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Yang F, Gao L. Age-based diagnostic reference levels and achievable doses for paediatric CT: a survey in Shanghai, China. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2024; 44:021509. [PMID: 38599187 DOI: 10.1088/1361-6498/ad3ce5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 04/10/2024] [Indexed: 04/12/2024]
Abstract
Computed tomography (CT) is extensively utilised in medical diagnostics due to its notable radiographic superiority. However, the cancer risk associated with CT examinations, particularly in children, is of significant concern. The assessment of cancer risk relies on the radiation dose to examinees. Diagnostic reference levels (DRLs) and achievable doses (ADs) were used to assess the level of radiation dose in CT examinations widely. Although the national DRLs of paediatric CT have been explored in China, few local DRLs at the city level have been assessed. To set up the local DRLs and ADs of paediatric CT, we investigated the radiation dose level for paediatric CT in Shanghai. In this survey, a total of 3061 paediatric CT examinations underwent in Shanghai in 2022 were selected by stratified sampling, and the dose levels in terms of volume CT dose index (CTDIvol) and the dose-length product (DLP) were analysed by 4 age groups. The DRLs and ADs were set at the 75th and 50th percentile of the distribution and compared with the previous studies at home and abroad. The survey results revealed that, for head scan, the DRLs of CTDIvolwere from 25 to 46 mGy, and the levels of DLP were from 340 to 663 mGy·cm. For chest, the DRLs of CTDIvolwere from 2.2 to 8.3 mGy, and the levels of DLP were from 42 to 223 mGy·cm. For abdomen, the DRLs of CTDIvolwere from 6.3 to 16 mGy, and the levels of DLP were from 181 to 557 mGy·cm. The ADs were about 60% lower than their corresponding DRLs. The levels of radiation doses in children-based hospitals were higher than those in other medical institutions (P< 0.001). In conclusion, there was still potential for reducing radiation dose of paediatric CT, emphasising the urgent need for optimising paediatric CT dose in Shanghai.
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Affiliation(s)
- Fanqiaochu Yang
- School of Public Health, Fudan University, Shanghai, People's Republic of China
| | - Linfeng Gao
- Shanghai Municipal Center for Disease Control & Prevention, Shanghai, People's Republic of China
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Amalaraj T, Jeyasugiththan J, Satharasinghe D, Pallewatte AS. Dose reference level based on size-specific dose estimate (SSDE) and feasibility of deriving effective body diameter using tube current and time product (mAs) for adult chest and abdomen computed tomography (CT) procedures. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2023; 43:011505. [PMID: 36626827 DOI: 10.1088/1361-6498/acb1bf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
This study aimed to establish dose reference level (NDRLSSDE) based on size-specific dose estimate (SSDE) derived using effective diameter (Deff) for adult chest and abdomen computed tomography (CT) procedures and to explore the feasibility of drivingDeffusing the product of tube current and time (mAs). In this retrospective study, dose data, scan parameters and patient body dimensions at the mid-slice level from 14 CT units (out of 63 total) were extracted. Additionally, the mAs values of the axial slice at the samez-location where the diameter measurements were made (mAsz) were recorded. Pearson's correlation (r) analysis was used to determine the relationship ofDeffwith patient BMI, weight, and mAsz. The NDRLSSDEfor the chest and abdomen were 9.72 mGy and 13.4 mGy, respectively. The BMI and body weight were less correlated (r= 0.24 andr= 0.33, respectively) withDeff. The correlation between mAszandDeffwas considerably strong (r= 0.78) and can be used to predictDeffaccurately. The absolute dose differences between SSDEs calculated using the AAPM-204 method and mAszwas less than 1.1 mGy (15%). Therefore, mAszis an efficient parameter to deriveDeff. Further, the direct conversion factors to estimate SSDEs at different locations along thez-direction in the scan region from corresponding mAs and CTDIvolwere calculated. The NDRLSSDEsuggested in the present study can be used as a reference for size-dependent dose optimisation in Sri Lanka, and existing NDRL based on CTDIvolunderestimate the average adult CT dose by 36.0% and 39.7% for chest and abdomen regions respectively. The results show that using mAszto determine SSDE is a simple and practical approach with an accuracy of 95% and 85% for abdomen and chest scans, respectively. However, the obtained linear relationship betweenDeffand mAs is highly dependent on the ATCM technique and the user-determined noise levels of the scanning protocol. Finally, the phantom study resulted in the strongest correlation (r= 0.99) between theDwzand mAsz, and the prediction of patient size would be more precise thanDeffmethod.
