass of the tissue inclusive of iodine. Third, a study was performed as a strategy to anticipate the biologically relevant dose (absorbed dose to tissue) in highly perfused organs such as the liver and kidney. The time-varying organ-dose increment values relative to those for unenhanced CT examinations were reported. Results The results from the patient models subjected to the injection protocol indicated up to a total 53%, 30%, 35%, 54%, 27%, 18%, 17%, and 24% increase in radiation dose delivered to the heart, spleen, liver, kidneys, stomach, colon, small intestine, and pancreas, respectively. The biologically relevant dose increase with respect to the dose at an unenhanced CT examination was in the range of 0%-18% increase for the liver and 27% for the kidney across 58 patient models. Conclusion The administration of contrast medium increases the total radiation dose. However, radiation dose, while relevant to be included in estimating the risk associated with contrast-enhanced CT, may still not fully characterize the total biologic effects. Therefore, given the fact that many CT diagnostic decisions would be impossible without the use of iodine, this study suggests the need to consider the effect of iodinated contrast material on the organ doses to patients undergoing CT studies when designing CT protocols. © RSNA, 2017 Online supplemental material is available for this article.
Collapse
Affiliation(s)
- Pooyan Sahbaee
- From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.)
| | - Ehsan Abadi
- From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.)
| | - W Paul Segars
- From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.)
| | - Daniele Marin
- From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.)
| | - Rendon C Nelson
- From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.)
| | - Ehsan Samei
- From the Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705 (P.S., E.A., W.P.S., D.M., R.C.N., E.S.); and Department of Physics, North Carolina State University, Raleigh, NC (P.S.)
| |
Collapse
|
29
|
Sahbaee P, Segars WP, Marin D, Nelson RC, Samei E. The Effect of Contrast Material on Radiation Dose at CT: Part I. Incorporation of Contrast Material Dynamics in Anthropomorphic Phantoms. Radiology 2017; 283:739-748. [PMID: 28092496 DOI: 10.1148/radiol.2016152851] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Purpose To develop a method to incorporate the propagation of contrast material into computational anthropomorphic phantoms for estimation of organ dose at computed tomography (CT). Materials and Methods A patient-specific physiologically based pharmacokinetic (PBPK) model of the human cardiovascular system was incorporated into 58 extended cardiac-torso (XCAT) patient phantoms. The PBPK model comprised compartmental models of vessels and organs unique to each XCAT model. For typical injection protocols, the dynamics of the contrast material in the body were described according to a series of patient-specific iodine mass-balance differential equations, the solutions to which provided the contrast material concentration time curves for each compartment. Each organ was assigned to a corresponding time-varying iodinated contrast agent to create the contrast material-enhanced five-dimensional XCAT models, in which the fifth dimension represents the dynamics of contrast material. To validate the accuracy of the models, simulated aortic and hepatic contrast-enhancement results throughout the models were compared with previously published clinical data by using the percentage of discrepancy in the mean, time to 90% peak, peak value, and slope of enhancement in a paired t test at the 95% significance level. Results The PBPK model allowed effective prediction of the time-varying concentration curves of various contrast material administrations in each organ for different patient models. The contrast-enhancement results were in agreement with results of previously published clinical data, with mean percentage, time to 90% peak, peak value, and slope of less than 10% (P > .74), 4%, 7%, and 14% for uniphasic and 12% (P > .56), 4%, 12%, and 14% for biphasic injection protocols, respectively. The exception was hepatic enhancement results calculated for a uniphasic injection protocol for which the discrepancy was less than 25%. Conclusion A technique to model the propagation of contrast material in XCAT human models was developed. The models with added contrast material propagation can be applied to simulate contrast-enhanced CT examinations. © RSNA, 2017 Online supplemental material is available for this article.
