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He J, Zhanjian C, Zheng J, Shentong M, Daoud MS, Hongyu Z, Eftekhari-Zadeh E, Guoqiang X. Application of MLP neural network to predict X-ray spectrum from tube voltage, filter material, and filter thickness used in medical imaging systems. PLoS One 2023; 18:e0294080. [PMID: 38060542 PMCID: PMC10703281 DOI: 10.1371/journal.pone.0294080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 10/24/2023] [Indexed: 12/18/2023] Open
Abstract
The X-ray energy spectrum is crucial for image quality and dosage assessment in mammography, radiography, fluoroscopy, and CT which are frequently used for the diagnosis of many diseases including but not limited to patients with cardiovascular and cerebrovascular diseases. X-ray tubes have an electron filament (cathode), a tungsten/rubidium target (anode) oriented at an angle, and a metal filter (aluminum, beryllium, etc.) that may be placed in front of an exit window. When cathode electrons meet the anode, they generate X-rays with varied energies, creating a spectrum from zero to the electrons' greatest energy. In general, the energy spectrum of X-rays depends on the electron beam's energy (tube voltage), target angle, material, filter thickness, etc. Thus, each imaging system's X-ray energy spectrum is unique to its tubes. The primary goal of the current study is to develop a clever method for quickly estimating the X-ray energy spectrum for a variety of tube voltages, filter materials, and filter thickness using a small number of unique spectra. In this investigation, two distinct filters made of beryllium and aluminum with thicknesses of 0.4, 0.8, 1.2, 1.6, and 2 mm were employed to obtain certain limited X-ray spectra for tube voltages of 20, 30, 40, 50, 60, 80, 100, 130, and 150 kV. The three inputs of 150 Multilayer Perceptron (MLP) neural networks were tube voltage, filter type, and filter thickness to forecast the X-ray spectra point by point. After training, the MLP neural networks could predict the X-ray spectra for tubes with voltages between 20 and 150 kV and two distinct filters made of aluminum and beryllium with thicknesses between 0 and 2 mm. The presented methodology can be used as a suitable, fast, accurate and reliable alternative method for predicting X-ray spectrum in medical applications. Although a technique was put out in this work for a particular system that was the subject of Monte Carlo simulations, it may be applied to any genuine system.
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Affiliation(s)
- Jie He
- The First People’s Hospital of Fuyang, Hangzhou, China
| | - Cai Zhanjian
- Vasculocardiology Department, The Third People’s Hospital of Hangzhou, Hangzhou, China
| | - Jiadi Zheng
- Wenzhou Hospital of Traditional Chinese Medicine Affiliated to Zhejiang University of Chinese Medicine, Wenzhou, China
| | | | - Mohammad Sh. Daoud
- College of Engineering, Al Ain University, Abu Dhabi, United Arab Emirates
| | - Zhang Hongyu
- Shanghai Songjiang District Central Hospital, Shanghai, China
| | - Ehsan Eftekhari-Zadeh
- Institute of Optics and Quantum Electronics, Abbe Center of Photonics, Friedrich Schiller University Jena, Jena, Germany
| | - Xu Guoqiang
- Department of Neurology, Yongkang First People’s Hospital, Yongkang, China
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Zhanjian C, Zheng J, Shan L, Wei W, Zhu W, Lu Y, Zhang X, Guoqiang X. Proposing an intelligent technique based on radial basis function neural network to forecast the energy spectrum of diagnostic X-ray imaging systems. Appl Radiat Isot 2023; 200:110961. [PMID: 37531730 DOI: 10.1016/j.apradiso.2023.110961] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 07/10/2023] [Accepted: 07/25/2023] [Indexed: 08/04/2023]
Abstract
In digital subtraction angiography (digital subtraction total cerebral angiography), cardiac and macrovascular cardiography, anorectal radiology, fluoroscopy, and computed tomography (CT), a prior knowledge to X-ray energy spectrum is crucial for assessing the image quality and also calculating patient X-ray dosage. The present investigation's main objective is to propose an intelligent technique for faster calculating X-ray energy spectrum of medical imaging systems with different exposure settings of tube voltage, filter material, and thickness based on limited specific spectra. In this study, Monte Carlo N Particle (MCNP) simulation code was initially used to generate some limited X-ray spectra for tube voltages of 20, 30, 40, 50, 80, 100, 130, and 150 kV for two different filters of beryllium and aluminum with thicknesses of 0. 4, 0.8, 1.2, 1.6 and 2 mm. Tube voltage, type, and thickness of filter were used as the 3 inputs of 150 Radial Basis Function Neural Network (RBFNN) to forecast point by point of the X-ray spectrum. After training, the RBFNNs could forecast most of the X-ray spectra for tube voltages in the range of 20-150 kV and two various filters of aluminum and beryllium with thicknesses in the range of 0-2 mm.
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Affiliation(s)
- Cai Zhanjian
- Anorectal Department, The Third People's Hospital of Hangzaou, Hangzhou, 311115, China.
| | | | - Liu Shan
- Wenzhou Medical University, China.
| | - Wang Wei
- School of Pharmacy, Wenzhou Medical University, Wenzhou, 325000, China.
| | - Wenzong Zhu
- Zhejiang Chinese Medical University, Hangzhou, 310000, China.
| | - Yanjie Lu
- Department of Digital Media Technology, Hangzhou Dianzi University, Hangzhou, 310018, China.
| | - Xicai Zhang
- Pingyang Hospital Affiliated to Wenzhou Medical University, Wenzhou, China.
| | - Xu Guoqiang
- Yongkang First People's Hospital, Department of Neurology, China.
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Bouchikhi BA, Benhalouche S, Ati M, Khelassi Toutaoui N, Arbor N, Bendella SA, Dib ASA, Tebboune A, Belbachir AH, Taleb Ben Diab E. A GATE Monte Carlo framework for dosimetric evaluation in mammography in an Algerian hospital. Appl Radiat Isot 2023; 197:110797. [PMID: 37043867 DOI: 10.1016/j.apradiso.2023.110797] [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: 08/26/2022] [Revised: 03/24/2023] [Accepted: 03/28/2023] [Indexed: 04/14/2023]
Abstract
A framework has been developed for dosimetric evaluation in mammography, using the GATE Monte Carlo (MC) platform, to simulate a MAMMOMAT 3000 Nova mammograph (Siemens) available at the University Hospital Center "1st November 1954" of Oran (EHU Oran 1er Novembre, 1954), Algeria. Calculated quantities such half-value layer (HVL), Entrance Surface Dose (ESD) and Mean Glandular Dose (MGD) have been compared to experimental data in order to validate the modeling of mammography examinations. Results are consistent with previous studies and show a good agreement between measurements and Monte Carlo calculations. By varying the tube voltage from 25 to 35 kV, we have estimated an increasing of a factor of 2.4 in ESD, and a factor of 2.75 for the MGD in a breast phantom. Furthermore, the current intensity of 100 mAs used for a beam quality combination (Mo/Mo) Anode/filter was found suitable for the tube voltages of 25-29 keV since the MGD does not exceed the limits set by the different quality insurance protocols. This GATE dose calculation framework thus provides a very useful tool for the optimization of mammography examinations at Oran hospital by allowing a better estimation of the dose delivered to patients according to the parameters of the examination.
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Affiliation(s)
- Billel Abdelaziz Bouchikhi
- Laboratoire d'Analyse et d'Application des Rayonnements (LAAR), Département de Génie physique, Université des Sciences et de la Technologie d'Oran, Mohamed Boudiaf USTO-MB, El Mnaouar, BP 1505, Bir El Djir, 31000, Oran, Algeria
| | - Saadia Benhalouche
- Laboratoire d'Analyse et d'Application des Rayonnements (LAAR), Département de Génie physique, Université des Sciences et de la Technologie d'Oran, Mohamed Boudiaf USTO-MB, El Mnaouar, BP 1505, Bir El Djir, 31000, Oran, Algeria.