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Affiliation(s)
- T Amalaraj
- Department of Nuclear Science, University of Colombo, Colombo, Sri Lanka
| | | | | | - A S Pallewatte
- Department of Radiology, National Hospital of Sri Lanka, Colombo, Sri Lanka
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Patient size as a parameter for determining Diagnostic Reference Levels for paediatric Computed Tomography (CT) procedures. Phys Med 2022; 102:55-65. [PMID: 36126468 DOI: 10.1016/j.ejmp.2022.09.004] [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: 04/17/2022] [Revised: 08/28/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION The paediatric radiation dose has never been studied in Sri Lanka, nor has a national diagnostic reference level (NDRL) established. Therefore, the primary aim of this study was to propose diagnostic reference levels (DRL) and achievable dose (AD) values for paediatric CT examinations based on size. METHODS A total of 658 paediatric (0-15 years) non-contrast-enhanced (NC) studies of head, chest and abdomen regions performed during six months in two dedicated paediatric hospitals (out of the three such institutions in the country) were included. For head examinations, the dose indexes were analysed based on age, while for body examinations, both age and effective diameter (Deff) were used. The median and the third quartile of the pooled dose distribution were given as AD and NDRL, respectively. RESULTS The AD ranges for the head, chest and abdomen regions based on CTDIvol were 45.8-57.2 mGy, 2.9-10.0 mGy and 3.8-10.3 mGy. The corresponding NDRL ranges were 45.8-95.8 mGy, 3.5-14.1 mGy and 4.5-11.9 mGy. The AD ranges based on SSDEdeff and deff were 3.5-9.6 mGy and 4.1-10.3 mGy in chest and abdomen regions. The corresponding NDRL were 4.5-14.1 mGy and 6.1-10.6 mGy. CONCLUSION Other institutions can use the present study DRLs as a reference dose for paediatric CT. The AD values can be used as a baseline for target dose optimisations, reducing doses up to 90%.
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Sapignoli S, Roggio A, Boschini A, Guida F, Merlo C, Paiusco M, Zorz A, De Monte F. Size-specific dose estimates for pediatric head CT protocols based on the AAPM report TG-293. Phys Med 2022; 100:26-30. [PMID: 35717776 DOI: 10.1016/j.ejmp.2022.06.004] [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: 02/15/2022] [Revised: 04/26/2022] [Accepted: 06/11/2022] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To establish the Size Specific Dose Estimate (SSDE) typical values for pediatric head CT examinations based on the AAPM report TG-293; to provide a new stratification based on the water-equivalent diameter (Dw), given that SSDE is related to the head size. METHODS 296 Head CT scans of pediatric patients collected using a dose monitoring software were retrospectively analysed. Typical values were derived stratifying data by age in three methods: the first proposed by the European Guidelines on Diagnostic Reference Levels for Pediatric Imaging (RP185), the second by the National Istisan Report 20/22 and a local one related to the clinical protocols (LStrata). For each scan, a self-developed Matlab routine calculated the water-equivalent diameter (Dw) and related SSDE values with the conversion factors fH16and fB16provided by the AAPM reports TG-293 and TG-204, respectively. Eventually, a Dwstratification was introduced starting from a measure of the lateral dimension of the head. RESULTS SSDE based on TG-204 overestimatesthe dose up to 12%. Four Dwgroups were identified thanks to the good correlation between the head lateral dimension andDw: Dw < 14 cm, 14 ≤ Dw < 16 cm, 16 ≤ Dw< 17 cm, Dw≥ 17 cm. The Dw-stratified dosimetric indices presentgreater variability than those grouped by age because of the large variability of the size of the infant's head. CONCLUSIONS The variability of the SSDE metric underlines that age-optimized protocols are not when size is considered.
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Affiliation(s)
- Sonia Sapignoli
- Medical Physics Department, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy
| | - Antonella Roggio
- Medical Physics Department, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy
| | - Alessio Boschini
- Medical Physics Department, Azienda ULSS2 Marca Trevigiana, Treviso, Italy
| | - Federica Guida
- Medical Physics Department, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy
| | - Carlo Merlo
- Medical Physics Department, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy
| | - Marta Paiusco
- Medical Physics Department, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy
| | - Alessandra Zorz
- Medical Physics Department, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy
| | - Francesca De Monte
- Medical Physics Department, Veneto Institute of Oncology IOV - IRCCS, Padua, Italy.