Collapse
Affiliation(s)
- Pooyan Sahbaee
- From the Carl E. Ravin Advanced Imaging Laboratories (P.S., W.P.S., E.S.) and Departments of Radiology (P.S., D.M., R.C.N., E.S.), Medical Physics Graduate Program (W.P.S., E.S.), and Biomedical Engineering, Electrical and Computer Engineering, and Physics (E.S.), Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705; and Department of Physics, NC State University, Raleigh, NC (P.S.)
| | - W Paul Segars
- From the Carl E. Ravin Advanced Imaging Laboratories (P.S., W.P.S., E.S.) and Departments of Radiology (P.S., D.M., R.C.N., E.S.), Medical Physics Graduate Program (W.P.S., E.S.), and Biomedical Engineering, Electrical and Computer Engineering, and Physics (E.S.), Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705; and Department of Physics, NC State University, Raleigh, NC (P.S.)
| | - Daniele Marin
- From the Carl E. Ravin Advanced Imaging Laboratories (P.S., W.P.S., E.S.) and Departments of Radiology (P.S., D.M., R.C.N., E.S.), Medical Physics Graduate Program (W.P.S., E.S.), and Biomedical Engineering, Electrical and Computer Engineering, and Physics (E.S.), Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705; and Department of Physics, NC State University, Raleigh, NC (P.S.)
| | - Rendon C Nelson
- From the Carl E. Ravin Advanced Imaging Laboratories (P.S., W.P.S., E.S.) and Departments of Radiology (P.S., D.M., R.C.N., E.S.), Medical Physics Graduate Program (W.P.S., E.S.), and Biomedical Engineering, Electrical and Computer Engineering, and Physics (E.S.), Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705; and Department of Physics, NC State University, Raleigh, NC (P.S.)
| | - Ehsan Samei
- From the Carl E. Ravin Advanced Imaging Laboratories (P.S., W.P.S., E.S.) and Departments of Radiology (P.S., D.M., R.C.N., E.S.), Medical Physics Graduate Program (W.P.S., E.S.), and Biomedical Engineering, Electrical and Computer Engineering, and Physics (E.S.), Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705; and Department of Physics, NC State University, Raleigh, NC (P.S.)
| |
Collapse
|
30
|
Pi Y, Zhang L, Huo W, Feng M, Chen Z, Xu XG. Development and application of a set of mesh-based and age-dependent Chinese family phantoms for radiation protection dosimetry: Preliminary Data for external photon beams. EPJ WEB OF CONFERENCES 2017. [DOI: 10.1051/epjconf/201715304014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
31
|
Saporito S, Dovancescu S, Herold IHF, van den Bosch HCM, van Assen HC, Aarts RM, Korsten HHM, Mischi M. Comparison of cardiac magnetic resonance imaging and bio-impedance spectroscopy for the assessment of fluid displacement induced by external leg compression. Physiol Meas 2016; 38:15-32. [DOI: 10.1088/1361-6579/38/1/15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
32
|
Gyekye PK, Becker F, Mensah SY, Emi-Reynolds G. OPTIMISATION OF SCATTER RADIATION TO STAFF DURING CT-FLUOROSCOPY: MONTE CARLO STUDIES. RADIATION PROTECTION DOSIMETRY 2016; 170:393-397. [PMID: 27247445 DOI: 10.1093/rpd/ncw135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 05/13/2016] [Indexed: 06/05/2023]
Abstract
Studies have shown that there is high radiation exposure to medical staff during computed tomography fluoroscopy (CTF)-guided procedures. This study aims to investigate staff dose reduction techniques considering the CTF gantry positioning in the room and room dimensions in addition to the conventional use of thyroid collars, aprons and eye goggles. A Toshiba Aquilion One 640 slice CT scanner and CTF room were modelled using SimpleGeo. Standing and supine adult mesh phantoms were used to represent the staff and patient. The models were spatially put together on one platform using VOXEL2MCNP. Based on this, MCNPX input files were generated for the studies. CTF gantry and staff positions, and CTF room size were varied for different scenarios. Effective, eye lens and thyroid dose to staff were estimated for each scenario. Additional means of possible dose reduction with respect to positioning of the CTF device and room layout are discussed.