| | - Moncef Ati
- Faculté de Médecine d'Oran, Université Oran 1 Ahmed Benbella, B.P 152, El M'Naouer, 31000, Oran, Algeria
| | | | - Nicolas Arbor
- Université de Strasbourg, IPHC, 23 Rue du Loess, 67037, Strasbourg, France; CNRS, UMR7178, 67037, Strasbourg, France
| | - Sid Ahmed Bendella
- Laboratoire d'Analyse et d'Application des Rayonnements (LAAR), Département de Génie physique, Université des Sciences et de la Technologie d'Oran, Mohamed Boudiaf USTO-MB, El Mnaouar, BP 1505, Bir El Djir, 31000, Oran, Algeria
| | - Anis Samy Amine Dib
- Laboratoire d'Analyse et d'Application des Rayonnements (LAAR), Département de Génie physique, Université des Sciences et de la Technologie d'Oran, Mohamed Boudiaf USTO-MB, El Mnaouar, BP 1505, Bir El Djir, 31000, Oran, Algeria
| | - Abdelghani Tebboune
- Laboratoire d'Analyse et d'Application des Rayonnements (LAAR), Département de Génie physique, Université des Sciences et de la Technologie d'Oran, Mohamed Boudiaf USTO-MB, El Mnaouar, BP 1505, Bir El Djir, 31000, Oran, Algeria
| | - Ahmed Hafid Belbachir
- Laboratoire d'Analyse et d'Application des Rayonnements (LAAR), Département de Génie physique, Université des Sciences et de la Technologie d'Oran, Mohamed Boudiaf USTO-MB, El Mnaouar, BP 1505, Bir El Djir, 31000, Oran, Algeria
| | - Esma Taleb Ben Diab
- Faculté de Médecine d'Oran, Université Oran 1 Ahmed Benbella, B.P 152, El M'Naouer, 31000, Oran, Algeria; Service d'imagerie médicale, Établissement Hospitalier Universitaire (EHU Oran), 1(er) Novembre 1954, Oran, Algeria
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Marshall NW, Bosmans H. Performance evaluation of digital breast tomosynthesis systems: physical methods and experimental data. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac9a35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 10/13/2022] [Indexed: 11/17/2022]
Abstract
Abstract
Digital breast tomosynthesis (DBT) has become a well-established breast imaging technique, whose performance has been investigated in many clinical studies, including a number of prospective clinical trials. Results from these studies generally point to non-inferiority in terms of microcalcification detection and superior mass-lesion detection for DBT imaging compared to digital mammography (DM). This modality has become an essential tool in the clinic for assessment and ad-hoc screening but is not yet implemented in most breast screening programmes at a state or national level. While evidence on the clinical utility of DBT has been accumulating, there has also been progress in the development of methods for technical performance assessment and quality control of these imaging systems. DBT is a relatively complicated ‘pseudo-3D’ modality whose technical assessment poses a number of difficulties. This paper reviews methods for the technical performance assessment of DBT devices, starting at the component level in part one and leading up to discussion of system evaluation with physical test objects in part two. We provide some historical and basic theoretical perspective, often starting from methods developed for DM imaging. Data from a multi-vendor comparison are also included, acquired under the medical physics quality control protocol developed by EUREF and currently being consolidated by a European Federation of Organisations for Medical Physics working group. These data and associated methods can serve as a reference for the development of reference data and provide some context for clinical studies.
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Liu Q, Suleiman ME, McEntee MF, Soh BP. Diagnostic reference levels in digital mammography: a systematic review. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:011503. [PMID: 34891143 DOI: 10.1088/1361-6498/ac4214] [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: 10/26/2021] [Accepted: 12/10/2021] [Indexed: 06/13/2023]
Abstract
Diagnostic reference levels (DRLs) in digital mammography (DM) serve as a useful benchmark for dose monitoring and optimisation, allowing comparison amongst countries, institutions and mammography units. A systematic review of DRLs in DM, published in 2014, reported a lack of consistent and internationally accepted protocol in DRLs establishment, thereby resulting in wide variations in methodologies which complicates comparability between studies. In 2017, the International Commission of Radiation Protection (ICRP) published additional guidelines and recommendations to provide clarity in the protocol used in DRLs establishment. With the continuing evolvement of technology, optimisation of examinations and updates in guidelines and recommendations, DRLs should be revised at regular intervals. This systematic review aims to provide an update and identify a more consistent protocol in the methodologies used to establish DRLs. Searches were conducted through Web of Science, PubMed-MEDLINE, ScienceDirect, CINAHL and Google Scholar, which resulted in 766 articles, of which 19 articles were included after screening. Relevant data from the included studies were summarised and analysed. While the additional guidelines and recommendations have provided clarifications in the methodologies used in DRLs establishment, such as data source (i.e. the preference to use data derived from patient instead of phantoms to establish DRLs), protocol (i.e. stratification of DRLs by compressed breast thickness and detector technology, and the use of median value for DRLs quantity instead of mean) and percentiles used to establish DRLs (i.e. set at the 75th percentile with a minimum sample size of 50 patients), other differences such as the lack of a standard dose calculation method used to estimate mean glandular dose continues to complicate comparisons between studies and different DM systems. This systematic review update incorporated the updated guidelines and recommendations from ICRP which will serve as a useful resource for future research efforts related to DRLs, dose monitoring and optimisation.
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Affiliation(s)
- Qiumei Liu
- Health and Social Sciences, Singapore Institute of Technology, Dover Road, Singapore
| | - Moayyad E Suleiman
- Faculty of Medicine and Health, The University of Sydney, Lidcombe, New South Wales, Australia
| | - Mark F McEntee
- The Discipline of Medical Imaging and Radiation Therapy, School of Medicine, UGF 12, Brookfield Health Sciences Complex, University College Cork, Cork, Ireland
| | - BaoLin P Soh
- Health and Social Sciences, Singapore Institute of Technology, Dover Road, Singapore
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Lee DY, Jo YI, Yang SH. Development of breast phantoms using a 3D printer and glandular dose evaluation. J Appl Clin Med Phys 2021; 22:270-277. [PMID: 34529348 PMCID: PMC8504594 DOI: 10.1002/acm2.13408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/04/2021] [Accepted: 08/16/2021] [Indexed: 11/29/2022] Open
Abstract
In this study, breast phantoms were fabricated by emulating glandular and adipose tissues separately using a three‐dimensional (3D) printer. In addition, direct and quantitative glandular dose evaluations were performed. A quantitative method was developed to evaluate the glandular and adipose tissues separately when performing glandular dose evaluations. The variables used for glandular dose evaluation were breast thickness, glandular tissue ratio, and additional filter materials. The values obtained using a Monte Carlo simulation and those measured using a glass dosimeter were compared and analyzed. The analysis showed that as the glandular tissue ratio increased, the dose decreased by approximately 10%, which is not a significant variation. The comparison revealed that the simulated values of the glandular dose were approximately 15% higher than the measured values. The use of silver and rhodium filters resulted in a mean simulated dose of 1.00 mGy and 0.72 mGy, respectively, while the corresponding mean measured values were 0.89 mGy ± 0.03 mGy and 0.62 mGy ± 0.02 mGy. The mean glandular dose can be reliably evaluated by comparing the simulated and measured values.
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Affiliation(s)
- Dong-Yeon Lee
- Department of Radiological Science, College of Nursing, Health Sciences and Human Ecology, Dong-Eui University, Busan, Republic of Korea
| | - Yong-In Jo
- Dongnam Institute of Radiological and Medical Sciences, Busan, Republic of Korea
| | - Sung-Hee Yang
- Department of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan, Republic of Korea
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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°.
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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
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Kim JS, Bae K, Lee EJ, Bang M. Mammography with a fully automated breast volumetric software as a novel method for estimating the preoperative breast volume prior to mastectomy. Ann Surg Treat Res 2021; 100:313-319. [PMID: 34136427 PMCID: PMC8176198 DOI: 10.4174/astr.2021.100.6.313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/22/2021] [Accepted: 04/09/2021] [Indexed: 11/30/2022] Open
Abstract
Purpose Increasing interest in maintaining a positive body image following breast cancer surgery has become an important aspect of reconstruction surgery. Volume matching of the reconstructed breast to natural breasts is the most important consideration. This study aimed to explore the feasibility of using mammography with a fully automated breast volumetric software to measure the preoperative breast volume in patients with breast cancer. Methods We evaluated patients who underwent a total mastectomy between July 2016 and February 2021. The specimen volume following total mastectomy was compared with breast volume estimates using a fully automated volumetric software (Quantra ver. 2.1.1) and 4 other previously described mammography-based prediction methods. The association between the estimates and mastectomy specimen volume was assessed using Pearson correlation and Bland-Altman analysis. Results Sixty-six patients were included. Compared with previously described mammography-based methods, Quantra estimates were more strongly correlated with mastectomy specimen volume in the entire, fatty, and dense breast groups (r = 0.920, 0.921, and 0.915, respectively; P < 0.001). In applying Quantra estimates for measuring preoperative breast volume, we adjusted a simple equation: mastectomy specimen volume = Quantra estimate × 0.8. Conclusion Mammography with a fully automated breast volumetric software can be useful for measuring preoperative breast volume in patients with breast cancer who undergo reconstruction surgery.