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Paydar R, Tahmasebzadeh A, Maziyar A, Reiazi R, Kermanshahi M, Anijdan SM. Pediatric effective dose assessment for routine computed tomography examinations in Tehran, Iran. JOURNAL OF MEDICAL SIGNALS & SENSORS 2022; 12:227-232. [PMID: 36120406 PMCID: PMC9480506 DOI: 10.4103/jmss.jmss_115_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 03/17/2022] [Accepted: 04/19/2022] [Indexed: 11/30/2022]
Abstract
Background: The purpose of this study is to evaluate the effective dose (ED) for computed tomography (CT) examination in different age groups and medical exposure in pediatric imaging centers in Tehran, Iran. Methods: Imaging data were collected from 532 pediatric patients from four age groups subjected to three prevalent procedures. National Cancer Institute CT (NCICT) software was used to calculate the ED value. Results: The mean ED values were 1.60, 4.16, and 10.56 mSv for patients' procedures of head, chest, and abdomen–pelvis, respectively. This study showed a significant difference of ED value among five pediatric medical imaging centers (P < 0.05). In head, chest, and abdomen–pelvis exams, a reduction in ED was evident with decreasing patients' age. Conclusion: As there were significant differences among ED values in five pediatric medical imaging centers, optimizing this value is necessary to decrease this variation. For head CT in infants and also abdomen–pelvis, further reduction in radiation exposure is required.
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Satharasinghe DM, Jeyasugiththan J, Wanninayake WMNMB, Pallewatte AS. Size-specific dose estimates (SSDEs) for computed tomography and influencing factors on it: a systematic review. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:R108-R124. [PMID: 34428755 DOI: 10.1088/1361-6498/ac20b0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
The actual dose received during a computed tomography (CT) examination depends on both the patient size and the radiation output of the scanner. To represent the actual patient morphometry, a new radiation dose metric named size-specific dose estimates (SSDEs) was developed by the American Association of Physicists in Medicine in 2011. The purpose of this article is to review the SSDE concept and the factors influencing it. Moreover, the appropriate methodology of SSDE determination and the application of SSDE as a diagnostic reference-level quantity is critically analyzed based on the data available in the literature. It is expected that this review could potentially increase awareness among CT users of the effective utilization of SSDE as a tool to aid in the optimization of radiation dose in CT.
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Affiliation(s)
- D M Satharasinghe
- Department of Nuclear Science, University of Colombo, Colombo 03, Sri Lanka
- Horizon Campus, Malabe, Sri Lanka
| | - J Jeyasugiththan
- Department of Nuclear Science, University of Colombo, Colombo 03, Sri Lanka
| | | | - A S Pallewatte
- Department of Radiology, National Hospital of Sri Lanka, Colombo, Sri Lanka
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Satharasinghe DM, Jeyasugiththan J, Wanninayake WMNMB, Pallewatte AS. Paediatric diagnostic reference levels in computed tomography: a systematic review. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:R1-R27. [PMID: 33684071 DOI: 10.1088/1361-6498/abd840] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study aims to review the existing literature on diagnostic reference levels (DRLs) in paediatric computed tomography (CT) procedures and the methodologies for establishing them. A comprehensive literature search was done in the popular databases such as PubMed and Google Scholar under the key words 'p(a)ediatric DRL', 'dose reference level', 'diagnostic reference level' and 'DRL'. Twenty-three articles originating from 15 countries were included. Differences were found in the methods used to establish paediatric CT DRLs across the world, including test subjects, reference phantom size, anatomical regions, modes of data collection and stratification techniques. The majority of the studies were based on retrospective patient surveys. The head, chest and abdomen were the common regions. The volume computed tomography dose index (CTDIvol) and dose-length product (DLP) were the dosimetric quantities chosen in the majority of publications. However, the size-specific dose estimate was a growing trend in the DRL concept of CT. A 16 cm diameter phantom was used by most of the publications when defining DRLs for head, chest and abdomen. The majority of the DRLs were given based on patient age, and the common age categories for head, chest and abdomen regions were 0-1, 1-5, 5-10 and 10-15 years. The DRL ranges for the head region were 18-68 mGy (CTDIvol) and 260-1608 mGy cm (DLP). For chest and abdomen regions the variations were 1.0-15.6 mGy, 10-496 mGy cm and 1.8-23 mGy, 65-807 mGy cm, respectively. All these DRLs were established for children aged 0-18 years. The wide range of DRL distributions in chest and abdomen regions can be attributed to the use of two different reference phantom sizes (16 and 32 cm), failure to follow a common methodology and inadequate dose optimisation actions. Therefore, an internationally accepted protocol should be followed when establishing DRLs. Moreover, these DRL variations suggest the importance of establish a national DRL for each country considering advanced techniques and dose reduction methodologies.