Collapse
Affiliation(s)
- P K Gyekye
- Radiation Protection Institute, Ghana Atomic Energy Commission, Accra, Ghana
| | - F Becker
- Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - S Y Mensah
- College of Agriculture and Natural Sciences, University of Cape Coast, Cape Coast, Ghana
| | - G Emi-Reynolds
- Radiation Protection Institute, Ghana Atomic Energy Commission, Accra, Ghana
| |
Collapse
|
33
|
Chen Y, Song Y, Ma J, Zhao J. Optimization-based scatter estimation using primary modulation for computed tomography. Med Phys 2016; 43:4753. [DOI: 10.1118/1.4958680] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
|
34
|
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.
Collapse
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
| |
Collapse
|
35
|
Jansen JTM, Shrimpton PC. Development of Monte Carlo simulations to provide scanner-specific organ dose coefficients for contemporary CT. Phys Med Biol 2016; 61:5356-77. [DOI: 10.1088/0031-9155/61/14/5356] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
36
|
Liew TS, Schilthuizen M. A Method for Quantifying, Visualising, and Analysing Gastropod Shell Form. PLoS One 2016; 11:e0157069. [PMID: 27280463 PMCID: PMC4900530 DOI: 10.1371/journal.pone.0157069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 05/24/2016] [Indexed: 11/20/2022] Open
Abstract
Quantitative analysis of organismal form is an important component for almost every branch of biology. Although generally considered an easily-measurable structure, the quantification of gastropod shell form is still a challenge because many shells lack homologous structures and have a spiral form that is difficult to capture with linear measurements. In view of this, we adopt the idea of theoretical modelling of shell form, in which the shell form is the product of aperture ontogeny profiles in terms of aperture growth trajectory that is quantified as curvature and torsion, and of aperture form that is represented by size and shape. We develop a workflow for the analysis of shell forms based on the aperture ontogeny profile, starting from the procedure of data preparation (retopologising the shell model), via data acquisition (calculation of aperture growth trajectory, aperture form and ontogeny axis), and data presentation (qualitative comparison between shell forms) and ending with data analysis (quantitative comparison between shell forms). We evaluate our methods on representative shells of the genera Opisthostoma and Plectostoma, which exhibit great variability in shell form. The outcome suggests that our method is a robust, reproducible, and versatile approach for the analysis of shell form. Finally, we propose several potential applications of our methods in functional morphology, theoretical modelling, taxonomy, and evolutionary biology.
Collapse
Affiliation(s)
- Thor-Seng Liew
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
- Institute Biology Leiden, Leiden University, P.O. Box 9516, 2300 RA, Leiden, The Netherlands
- Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA, Leiden, The Netherlands
| | - Menno Schilthuizen
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
- Institute Biology Leiden, Leiden University, P.O. Box 9516, 2300 RA, Leiden, The Netherlands
- Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA, Leiden, The Netherlands
| |
Collapse
|
37
|
Yeom YS, Kim HS, Nguyen TT, Choi C, Han MC, Kim CH, Lee JK, Zankl M, Petoussi-Henss N, Bolch WE, Lee C, Chung BS. New small-intestine modeling method for surface-based computational human phantoms. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2016; 36:230-245. [PMID: 27007802 DOI: 10.1088/0952-4746/36/2/230] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
When converting voxel phantoms to a surface format, the small intestine (SI), which is usually not accurately represented in a voxel phantom due to its complex and irregular shape on one hand and the limited voxel resolutions on the other, cannot be directly converted to a high-quality surface model. Currently, stylized pipe models are used instead, but they are strongly influenced by developer's subjectivity, resulting in unacceptable geometric and dosimetric inconsistencies. In this paper, we propose a new method for the construction of SI models based on the Monte Carlo approach. In the present study, the proposed method was tested by constructing the SI model for the polygon-mesh version of the ICRP reference male phantom currently under development. We believe that the new SI model is anatomically more realistic than the stylized SI models. Furthermore, our simulation results show that the new SI model, for both external and internal photon exposures, leads to dose values that are more similar to those of the original ICRP male voxel phantom than does the previously constructed stylized SI model.