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Affiliation(s)
- Jin Sung Kim
- Department of Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Kyoungkyg Bae
- Department of Radiology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Eun Ji Lee
- Department of Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Minseo Bang
- Department of Radiology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
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Alves MS, Ferro AGL, Moreira MCL, Santos WS, Neves LP, Perini AP, Belinato W, Souza DN. Estimated risk of radiation-induced cancer following breast screening employing tomosynthesis and digital mammography. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:254-265. [PMID: 33498015 DOI: 10.1088/1361-6498/abdfd8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
The objective of this study was to estimate the risk of radiation-induced injury to the organs due to ionizing radiation following breast screening recommendations employing digital breast tomosynthesis (DBT) and digital mammography (DM). Using the Monte Carlo method, absorbed doses in the tissues and organs were calculated on an adult female phantom, considering two-view craniocaudal (CC) and mediolateral oblique (MLO) projections for each breast. The results showed differences in the total effective risk due to DM (CC + MLO) and DBT (CC + MLO) examinations in Brazil, ranging from 20.73 cases 10-5(DM) to 27.19 cases 10-5(DBT). Significant differences were also observed in the total effective risk of cancer incidence in the lungs due to DM (CC + MLO) and DBT (CC + MLO), ranging from 1.75×10-01cases 10-5(DM) to 1.76×10-01cases 10-5(DBT). The results indicate that the total effective risk of incidence should be considered as an additional parameter for the evaluation of DBT or DBT + DM program performance.
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Affiliation(s)
- Marcos S Alves
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
| | - Ana G L Ferro
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
| | - Márcia C L Moreira
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
| | - William S Santos
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Lucio P Neves
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Ana P Perini
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
- Programa de Pós-Graduação em Engenharia Biomédica, Faculdade de Engenharia Elétrica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Walmir Belinato
- Instituto Federal da Bahia (IFBA), Vitória da Conquista, BA, Brazil
| | - Divanizia N Souza
- Departamento de Física, Universidade Federal de Sergipe, São Cristóvão, SE, Brazil
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Ketelhut S, Büermann L, Hilgers G. Catalog of x-ray spectra of Mo-, Rh-, and W-anode-based x-ray tubes from 10 to 50 kV. Phys Med Biol 2021; 66. [PMID: 33902019 DOI: 10.1088/1361-6560/abfbb2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 04/26/2021] [Indexed: 11/11/2022]
Abstract
This work presents a comprehensive catalog of x-ray spectra measured from x-ray tubes with tungsten, molybdenum, and rhodium anodes generated at tube potentials between 10 and 50 kV in steps of 1 kV. They can serve as an input for dose calculations, image quality calculations, investigations of detector features, and validations of computational spectral models, among other things. The measurements are performed by means of a high-purity germanium detector-based spectrometer 1 m from the x-ray sources without any added filtration. The x-ray tubes are characterized by thin beryllium exit windows (0.15-4 mm); thus, for energies above 15 keV, the spectra recorded can be considered approximately unfiltered. This allows potential users of the catalog to computationally add any filter to the spectra in order to create special radiation qualities of their choice. To validate this option, a small number of spectra are recorded with filter materials in place whose purity and thickness are known with high precision. These spectra are compared to the corresponding spectra from the catalog obtained by means of computationally added filters. The two types of spectra agree extremely well. Several typical mammographic radiation qualities are selected to compare the spectra obtained from the catalog presented here with corresponding spectra obtained from other catalogs published by Booneet al(1997Med. Phys.241863-74) and Hernandezet al(2017Med. Phys.442148-60). In contrast to the work presented here, those spectra rely partly or fully on calculations. A quantitative comparison is made by means of typical x-ray quality descriptors such as the mean energy and the first and second half-value layer. The results obtained from the Boone catalog match those of the current catalog sufficiently well for the Mo- and Rh-anode-based spectra. However, significant differences up to 10 times the estimated uncertainties are found for the quality descriptors evaluated from the spectra of Hernandezet aland the W-anode based spectra of Booneet al.
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Affiliation(s)
| | - Ludwig Büermann
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
| | - Gerhard Hilgers
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
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FitzGerald P, Araujo S, Wu M, De Man B. Semiempirical, parameterized spectrum estimation for x-ray computed tomography. Med Phys 2021; 48:2199-2213. [PMID: 33426704 DOI: 10.1002/mp.14715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/10/2020] [Accepted: 12/29/2020] [Indexed: 01/06/2023] Open
Abstract
PURPOSE To develop a tool to produce accurate, well-validated x-ray spectra for standalone use or for use in an open-access x-ray/CT simulation tool. Spectrum models will be developed for tube voltages in the range of 80 kVp through 140 kVp and for anode takeoff angles in the range of 5° to 9°. METHODS Spectra were initialized based on physics models, then refined using empirical measurements, as follows. A new spectrum-parameterization method was developed, including 13 spline knots to represent the bremsstrahlung component and 4 values to represent characteristic lines. Initial spectra at 80, 100, 120, and 140 kVp and at takeoff angles from 5° to 9° were produced using physics-based spectrum estimation tools XSPECT and SpekPy. Empirical experiments were systematically designed with careful selection of attenuator materials and thicknesses, and by reducing measurement contamination from scatter to <1%. Measurements were made on a 64-row CT scanner using the scanner's detector and using multiple layers of polymethylmethacrylate (PMMA), aluminum, titanium, tin, and neodymium. Measurements were made at 80, 100, 120, and 140 kVp and covering the entire 64-row detector (takeoff angles from 5° to 9°); a total of 6,144 unique measurements were made. After accounting for the detector's energy response, parameterized representations of the initial spectra were refined for best agreement with measurements using two proposed optimization schemes: based on modulation and based on gradient descent. X-ray transmission errors were computed for measurements vs calculations using the nonoptimized and optimized spectra. Half-value, tenth-value, and hundredth-value layers for PMMA, Al, and Ti were calculated. RESULTS Spectra before and after parameterization were in excellent agreement (e.g., R2 values of 0.995 and 0.997). Empirical measurements produced smoothly varying curves with x-ray transmission covering a range of up to 3.5 orders of magnitude. Spectra from the two optimization schemes, compared with the unoptimized physic-based spectra, each improved agreement with measurements by twofold through tenfold, for both postlog transmission data and for fractional value layers. CONCLUSION The resulting well-validated spectra are appropriate for use in the open-access x-ray/CT simulator under development, the x-ray-based Cancer Imaging Toolkit (XCIST), or for standalone use. These spectra can be readily interpolated to produce spectra at arbitrary kVps over the range of 80 to 140 kVp and arbitrary takeoff angles over the range of 5° to 9°. Furthermore, interpolated spectra over these ranges can be obtained by applying the standalone Matlab function available at https://github.com/xcist/documentation/blob/master/XCISTspectrum.m.
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Affiliation(s)
| | | | - Mingye Wu
- GE Research, Niskayuna, NY, 12309, USA
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12
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Niroshani HS, Jeyasugiththan J, Senanayake G, Negishi T. Establishment of regional diagnostic reference levels for digital mammography in Western Province of Sri Lanka. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:79-96. [PMID: 33271512 DOI: 10.1088/1361-6498/abd075] [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: 09/30/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
The radiation dose to the breasts should be kept to a minimum as breast tissues are highly sensitive to radiation. In mammography, the mean glandular dose (MGD) is used to specify the patient dose. In this study, data on the MGD during diagnostic mammographic examinations was collected using the database from six digital mammography facilities available in the Western Province in Sri Lanka. Examinations involving breast pathology, breast implants, or compressed breast thicknesses (CBT) outside the range of 20-110 mm were excluded in this study. The mean MGD per breast was 3.50 mGy, with a mean CBT of 57 mm. The mean MGD per facility varies from 1.58 to 2.27 mGy, with overall 75th and 95th percentiles of 2.15 and 2.82 mGy, respectively. The 75th and 95th percentile MGD per image, for the average CBT of 57 ± 12 mm, were 2.00 and 2.65 mGy respectively. The 75th percentile value of the MGD is suggested for the Western Province and it depends on the specific CBT.
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Affiliation(s)
- H S Niroshani
- Department of Nuclear Science, University of Colombo, Colombo, Sri Lanka
- Department of Radiography & Radiotherapy, General Sir John Kotelawala Defence University, Werahera, Sri Lanka
- Department of Radiological Sciences, Graduate school of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | | | - G Senanayake
- Department of Clinical Sciences, Faculty of Medicine, General Sir John Kotelawala Defence University, Werahera, Sri Lanka
| | - Toru Negishi
- Department of Radiological Sciences, Graduate school of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
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13
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Haggmark I, Shaker K, Hertz HM. In Silico Phase-Contrast X-Ray Imaging of Anthropomorphic Voxel-Based Phantoms. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:539-548. [PMID: 33055024 DOI: 10.1109/tmi.2020.3031318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Propagation-based phase-contrast X-ray imaging is an emerging technique that can improve dose efficiency in clinical imaging. In silico tools are key to understanding the fundamental imaging mechanisms and develop new applications. Here, due to the coherent nature of the phase-contrast effects, tools based on wave propagation (WP) are preferred over Monte Carlo (MC) based methods. WP simulations require very high wave-front sampling which typically limits simulations to small idealized objects. Virtual anthropomorphic voxel-based phantoms are typically provided with a resolution lower than imposed sampling requirements and, thus, cannot be directly translated for use in WP simulations. In the present paper we propose a general strategy to enable the use of these phantoms for WP simulations. The strategy is based on upsampling in the 3D domain followed by projection resulting in high-resolution maps of the projected thickness for each phantom material. These maps can then be efficiently used for simulations of Fresnel diffraction to generate in silico phase-contrast X-ray images. We demonstrate the strategy on an anthropomorphic breast phantom to simulate propagation-based phase-contrast mammography using a laboratory micro-focus X-ray source.