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Affiliation(s)
- D M Satharasinghe
- Department of Nuclear Science, University of Colombo, Colombo, Sri Lanka. Horizon Campus, Malabe, Sri Lanka
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Tahmasebzadeh A, Paydar R, Soltani Kermanshahi M, Maziar A, Rezaei M, Reiazi R. PEDIATRIC REGIONAL DRL ASSESSMENT IN COMMON CT EXAMINATIONS FOR MEDICAL EXPOSURE OPTIMIZATION IN TEHRAN, IRAN. RADIATION PROTECTION DOSIMETRY 2020; 192:341-349. [PMID: 33338233 DOI: 10.1093/rpd/ncaa192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 10/09/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
The main purpose of this pilot study was to assess the regional diagnostic reference level (RDRL) of computed tomography (CT) examinations to optimise medical exposure in five pediatric medical imaging centers in Tehran, Iran where the most frequent CT examinations were investigated. For each patient, CT volume dose indexes (CTDIvol) and dose length product (DLP) in each group were recorded and their third quartile was calculated and set as RDRL. Pediatrics were divided into four age groups (<1; 1-5; 5-10 and 10-15 years). Then, the third quartile values for head, chest and abdomen-pelvic CTs were, respectively, calculated for each group in terms of CTDIvol: 21.3, 24.4, 24.2 and 36.3 mGy; 2.9, 3.2, 3.7 and 5.7 mGy; 3.7, 5.7, 6.3 and 6.8 mGy; and in terms of DLP: 322.2, 390.1, 424.9 and 694.1 mGy.cm; 53.1, 115.2, 145.3 and 167.6 mGy.cm and 128.7, 317.7, 460.2 and 813.8 mGy.cm. Finally, RDRLs were compared with other countries and preceding data in Iran. As a result, CTDIVOL values were lower than other national and international studies except for chest and abdomen-pelvic values obtained in Europe. Moreover, this matter applied to DLP so that other formerly reported values were higher than the present study but European values for chest and abdomen-pelvic scans and also Tehran studies conducted in 2012. Variation of scan parameters (tube voltage (kVp), tube current (mAs) and scan length), CTDIvol and DLP of different procedures among different age groups were statistically significant (P-value < 0.05). The variations in dose between CT departments as well as between identical scanners suggest a large potential for optimization of examinations relative to which this study provides helpful data.
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Affiliation(s)
- Atefeh Tahmasebzadeh
- Research Committee, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Paydar
- Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran
- Radiation Science Department, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mojtaba Soltani Kermanshahi
- Social Determinants of Health Research Center, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Asghar Maziar
- Radiation Science Department, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Rezaei
- Department of Orthopedic, Tehran University of Medical Science, Tehran, Iran
| | - Reza Reiazi
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Anam C, Adhianto D, Sutanto H, Adi K, Ali MH, Rae WID, Fujibuchi T, Dougherty G. Comparison of central, peripheral, and weighted size-specific dose in CT. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2020; 28:695-708. [PMID: 32773401 PMCID: PMC7505003 DOI: 10.3233/xst-200667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/02/2020] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
The objective of this study is to determine X-ray dose distribution and the correlation between central, peripheral and weighted-centre peripheral doses for various phantom sizes and tube voltages in computed tomography (CT). We used phantoms developed in-house, with various water-equivalent diameters (Dw) from 8.5 up to 42.1 cm. The phantoms have one hole in the centre and four holes at the periphery. By using these five holes, it is possible to measure the size-specific central dose (Ds,c), peripheral dose (Ds,p), and weighted dose (Ds,w).The phantoms are scanned using a CT scanner (Siemens Somatom Definition AS), with the tube voltage varied from 80 up to 140 kVps. The doses are measured using a pencil ionization chamber (Ray safe X2 CT Sensor) in every hole for all phantoms. The relationships between Ds,c, Ds,p, and Ds,w, and the water-equivalent diameter are established. The size-conversion factors are calculated. Comparisons between Ds,c, Ds,p, and Ds,ware also established. We observe that the dose is relatively homogeneous over the phantom for water-equivalent diameters of 12-14 cm. For water-equivalent diameters less than 12 cm, the dose in the centre is higher than at the periphery, whereas for water-equivalent diameters greater than 14 cm, the dose at the centre is lower than that at the periphery. We also find that the distribution of the doses is influenced by the tube voltage. These dose distributions may be useful for calculating organ doses for specific patients using their CT images in future clinical practice.
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Affiliation(s)
- Choirul Anam
- Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang, Central Java, Indonesia
| | - Dwi Adhianto
- Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang, Central Java, Indonesia
| | - Heri Sutanto
- Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang, Central Java, Indonesia
| | - Kusworo Adi
- Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang, Central Java, Indonesia
| | - Mohd Hanafi Ali
- Discipline of Medical Imaging Science, Sydney School of Health Sciences, Faculty of Medicine and Health, The University of Sydney, C42 Cumberland Campus, NSW, Australia
| | - William Ian Duncombe Rae
- Discipline of Medical Imaging Science, Sydney School of Health Sciences, Faculty of Medicine and Health, The University of Sydney, C42 Cumberland Campus, NSW, Australia
| | - Toshioh Fujibuchi
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Geoff Dougherty
- Department of Applied Physics and Medical Imaging, California State University Channel Islands, Camarillo, CA, USA
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