Collapse
Affiliation(s)
- Yeon Soo Yeom
- Department of Nuclear Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791, Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Optimization-based scatter estimation using semi-transparent beam absorber array. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:5634-7. [PMID: 26737570 DOI: 10.1109/embc.2015.7319670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To correct the scatter in cone beam CT, an optimization-based scatter estimation method (OPMSE) is proposed. Like the previous Fourier-based primary modulation method (FPMSE), semi-transparent beam absorber array (SBAA) is placed between the X-ray source and the imaging target, thus projection data behind the absorber can still be obtained, which is meaningful for dose saving and image quality improving. In the proposed algorithm, scatter is estimated by solving an optimization problem, which makes use of the prior information that primary and scatter are both smooth not only in each frame, but also between adjacent frames. Moreover, an edge-preserving weighting is incorporated to prevent the over-smoothing of structures in the primary signal. The new algorithm is robust that various patterns of modulator can be applied. Simulation and physical experiments demonstrated the good performance of OPMSE in scatter removing.
Collapse
|
39
|
Marcatili S, Villoing D, Garcia MP, Bardiès M. Multi-scale hybrid models for radiopharmaceutical dosimetry with Geant4. Phys Med Biol 2016; 59:7625-41. [PMID: 25415621 DOI: 10.1088/0031-9155/59/24/7625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The accuracy of radiopharmaceutical absorbed dose distributions computed through Monte Carlo (MC) simulations is mostly limited by the low spatial resolution of 3D imaging techniques used to define the simulation geometry. This issue also persists with the implementation of realistic hybrid models built using polygonal mesh and/or NURBS as they require to be simulated in their voxel form in order to reduce computation times. The existing trade-off between voxel size and simulation speed leads on one side, in an overestimation of the size of small radiosensitive structures such as the skin or hollow organs walls and, on the other, to unnecessarily detailed voxelization of large, homogeneous structures.We developed a set of computational tools based on VTK and Geant4 in order to build multi-resolution organ models. Our aim is to use different voxel sizes to represent anatomical regions of different clinical relevance: the MC implementation of these models is expected to improve spatial resolution in specific anatomical structures without significantly affecting simulation speed. Here we present the tools developed through a proof of principle example. Our approach is validated against the standard Geant4 technique for the simulation of voxel geometries.
Collapse
Affiliation(s)
- S Marcatili
- UMR 1037 INSERM-Centre de Recherche en Cancérologie de Toulouse, Toulouse, France
| | | | | | | |
Collapse
|
40
|
Evaluation of the medical and occupational shielding in cerebral angiography using Monte Carlo simulations and virtual anthropomorphic phantoms. Radiat Phys Chem Oxf Engl 1993 2015. [DOI: 10.1016/j.radphyschem.2015.07.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
41
|
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
|
42
|
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
|
43
|
Geng C, Tang X, Qian W, Guan F, Johns J, Yu H, Gong C, Shu D, Chen D. Calculations of S values and effective dose for the radioiodine carrier and surrounding individuals based on Chinese hybrid reference phantoms using the Monte Carlo technique. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2015; 35:707-717. [PMID: 26344387 DOI: 10.1088/0952-4746/35/3/707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The S values for the thyroid as the radioiodine source organ to other target organs were investigated using Chinese hybrid reference phantoms and the Monte Carlo code MCNP5. Two radioiodine isotopes (125)I and (131)I uniformly distributed in the thyroid were investigated separately. We compared our S values for (131)I in Chinese phantoms with previous studies using other types of phantoms: Oak Ridge National Laboratory (ORNL) stylized phantoms, International Commission on Radiological Protection (ICRP) voxel phantoms, and University of Florida (UF) phantoms. Our results are much closer to the UF phantoms. For each specific target organ, the S value for (131)I is larger than for (125)I in both male and female phantoms. In addition, the S values and effective dose to surrounding face-to-face exposed individuals, including different genders and ages (10- and 15-year-old juniors, and adults) from an adult male radioiodine carrier were also investigated. The target organ S values and effective dose for surrounding individuals obey the inverse square law with the distance between source and target phantoms. The obtained effective dose data in Chinese phantoms are comparable to the results in a previous study using the UF phantoms. The data generated in this study can serve as the reference to make recommendations for radiation protection of the Chinese patients or nuclear workers.