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14
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Michielsen K, Rodríguez-Ruiz A, Reiser I, Nagy JG, Sechopoulos I. Iodine quantification in limited angle tomography. Med Phys 2020; 47:4906-4916. [PMID: 32803800 PMCID: PMC7689880 DOI: 10.1002/mp.14400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/06/2020] [Indexed: 11/08/2022] Open
Abstract
Purpose To develop and test the feasibility of a two‐pass iterative reconstruction algorithm with material decomposition designed to obtain quantitative iodine measurements in digital breast tomosynthesis. Methods Contrast‐enhanced mammography has shown promise as a cost‐effective alternative to magnetic resonance imaging for imaging breast cancer, especially in dense breasts. However, one limitation is the poor quantification of iodine contrast since the true three‐dimensional lesion shape cannot be inferred from the two‐dimensional (2D) projection. Use of limited angle tomography can potentially overcome this limitation by segmenting the iodine map generated by the first‐pass reconstruction using a convolutional neural network, and using this segmentation to restrict the iodine distribution in the second pass of the reconstruction. To evaluate the performance of the algorithms, a set of 2D digital breast phantoms containing targets with varying iodine concentration was used. In each breast phantom, a single simulated lesion with a random size (4 to 8 mm) was placed in a random location within each phantom, with the iodine distribution defined as either homogeneous or rim‐enhanced and blood iodine concentration set between 1.4 and 5.6 mg/mL. Limited angle projection data of these phantoms were simulated for wide and narrow angle geometries, and the proposed reconstruction and segmentation algorithms were applied. Results The median Dice similarity coefficient of the segmented masks was 0.975 for the wide angle data and 0.926 for the narrow angle data. Using these segmentations during the second reconstruction pass resulted in an improvement in the concentration estimates (mean estimated‐to‐true concentration ratio, before and after second pass: 48% to 73% for wide angle; 30% to 73% for narrow angle), and a reduction in the coefficient of variation of the estimates (55% to 27% for wide angle; 54% to 35% for narrow angle). Conclusion We demonstrate that the proposed two‐pass reconstruction can potentially improve accuracy and precision of iodine quantification in contrast‐enhanced tomosynthesis.
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Affiliation(s)
- Koen Michielsen
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Alejandro Rodríguez-Ruiz
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Ingrid Reiser
- Department of Radiology, The University of Chicago, Chicago, IL, 60637, USA
| | - James G Nagy
- Department of Mathematics and Computer Science, Emory University, Atlanta, GA, 30322, USA
| | - Ioannis Sechopoulos
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands.,Dutch Expert Center for Screening (LRCB), Nijmegen, 6538 SW, The Netherlands
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15
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Storm C, Harvey A, Djukelic M. Mammography diagnostic reference levels in Western Australia. Phys Eng Sci Med 2020; 43:1125-1129. [PMID: 32757165 DOI: 10.1007/s13246-020-00914-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/22/2020] [Accepted: 07/30/2020] [Indexed: 12/24/2022]
Abstract
Mammography dose data has been collected from Western Australian units to establish Diagnostic Reference Levels for the state. Reference levels have been determined for a variety of phantom thicknesses for both full field digital mammography units and digital breast tomosynthesis units. Levels for the American College of Radiology (ACR) Phantom have been established as 1.3 mGy and 1.5 mGy mean glandular dose for full field digital mammography and digital breast tomosynthesis respectively. 2 cm PMMA was 0.9 mGy and 1.0 mGy and 6 cm PMMA had values of 2.0 mGy and 2.3 mGy. This data can be utilised to help establish national reference levels in the future.
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Affiliation(s)
- Cameron Storm
- Medical Technology & Physics, Sir Charles Gairdner Hospital, Perth, WA, Australia.
| | - Alicia Harvey
- Medical Technology & Physics, Sir Charles Gairdner Hospital, Perth, WA, Australia
| | - Mario Djukelic
- Medical Technology & Physics, Sir Charles Gairdner Hospital, Perth, WA, Australia
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16
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Abadi E, Segars WP, Tsui BMW, Kinahan PE, Bottenus N, Frangi AF, Maidment A, Lo J, Samei E. Virtual clinical trials in medical imaging: a review. J Med Imaging (Bellingham) 2020; 7:042805. [PMID: 32313817 PMCID: PMC7148435 DOI: 10.1117/1.jmi.7.4.042805] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 03/23/2020] [Indexed: 12/13/2022] Open
Abstract
The accelerating complexity and variety of medical imaging devices and methods have outpaced the ability to evaluate and optimize their design and clinical use. This is a significant and increasing challenge for both scientific investigations and clinical applications. Evaluations would ideally be done using clinical imaging trials. These experiments, however, are often not practical due to ethical limitations, expense, time requirements, or lack of ground truth. Virtual clinical trials (VCTs) (also known as in silico imaging trials or virtual imaging trials) offer an alternative means to efficiently evaluate medical imaging technologies virtually. They do so by simulating the patients, imaging systems, and interpreters. The field of VCTs has been constantly advanced over the past decades in multiple areas. We summarize the major developments and current status of the field of VCTs in medical imaging. We review the core components of a VCT: computational phantoms, simulators of different imaging modalities, and interpretation models. We also highlight some of the applications of VCTs across various imaging modalities.
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Affiliation(s)
- Ehsan Abadi
- Duke University, Department of Radiology, Durham, North Carolina, United States
| | - William P. Segars
- Duke University, Department of Radiology, Durham, North Carolina, United States
| | - Benjamin M. W. Tsui
- Johns Hopkins University, Department of Radiology, Baltimore, Maryland, United States
| | - Paul E. Kinahan
- University of Washington, Department of Radiology, Seattle, Washington, United States
| | - Nick Bottenus
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
- University of Colorado Boulder, Department of Mechanical Engineering, Boulder, Colorado, United States
| | - Alejandro F. Frangi
- University of Leeds, School of Computing, Leeds, United Kingdom
- University of Leeds, School of Medicine, Leeds, United Kingdom
| | - Andrew Maidment
- University of Pennsylvania, Department of Radiology, Philadelphia, Pennsylvania, United States
| | - Joseph Lo
- Duke University, Department of Radiology, Durham, North Carolina, United States
| | - Ehsan Samei
- Duke University, Department of Radiology, Durham, North Carolina, United States
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17
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Vassiliev ON, Peterson CB, Grosshans DR, Mohan R. A simple model for calculating relative biological effectiveness of X-rays and gamma radiation in cell survival. Br J Radiol 2020; 93:20190949. [PMID: 32464080 DOI: 10.1259/bjr.20190949] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES The relative biological effectiveness (RBE) of X-rays and γ radiation increases substantially with decreasing beam energy. This trend affects the efficacy of medical applications of this type of radiation. This study was designed to develop a model based on a survey of experimental data that can reliably predict this trend. METHODS In our model, parameters α and β of a cell survival curve are simple functions of the frequency-average linear energy transfer (LF) of delta electrons. The choice of these functions was guided by a microdosimetry-based model. We calculated LF by using an innovative algorithm in which LF is associated with only those electrons that reach a sensitive-to-radiation volume (SV) within the cell. We determined model parameters by fitting the model to 139 measured (α,β) pairs. RESULTS We tested nine versions of the model. The best agreement was achieved with [Formula: see text] and β being linear functions of [Formula: see text] .The estimated SV diameter was 0.1-1 µm. We also found that α, β, and the α/β ratio increased with increasing [Formula: see text] . CONCLUSIONS By combining an innovative method for calculating [Formula: see text] with a microdosimetric model, we developed a model that is consistent with extensive experimental data involving photon energies from 0.27 keV to 1.25 MeV. ADVANCES IN KNOWLEDGE We have developed a photon RBE model applicable to an energy range from ultra-soft X-rays to megaelectron volt γ radiation, including high-dose levels where the RBE cannot be calculated as the ratio of α values. In this model, the ionization density represented by [Formula: see text] determines the RBE for a given photon spectrum.
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Affiliation(s)
- Oleg N Vassiliev
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Christine B Peterson
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - David R Grosshans
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Radhe Mohan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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18
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Vancoillie L, Marshall N, Cockmartin L, Vignero J, Zhang G, Bosmans H. Verification of the accuracy of a hybrid breast imaging simulation framework for virtual clinical trial applications. J Med Imaging (Bellingham) 2020; 7:042804. [PMID: 32341939 DOI: 10.1117/1.jmi.7.4.042804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 04/06/2020] [Indexed: 11/14/2022] Open
Abstract
Purpose: The impact of system parameters on signal detectability can be studied with simulation platforms. We describe the steps taken to verify and confirm the accuracy of a local platform developed for the use in virtual clinical trials. Approach: The platform simulates specific targets into existing two-dimensional full-field digital mammography and digital breast tomosynthesis images acquired on a Siemens Inspiration system. There are three steps: (1) creation of voxel models or analytical objects; (2) generation of a realistic object template with accurate resolution, scatter, and noise properties; and (3) insertion and reconstruction. Four objects were simulated: a 0.5-mm aluminium (Al) sphere and a 0.2-mm-thick Al sheet in a PMMA stack, a 0.8-mm steel edge and a three-dimensional mass model in a structured background phantom. Simulated results were compared to acquired data. Results: Peak contrast and signal difference-to-noise ratio (SDNR) were in close agreement ( < 5 % error) for both sphere and sheet. The similarity of pixel value profiles for sphere and sheet in the x y direction and the artifact spread function for real and simulated spheres confirmed accurate geometric modeling. Absolute and relative average deviation between modulation transfer function measured from a real and simulated edges showed accurate sharpness modelling for spatial frequencies up to the Nyquist frequency. Real and simulated objects could not be differentiated visually. Conclusions: The results indicate that this simulation framework is a strong candidate for use in virtual clinical studies.
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Affiliation(s)
- Liesbeth Vancoillie
- KU Leuven, Division of Medical Physics and Quality Assessment, Department of Imaging and Pathology, Leuven, Belgium
| | - Nicholas Marshall
- KU Leuven, Division of Medical Physics and Quality Assessment, Department of Imaging and Pathology, Leuven, Belgium.,UZ Leuven, Department of Radiology, Leuven, Belgium
| | | | | | - Guozhi Zhang
- UZ Leuven, Department of Radiology, Leuven, Belgium
| | - Hilde Bosmans
- KU Leuven, Division of Medical Physics and Quality Assessment, Department of Imaging and Pathology, Leuven, Belgium.,UZ Leuven, Department of Radiology, Leuven, Belgium
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Chusin T, Matsubara K, Takemura A, Okubo R, Ogawa Y. Validation of mammographic x-ray spectra generated using Particle and Heavy Ion Transport code System. Phys Med Biol 2020; 65:065004. [PMID: 32187021 DOI: 10.1088/1361-6560/ab735c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A Monte Carlo (MC) code is a robust method to generate a mammographic x-ray spectrum because the geometry of a mammography system can be flexible and directly modeled in MC simulation. However, simulations from MC code need to be validated before it can be reliably used for specific applications. This study aimed to generate and validate the x-ray spectra of relevant anodes used in mammography and breast tomosynthesis using Particle and Heavy Ion Transport code System (PHITS). PHITS version 3.08 was used to generate the x-ray spectra of molybdenum (Mo), rhodium (Rh), and tungsten (W) anodes. The Mo anode spectrum derived using PHITS was compared with those obtained using other MC codes. The generated spectra of all anodes were compared with the literature. Parameters including spectral shape, K characteristic x-ray yield, heel effect, and half-value layer (HVL) were used for a comparative assessment. The differences in these assessment parameters conducted by PHITS and PHITSEGS5 simulations were studied. Regarding the comparative parameters, PHITSEGS5 simulation improved the accuracy of mammographic x-ray generation compared to PHITS simulation; K x-ray and bremsstrahlung yields of the Mo anode spectrum generated by PHITSEGS5 simulation were a better agreement with those generated by other MC code simulations. The PHITSEGS5 spectra overestimated K x-ray and low-energy bremsstrahlung photons in comparison with measured spectra. Subsequently, HVLs calculated from PHITSEGS5 spectra were 1.0% (Mo/Mo) and 7.0% (W/Al) lower than those derived from measured spectra. For Mo and Rh anodes, relative difference of HVLs calculated from PHITSEGS5 spectra and those obtained from literature and measurement were within the TRS 457 acceptance criteria (±0.02 mm Al). The observed difference exceeded the acceptance criteria for W anode. Regarding existed consistency in HVL between simulation and measurement, PHITSEGS5 simulation can be reliably used to generate x-ray spectra of Mo and Rh anodes. However, its accuracy should be improved for generating W anode spectrum.
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Affiliation(s)
- Thunyarat Chusin
- Department of Quantum Medical Technology, Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan. Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phitsanulok, Thailand
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20
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Barufaldi B, Zuckerman SP, Medeiros RB, Maidment AD, Schiabel H. Characterization of the imaging settings in screening mammography using a tracking and reporting system: A multi-center and multi-vendor analysis. Phys Med 2020; 71:137-149. [PMID: 32143121 PMCID: PMC7187399 DOI: 10.1016/j.ejmp.2020.02.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 02/07/2020] [Accepted: 02/22/2020] [Indexed: 10/24/2022] Open
Abstract
A tracking and reporting system was developed to monitor radiation dose in X-ray breast imaging. We used our tracking system to characterize and compare the mammographic practices of five breast imaging centers located in the United States and Brazil. Clinical data were acquired using eight mammography systems comprising three modalities: computed radiography (CR), full-field digital mammography (FFDM), and digital breast tomosynthesis (DBT). Our database consists of metadata extracted from 334,234 images. We analyzed distributions and correlations of compressed breast thickness (CBT), compression force, target-filter combinations, X-ray tube voltage, and average glandular dose (AGD). AGD reference curves were calculated based on AGD distributions as a function of CBT. These curves represent an AGD reference for a particular population and system. Differences in AGD and imaging settings were attributed to a combination of factors, such as improvements in technology, imaging protocol, and patient demographics. The tracking system allows the comparison of various imaging settings used in screening mammography, as well as the tracking of patient- and population-specific breast data collected from different populations.
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Affiliation(s)
- Bruno Barufaldi
- University of Pennsylvania, Department of Radiology, 3620 Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Samantha P Zuckerman
- University of Pennsylvania, Department of Radiology, 3620 Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Regina B Medeiros
- Federal University of Sao Paulo, Escola Paulista de Medicina, 740 Rua Botucatu, Sao Paulo, SP 04023-062, Brazil
| | - Andrew D Maidment
- University of Pennsylvania, Department of Radiology, 3620 Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Homero Schiabel
- University of Sao Paulo, Department of Electrical Engineering, 400 Trabalhador Sao-Carlense, Sao Carlos, SP 13566-590, Brazil.
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21
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Chang TY, Lai KJ, Tu CY, Wu J. Three-layer heterogeneous mammographic phantoms for Monte Carlo simulation of normalized glandular dose coefficients in mammography. Sci Rep 2020; 10:2234. [PMID: 32042071 PMCID: PMC7010737 DOI: 10.1038/s41598-020-59317-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 01/27/2020] [Indexed: 12/15/2022] Open
Abstract
Normalized glandular dose (DgN) coefficients obtained using homogeneous breast phantoms are commonly used in breast dosimetry for mammography. However, glandular tissue is heterogeneously distributed in the breast. This study aimed to construct three-layer heterogeneous mammographic phantoms (THEPs) to examine the effect of glandular distribution on DgN coefficient. Each layer of THEPs was set to 25%, 50%, or 75% glandular fraction to emulate heterogeneous glandular distribution. Monte Carlo simulation was performed to attain mean glandular dose (MGD) and air kerma at 22-36 kVp and W/Al, W/Rh, and W/Ag target-filter combinations. The heterogeneous DgN coefficient was calculated as functions of the mean glandular fraction (MGF), breast thickness, tube voltage, and half-value layer. At 50% MGF, the heterogeneous DgN coefficients for W/Al, W/Rh, and W/Ag differed by 40.3%, 36.7%, and 31.2%. At 9-cm breast thickness, the DgN values of superior and inferior glandular distributions were 25.4% higher and 29.2% lower than those of uniform distribution. The proposed THEPs can be integrated with conventional breast dosimetry to consider the heterogeneous glandular distribution in clinical practice.