Collapse
Affiliation(s)
- Changran Geng
- Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, People's Republic of China. Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, People's Republic of China. Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
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.
Collapse
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
| |
Collapse
|
45
|
Xie T, Lee C, Bolch WE, Zaidi H. Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models. Med Phys 2015; 42:2955-66. [PMID: 26127049 PMCID: PMC5148206 DOI: 10.1118/1.4921364] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 04/24/2015] [Accepted: 05/08/2015] [Indexed: 12/26/2022] Open
Abstract
PURPOSE Nuclear cardiology plays an important role in clinical assessment and has enormous impact on the management of a variety of cardiovascular diseases. Pediatric patients at different age groups are exposed to a spectrum of radiation dose levels and associated cancer risks different from those of adults in diagnostic nuclear medicine procedures. Therefore, comprehensive radiation dosimetry evaluations for commonly used myocardial perfusion imaging (MPI) and viability radiotracers in target population (children and adults) at different age groups are highly desired. METHODS Using Monte Carlo calculations and biological effects of ionizing radiation VII model, we calculate the S-values for a number of radionuclides (Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82) and estimate the absorbed dose and effective dose for 12 MPI radiotracers in computational models including the newborn, 1-, 5-, 10-, 15-yr-old, and adult male and female computational phantoms. RESULTS For most organs, (201)Tl produces the highest absorbed dose whereas (82)Rb and (15)O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of (82)Rb is 48% and 77% lower than that of (99m)Tc-tetrofosmin (rest), respectively. CONCLUSIONS (82)Rb results in lower effective dose in adults compared to (99m)Tc-labeled tracers. However, this advantage is less apparent in children. The produced dosimetric databases for various radiotracers used in cardiovascular imaging, using new generation of computational models, can be used for risk-benefit assessment of a spectrum of patient population in clinical nuclear cardiology practice.
Collapse
Affiliation(s)
- Tianwu Xie
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211, Switzerland
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852
| | - Wesley E Bolch
- Departments of Nuclear & Radiological and Biomedical Engineering, University of Florida, Gainesville, Florida 32611
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211, Switzerland; Geneva Neuroscience Center, Geneva University, Geneva CH-1205, Switzerland; and Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, Netherlands
| |
Collapse
|
46
|
Dong L, Li T, Liu C. Construction of hybrid Chinese reference adult phantoms and estimation of dose conversion coefficients for muons. RADIATION PROTECTION DOSIMETRY 2015; 164:219-227. [PMID: 25313173 DOI: 10.1093/rpd/ncu300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 09/06/2014] [Indexed: 06/04/2023]
Abstract
A set of fluence-to-effective dose conversion coefficients of external exposure to muons were investigated for Chinese hybrid phantom references, which include both male and female. Both polygon meshes and Non-Uniform Rational B-Spline (NURBS) surfaces were used to descried the boundary of the organs and tissues in these phantoms. The 3D-DOCTOR and Rhinoceros software were used to polygonise the colour slice images and generate the NURBS surfaces, respectively. The voxelisation is completed using the BINVOX software and the assembly finished by using MATLAB codes. The voxel resolutions were selected to be 0.22 × 0.22 × 0.22 cm(3) and 0.2 × 0.2 × 0.2 cm(3) for male and female phantoms, respectively. All parts of the final phantoms were matched to their reference organ masses within a tolerance of ±5%. The conversion coefficients for negative and positive muons were calculated with the FLUKA transport code. There were 21 external monoenergetic beams ranging from 0.01 GeV to 100 TeV in 5 different geometrical conditions of irradiation.