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Affiliation(s)
- Tien-Yu Chang
- Department of Radiology, Cheng Hsin General Hospital, Taipei, Taiwan
| | - Kuan-Jen Lai
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Chun-Yuan Tu
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
- Department of Radiology, Mackay Memorial Hospital, Taipei, Taiwan
| | - Jay Wu
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
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22
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Diaz O, Elangovan P, Young KC, Wells K, Dance DR. Simple method for computing scattered radiation in breast tomosynthesis. Med Phys 2019; 46:4826-4836. [PMID: 31410861 DOI: 10.1002/mp.13760] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 01/15/2023] Open
Abstract
PURPOSE Virtual clinical trials (VCT) are a powerful imaging tool that can be used to investigate digital breast tomosynthesis (DBT) technology. In this work, a fast and simple method is proposed to estimate the two-dimensional distribution of scattered radiation which is needed when simulating DBT geometries in VCTs. METHODS Monte Carlo simulations are used to precalculate scatter-to-primary ratio (SPR) for a range of low-resolution homogeneous phantoms. The resulting values can be used to estimate the two-dimensional (2D) distribution of scattered radiation arising from inhomogeneous anthropomorphic phantoms used in VCTs. The method has been validated by comparing the values of the scatter thus obtained against the results of direct Monte Carlo simulation for three different types of inhomogeneous anthropomorphic phantoms. RESULTS Differences between the proposed scatter field estimation method and the ground truth data for the OPTIMAM phantom had an average modulus and standard deviation of over the projected breast area of 2.4 ± 0.9% (minimum -17.0%, maximum 27.7%). The corresponding values for the University of Pennsylvania and Duke University breast phantoms were 1.8 ± 0.1% (minimum -8.7%, maximum 8.0%) and 5.1 ± 0.1% (minimum -16.2%, maximum 7.4%), respectively. CONCLUSIONS The proposed method, which has been validated using three of the most common breast models, is a useful tool for accurately estimating scattered radiation in VCT schemes used to study current designs of DBT system.
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Affiliation(s)
- Oliver Diaz
- CVSSP, University of Surrey, Guildford, GU2 7XH, UK
- VICOROB, University of Girona, Girona, 17071, Spain
| | | | - Kenneth C Young
- NCCPM, Royal Surrey County Hospital, Guildford, GU2 7XX, UK
- Department of Physics, University of Surrey, Guildford, GU2 7XH, UK
| | - Kevin Wells
- CVSSP, University of Surrey, Guildford, GU2 7XH, UK
| | - David R Dance
- NCCPM, Royal Surrey County Hospital, Guildford, GU2 7XX, UK
- Department of Physics, University of Surrey, Guildford, GU2 7XH, UK
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23
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Tanguay J, Lalonde R, Bjarnason TA, Yang CYJ. Cascaded systems analysis of anatomic noise in digital mammography and dual-energy digital mammography. Phys Med Biol 2019; 64:215002. [PMID: 31470440 DOI: 10.1088/1361-6560/ab3fcd] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In x-ray based imaging of the breast, contrast between fibroglandular (Fg) tissue and adipose (Ad) tissue is a source of anatomic noise. The goal of this work was to validate by simulation and experiment a mathematical framework for modelling the Fg component of anatomic noise in digital mammograpy (DM) and dual-energy (DE) DM. Our mathematical framework unifies and generalizes existing approaches. We compared mathematical predictions directly with empirical measurements of the anatomic noise power spectrum of the CIRS BR3D structured breast phantom using two clinical mammography systems and four beam qualities. Our simulation and experimental results showed agreement with mathematical predictions. As a demonstration of utility, we used our mathematical framework in a theoretical spectral optimization of DM for the task of detecting breast masses. Our theoretical optimization showed that the optimal tube voltage for DM may be higher than that based on predictions that do not account for anatomic noise, in agreement with recent theoretical findings. Additionally, our theoretical optimization predicts that filtering tungsten-anode x-ray spectra with rhodium has little influence on lesion detectability, in contrast with previous findings. The mathematical methods validated in this work can be incorporated easily into cascaded systems analysis of breast imaging systems and will be useful when optimizating novel techniques for x-ray-based imaging of the breast.
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Affiliation(s)
- Jesse Tanguay
- Department of Physics, Ryerson University, Toronto, Ontario, Canada. Author to whom correspondence should be addressed
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Sarno A, Tucciariello RM, Mettivier G, di Franco F, Russo P. Monte Carlo calculation of monoenergetic and polyenergetic DgN coefficients for mean glandular dose estimates in mammography using a homogeneous breast model. ACTA ACUST UNITED AC 2019; 64:125012. [DOI: 10.1088/1361-6560/ab253f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Kretz T, Anton M, Schaeffter T, Elster C. Determination of contrast-detail curves in mammography image quality assessment by a parametric model observer. Phys Med 2019; 62:120-128. [PMID: 31153391 DOI: 10.1016/j.ejmp.2019.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 04/26/2019] [Accepted: 05/12/2019] [Indexed: 12/01/2022] Open
Abstract
A novel approach is proposed for the determination of contrast-detail curves in mammography image quality assessment. The approach is compared with current practice using virtual mammography. A binary parametric model observer is applied to images of the CDMAM phantom. The observer accounts for the simple disc shaped objects in the phantom and is applied separately to each cell of the phantom. For each of these applications, the area under the ROC curve (AUC) of the model observer is determined. The different AUCs, calculated from different applications of the parametric model observer, are then combined to a single contrast-detail curve quantifying the ability of the observer to detect details in the images. Virtual mammography is developed as a tool to simulate X-ray images of single CDMAM cells and to quantitatively assess the approach in comparison with current practice. It is shown that the proposed approach can lead to similar contrast-detail curves as current practice. The precision of the estimated contrast-detail curves is increased, i.e. using 5 images yields about the same precision for the proposed approach as 16 images when applying current practice. We conclude that contrast-detail curves in mammography image quality assessment can also be determined through the AUC of a binary parametric model observer. Since the proposed approach has higher precision than current practice, it is a promising candidate for contrast-detail analysis in mammography image quality assessment.
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Affiliation(s)
- T Kretz
- Physikalisch-Technische Bundesanstalt, Braunschweig and Berlin, Germany.
| | - M Anton
- Physikalisch-Technische Bundesanstalt, Braunschweig and Berlin, Germany
| | - T Schaeffter
- Physikalisch-Technische Bundesanstalt, Braunschweig and Berlin, Germany
| | - C Elster
- Physikalisch-Technische Bundesanstalt, Braunschweig and Berlin, Germany
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Wang J, Chen L, Persson M, Rajbhandary PL, Kandlakunta P, Carini G, Fahrig R. Pulse pileup analysis for a double-sided silicon strip detector using variable pulse shapes. IEEE TRANSACTIONS ON NUCLEAR SCIENCE 2019; 66:960-968. [PMID: 31327872 PMCID: PMC6640861 DOI: 10.1109/tns.2019.2917144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Due to pulse pileup, photon counting detectors (PCDs) suffer from count loss and energy distortion when operating in high count rate environments. In this paper, we studied the pulse pileup of a double-sided silicon strip detector (DSSSD) to evaluate its potential application in a mammography system. We analyzed the pulse pileup using pulses of varied shapes, where the shape of the pulse depends on the location of photon interaction within the detector. To obtain the shaped pulses, first, transient currents for photons interacting at different locations were simulated using a Technology Computer-Aided Design (TCAD) software. Next, the currents were shaped by a CR-RC2 shaping circuit, calculated using Simulink. After obtaining these pulses, both the different orders of pileup and the energy spectrum were calculated by taking into account the following two factors: 1) spatial distribution of photon interactions within the detector, and 2) time interval distribution between successive photons under a given photon flux. We found that for a DSSSD with thickness of 300 μm, pitch of 25 μm and strip length of 1 cm, under a bias voltage of 50 V, the variable pulse shape model predicts the fraction free of pileup can be > 90 % under a photon flux of 3.75 Mcps/mm2. The double-sided silicon-strip detector is a promising candidate for digital mammography applications.
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Affiliation(s)
- Jinghui Wang
- J. Wang was with the Department of Radiology, Stanford University, Stanford, CA 94305 USA. He is now with the Department of Radiation Oncology, Stanford University, Stanford, CA 94305 USA
| | - Linchuan Chen
- L. Chen was with the Department of Computer Science and Engineering, The Ohio State University, Columbus OH 43210 USA. He is now with Google, 1600 Amphitheatre Parkway, Mountain View, CA 94043 USA
| | - Mats Persson
- M. Persson is with the Department of Bioengineering, Stanford University, Stanford, California 94305 USA
| | - Paurakh L Rajbhandary
- P. L. Rajbhandary was with Department of Bioengineering, Stanford University, Stanford, CA 94305 USA
| | - Praneeth Kandlakunta
- P. Kandlakunta is with the Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 USA
| | - Gabriella Carini
- G. Carini was with the SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA. She is now with the Brookhaven National Laboratory, Upton, NY 11973 USA
| | - Rebecca Fahrig
- R. Fahrig was with the Department of Radiology, Stanford University, Stanford, CA 94305 USA. She is now with Siemens Healthcare GmbH, Erlangen, 91052 Germany, also with Pattern Recognition Lab, Friedrich-Alexander-University, Erlangen-Nuremberg, 91052 Germany
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Breast MRI and X-ray mammography registration using gradient values. Med Image Anal 2019; 54:76-87. [DOI: 10.1016/j.media.2019.02.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 02/21/2019] [Accepted: 02/22/2019] [Indexed: 11/21/2022]
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Baptista M, Di Maria S, Vieira S, Santos J, Pereira J, Pereira M, Vaz P. Dosimetric assessment of the exposure of radiotherapy patients due to cone-beam CT procedures. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2019; 58:21-37. [PMID: 30392077 DOI: 10.1007/s00411-018-0760-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 10/30/2018] [Indexed: 06/08/2023]
Abstract
Cone-beam computed tomography (CBCT) is widely used for pre-treatment verification and patient setup in image-guided radiation therapy (IGRT). CBCT imaging is employed daily and several times per patient, resulting in potentially high cumulative imaging doses to healthy tissues that surround exposed target organs. Computed tomography dose index (CTDI) is the parameter used by CBCT equipment as indication of the radiation output to patients. This study aimed to increase the knowledge on the relation between CBCT organ doses and weighted CTDI (CTDIW) for a thorax scanning protocol. A CBCT system was modelled using the Monte Carlo (MC) radiation transport program MCNPX2.7.0. Simulation results were validated against half-value layer (HVL), axial beam profile, patient skin dose (PSD) and CTDI measurements. For organ dose calculations, a male voxel phantom ("Golem") was implemented with the CBCT scanner computational model. After a successful MC model validation with measurements, a systematic comparison was performed between organ doses (and their distribution) and CTDI dosimetry concepts [CTDIW and cumulative dose quantities f100(150) and [Formula: see text]]. The results obtained show that CBCT organ doses vary between 1.2 ± 0.1 mGy and 3.3 ± 0.2 mGy for organs located within the primary beam. It was also verified that CTDIW allows prediction of absorbed doses to tissues at distances of about 5 cm from the isocentre of the CBCT system, whereas f100(150) allows prediction of organ doses at distances of about 10 cm from the isocentre, independently from its location. This study demonstrates that these dosimetric concepts are suitable methods that easily allow a good approximation of the additional CBCT imaging doses during a typical lung cancer IGRT treatment.
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Affiliation(s)
- Mariana Baptista
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal.
| | - Salvatore Di Maria
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Sandra Vieira
- Fundação Champalimaud, Centro Clínico Champalimaud, Avenida de Brasília, 1400-038, Lisbon, Portugal
| | - Joana Santos
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Instituto Politécnico de Coimbra, ESTESC, DIMR, Rua 5 de Outubro, 3046-854, Coimbra, Portugal
| | - Joana Pereira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Laboratório de Protecção e Segurança Radiológica, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Miguel Pereira
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
- Laboratório de Protecção e Segurança Radiológica, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
| | - Pedro Vaz
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Estrada Nacional 10, km 139,7, 2695-066, Bobadela LRS, Portugal
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Huang H, Scaduto DA, Liu C, Yang J, Zhu C, Rinaldi K, Eisenberg J, Liu J, Hoernig M, Wicklein J, Vogt S, Mertelmeier T, Fisher PR, Zhao W. Comparison of contrast-enhanced digital mammography and contrast-enhanced digital breast tomosynthesis for lesion assessment. J Med Imaging (Bellingham) 2019; 6:031407. [PMID: 30766895 DOI: 10.1117/1.jmi.6.3.031407] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/10/2019] [Indexed: 01/22/2023] Open
Abstract
Contrast-enhanced digital mammography (CEDM) reveals neovasculature of breast lesions in a two-dimensional contrast enhancement map. Contrast-enhanced digital breast tomosynthesis (CEDBT) provides contrast enhancement in three dimensions, which may improve lesion characterization and localization. We aim to compare CEDM and CEDBT for lesion assessment. Women with breast imaging-reporting and data system 4 or 5 suspicious breast lesion(s) were recruited in our study and were imaged with CEDM and CEDBT in succession under one breast compression. Two radiologists assessed CEDM and CEDBT with both images displayed side-by-side and compared (1) contrast enhancement of lesions and (2) lesion margin using a five-point scale ranging from - 2 (CEDM much better) to + 2 (CEDBT much better). Biopsy identified 19 malignant lesions with contrast enhancement. Our results show that CEDBT provides better lesion margins than CEDM with limited reduction in contrast enhancement. CEDBT delivers less radiation dose compared to CEDM + DBT. Synthetic CEDM can be generated from CEDBT data and provides lesion contrast enhancement comparable to CEDM. CEDBT has potential for clinical applications, such as treatment response monitoring and guidance for biopsy.
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Affiliation(s)
- Hailiang Huang
- Stony Brook Medicine, Department of Radiology, Stony Brook, New York, United States
| | - David A Scaduto
- Stony Brook Medicine, Department of Radiology, Stony Brook, New York, United States
| | - Chunling Liu
- Stony Brook Medicine, Department of Radiology, Stony Brook, New York, United States
| | - Jie Yang
- Stony Brook Medicine, Department of Family, Population and Preventive Medicine, Stony Brook, New York, United States
| | - Chencan Zhu
- Stony Brook University, Department of Applied Mathematics and Statistics, Stony Brook, New York, United States
| | - Kim Rinaldi
- Stony Brook Medicine, Department of Radiology, Stony Brook, New York, United States
| | - Jason Eisenberg
- Stony Brook Medicine, Department of Radiology, Stony Brook, New York, United States
| | - Jingxuan Liu
- Stony Brook Medicine, Department of Pathology, Stony Brook, New York, United States
| | | | | | - Sebastian Vogt
- Siemens Medical Solutions USA Inc., Monument, Colorado, United States
| | | | - Paul R Fisher
- Stony Brook Medicine, Department of Radiology, Stony Brook, New York, United States
| | - Wei Zhao
- Stony Brook Medicine, Department of Radiology, Stony Brook, New York, United States
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Boigné E, Muhunthan P, Mohaddes D, Wang Q, Sobhani S, Hinshaw W, Ihme M. X-ray Computed Tomography for Flame-Structure Analysis of Laminar Premixed Flames. COMBUSTION AND FLAME 2019; 200:142-154. [PMID: 30532316 PMCID: PMC6278941 DOI: 10.1016/j.combustflame.2018.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Quantitative X-ray computed tomography (XCT) diagnostics for reacting flows are developed and demonstrated in application to premixed flames in open and optically inaccessible geometries. A laboratory X-ray scanner is employed to investigate methane/air flames that were diluted with krypton as an inert radiodense tracer gas. Effects of acquisition rate and tracer gas concentration on the signal-to-noise ratio are examined. It is shown that statistically converged three-dimensional attenuation measurements can be obtained with limited impact from the tracer gas and within an acceptable acquisition time. Specific aspects of the tomographic reconstruction and the experimental procedure are examined, with particular emphasis on the quantification of experimental uncertainties. A method is developed to determine density and temperature from the X-ray attenuation measurements. These experiments are complemented by one- and multi-dimensional calculations to quantify the influence of krypton on the flame behavior. To demonstrate the merit of XCT for optically inaccessible flames, measurements of a complex flame geometry in a tubular confinement are performed. The use of a coflow to provide a uniform tracer-gas concentration is shown to improve the quantitative temperature evaluation. These measurements demonstrate the viability of XCT for flame-structure analysis and multi-dimensional temperature measurements using laboratory X-ray systems. Further opportunities for improving this diagnostic are discussed.
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Affiliation(s)
- Emeric Boigné
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Priyanka Muhunthan
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Danyal Mohaddes
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Qing Wang
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Sadaf Sobhani
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Waldo Hinshaw
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - Matthias Ihme
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
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Ghammraoui B, Makeev A, Zidan A, Alayoubi A, Glick SJ. Classification of breast microcalcifications using dual-energy mammography. J Med Imaging (Bellingham) 2019; 6:013502. [PMID: 30891465 PMCID: PMC6411940 DOI: 10.1117/1.jmi.6.1.013502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 02/19/2019] [Indexed: 11/14/2022] Open
Abstract
The potential of dual-energy mammography for microcalcification classification was investigated with simulation and phantom studies. Classification of type I/II calcifications was performed using the tissue attenuation ratio as a performance metric. The simulation and phantom studies were carried out using breast phantoms of 50% fibroglandular and 50% adipose tissue composition and thicknessess ranging from 3 to 6 cm. The phantoms included models of microcalcifications ranging in size between 200 and 900 μ m . The simulation study was carried out with fixed MGD of 1.5 mGy using various low- and high-kVp spectra, aluminum filtration thicknesses, and exposure distribution ratios to predict an optimized imaging protocol for the phantom study. Attenuation ratio values were calculated for microcalcification signals of different types at two different voltage settings. ROC analysis showed that classification performance as indicated by the area under the ROC curve was always greater than 0.95 for 1.5 mGy deposited mean glandular dose. This study provides encouraging first results in classifying malignant and benign microcalcifications based solely on dual-energy mammography images.