Collapse
Affiliation(s)
- Liang Dong
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001, China
| | - Taosheng Li
- Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Chunyu Liu
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001, China
| |
Collapse
|
47
|
Han MC, Yeom YS, Kim CH, Kim S, Sohn JW. New approach based on tetrahedral-mesh geometry for accurate 4D Monte Carlo patient-dose calculation. Phys Med Biol 2015; 60:1601-12. [DOI: 10.1088/0031-9155/60/4/1601] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
48
|
Dosimetric study of a brachytherapy treatment of esophagus with Brazilian 192Ir sources using an anthropomorphic phantom. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2013.11.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
49
|
Fonseca TCF, Bogaerts R, Hunt J, Vanhavere F. A methodology to develop computational phantoms with adjustable posture for WBC calibration. Phys Med Biol 2014; 59:6811-25. [DOI: 10.1088/0031-9155/59/22/6811] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
50
|
Xu XG. An exponential growth of computational phantom research in radiation protection, imaging, and radiotherapy: a review of the fifty-year history. Phys Med Biol 2014; 59:R233-302. [PMID: 25144730 PMCID: PMC4169876 DOI: 10.1088/0031-9155/59/18/r233] [Citation(s) in RCA: 161] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Radiation dose calculation using models of the human anatomy has been a subject of great interest to radiation protection, medical imaging, and radiotherapy. However, early pioneers of this field did not foresee the exponential growth of research activity as observed today. This review article walks the reader through the history of the research and development in this field of study which started some 50 years ago. This review identifies a clear progression of computational phantom complexity which can be denoted by three distinct generations. The first generation of stylized phantoms, representing a grouping of less than dozen models, was initially developed in the 1960s at Oak Ridge National Laboratory to calculate internal doses from nuclear medicine procedures. Despite their anatomical simplicity, these computational phantoms were the best tools available at the time for internal/external dosimetry, image evaluation, and treatment dose evaluations. A second generation of a large number of voxelized phantoms arose rapidly in the late 1980s as a result of the increased availability of tomographic medical imaging and computers. Surprisingly, the last decade saw the emergence of the third generation of phantoms which are based on advanced geometries called boundary representation (BREP) in the form of Non-Uniform Rational B-Splines (NURBS) or polygonal meshes. This new class of phantoms now consists of over 287 models including those used for non-ionizing radiation applications. This review article aims to provide the reader with a general understanding of how the field of computational phantoms came about and the technical challenges it faced at different times. This goal is achieved by defining basic geometry modeling techniques and by analyzing selected phantoms in terms of geometrical features and dosimetric problems to be solved. The rich historical information is summarized in four tables that are aided by highlights in the text on how some of the most well-known phantoms were developed and used in practice. Some of the information covered in this review has not been previously reported, for example, the CAM and CAF phantoms developed in 1970s for space radiation applications. The author also clarifies confusion about 'population-average' prospective dosimetry needed for radiological protection under the current ICRP radiation protection system and 'individualized' retrospective dosimetry often performed for medical physics studies. To illustrate the impact of computational phantoms, a section of this article is devoted to examples from the author's own research group. Finally the author explains an unexpected finding during the course of preparing for this article that the phantoms from the past 50 years followed a pattern of exponential growth. The review ends on a brief discussion of future research needs (a supplementary file '3DPhantoms.pdf' to figure 15 is available for download that will allow a reader to interactively visualize the phantoms in 3D).
Collapse
Affiliation(s)
- X George Xu
- Rensselaer Polytechnic Institute Troy, New York, USA
| |
Collapse
|