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Affiliation(s)
- Bahaa Ghammraoui
- U.S. Food and Drug Administration, CDRH, Division of Imaging Diagnostics and Software Reliability, Silver Spring, Maryland, United States
| | - Andrey Makeev
- U.S. Food and Drug Administration, CDRH, Division of Imaging Diagnostics and Software Reliability, Silver Spring, Maryland, United States
| | - Ahmed Zidan
- CDER, Division of Product Quality Research, Office of testing and Research, Silver Spring, Maryland, United States
| | - Alaadin Alayoubi
- CDER, Division of Product Quality Research, Office of testing and Research, Silver Spring, Maryland, United States
| | - Stephen J. Glick
- U.S. Food and Drug Administration, CDRH, Division of Imaging Diagnostics and Software Reliability, Silver Spring, Maryland, United States
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Normalized glandular dose coefficients in mammography, digital breast tomosynthesis and dedicated breast CT. Phys Med 2018; 55:142-148. [DOI: 10.1016/j.ejmp.2018.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/03/2018] [Accepted: 09/10/2018] [Indexed: 12/15/2022] Open
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Wang W, Qiu R, Ren L, Feng Z, Wu Z, Li C, Niu Y, Li J. DOSE DISTRIBUTION IN A BREAST UNDERGOING MAMMOGRAPHY BASED ON A 3D DETAILED BREAST MODEL FOR CHINESE WOMEN. RADIATION PROTECTION DOSIMETRY 2018; 181:221-228. [PMID: 29438509 DOI: 10.1093/rpd/ncy017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 01/21/2018] [Indexed: 06/08/2023]
Abstract
Not only the mean glandular dose (MGD) but also the glandular dose distribution is important in describing the radiation exposure to breast in mammography. For a more precise knowledge of the absorbed dose distribution in the breast, experimental measurements with thermoluminescence dosemeter and Monte Carlo simulations with Geant4 were performed in this study. The experimental measurements with homogeneous physical breast phantoms were used to validate Monte Carlo simulations of homogeneous mathematical breast models undergoing mammography. Then a 3D detailed breast model with a compressed breast thickness of 4 cm and a glandular content of 50%, which has been constructed in previous work, was used to study the absorbed dose distribution inside the breast undergoing mammography. Furthermore, the effects of the glandular tissue distribution on MGD were studied by reversing the breast model in head-toe direction to get a breast model with a different distribution of glandular tissues.
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Affiliation(s)
- Wenjing Wang
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Rui Qiu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Li Ren
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Zechen Feng
- Beijing Centre for Diseases Prevention and Control, Beijing, China
| | - Zhen Wu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Nuctech Company Limited, Beijing, China
| | - Chunyan Li
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Nuctech Company Limited, Beijing, China
| | - Yantao Niu
- Beijing Tongren Hospital, Captial Medical University, Beijing, China
| | - Junli Li
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
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Haba T, Koyama S, Otani N. Accuracy validation of incident photon fluence on detective quantum efficiency in mammography. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2018; 41:847-852. [PMID: 30151709 DOI: 10.1007/s13246-018-0679-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 08/20/2018] [Indexed: 10/28/2022]
Abstract
X-ray image evaluation is commonly performed by determining the detective quantum efficiency (DQE). DQE is calculated with a presampled modulation transfer function (MTF), incident photon fluence, and digital noise power spectrum (NPS). Accurate evaluation of MTF, incident photon fluence, and NPS is important for precise DQE determination. In this study, we focused on the accuracy of the incident photon fluence in mammography. The incident photon fluence is calculated using the squared signal-to-noise ratio (SNRin2) value as specified in the International Electrotechnical Commission (IEC) 62220-1-2 report. However, the reported SNRin2 values were determined using a computer program, and the reported values may differ from those calculated from an X-ray spectrum that is measured with actual mammography equipment. Therefore, we evaluated the error range of reported SNRin2 values in mammography to assess the accuracy of the incident photon fluence. First, X-ray spectra from various mammography systems were measured with a CdTe spectrometer. Six mammographic X-ray units were used in this study. Second, the SNRin2 values were calculated from the measured X-ray spectra. The calculated values were compared to the reported values. The results show that the percentage differences between the calculated and reported SNRin2 values were within - 4.1% of each other. The results obtained in this study indicate that the SNRin2 values provided in the IEC report are a robust and convenient tool for calculating the incident photon fluence for DQE evaluation in mammography.
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Affiliation(s)
- Tomonobu Haba
- Department of Radiology, Fujita Health University Hospital, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, Japan.
| | - Shuji Koyama
- Brain & Mind Research Center, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi, Japan
| | - Natsuki Otani
- Department of Radiological Technology, Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi, Japan
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Muñoz ID, Gamboa-deBuen I, Avila O, Brandan ME. Dosimetry in a mammography phantom using TLD-300 dosimeters. Med Phys 2018; 45:4287-4296. [PMID: 29989176 DOI: 10.1002/mp.13084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 06/25/2018] [Accepted: 06/27/2018] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The purpose of this study was to evaluate the photon field effective energy (Eeff ) distribution and percentage depth-dose (PDD) within a mammography phantom by the analysis of the CaF2 :Tm (TLD-300) thermoluminescent (TL) glow curve. The experimental procedure involves the use of TLD-300 to determine with single dosimeter exposures both the relative dose and the beam quality. METHODS TLD-300 chips were exposed to x rays from a GE Senographe 2000D mammography unit at the surface and different depths within a BR12 phantom. X-ray beams were generated with Mo/Mo, Mo/Rh, and Rh/Rh anode/filter combinations and voltages between 25 and 34 kV. Glow curves were deconvoluted into component peaks and the high- to low-temperature ratio (HLTR) was evaluated. The photon field Eeff was obtained from the HLTR values using a calibration curve determined previously. PDD was established from the peak 5 TL signal (TLSP5 ) at depths between 0.0 and 3.5 cm inside the phantom. Taking into account the differences in density and composition between CaF2 :Tm and breast tissue, an energy-dependent correction factor (β(E)) was applied to TLSP5 . Measurements were compared with radiation transport Monte Carlo (MC) simulations performed with PENELOPE-2008. RESULTS A typical 5% change in the HLTR from the phantom top surface to 3.5 cm depth was measured, which corresponds to a 2.2 keV increase in photon field Eeff . Values of the β(E) correction factor were 0.33 and 0.13 for Eeff equal to 15.1 and 22.5 keV, respectively. This strong energy dependence of β(E) is mostly due to the differences in fluence attenuation between CaF2 and breast tissue. According to PDD measurements, dose decreased to half the surface value at depths between 0.7 and 1.0 cm for Mo/Mo/25 and Rh/Rh/34 beams, respectively. Values of PDD, less than 10% at 3.5 cm depth, would have been overestimated by about 3.5% (a large relative error) if an energy-independent correction factor had been assumed. Mean differences between experiments and MC simulations were 0.8 keV and 1.2% in the determination of Eeff and PDD, respectively. CONCLUSION The TLD-300 glow curve was used to accurately measure the photon field Eeff and PDD within a mammographic phantom. This work has demonstrated that Eeff and dose can be established simultaneously by using solely TLD-300.
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Affiliation(s)
- I D Muñoz
- Instituto de Física, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - I Gamboa-deBuen
- Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - O Avila
- Instituto Nacional de Investigaciones Nucleares, 11801, Mexico City, Mexico
| | - M E Brandan
- Instituto de Física, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
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36
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Homogeneous vs. patient specific breast models for Monte Carlo evaluation of mean glandular dose in mammography. Phys Med 2018; 51:56-63. [DOI: 10.1016/j.ejmp.2018.04.392] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/05/2018] [Accepted: 04/17/2018] [Indexed: 12/15/2022] Open
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Elangovan P, Mackenzie A, Dance DR, Young KC, Wells K. Lesion detectability in 2D-mammography and digital breast tomosynthesis using different targets and observers. Phys Med Biol 2018; 63:095014. [PMID: 29637906 DOI: 10.1088/1361-6560/aabd53] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This work investigates the detection performance of specialist and non-specialist observers for different targets in 2D-mammography and digital breast tomosynthesis (DBT) using the OPTIMAM virtual clinical trials (VCT) Toolbox and a 4-alternative forced choice (4AFC) assessment paradigm. Using 2D-mammography and DBT images of virtual breast phantoms, we compare the detection limits of simple uniform spherical targets and irregular solid masses. Target diameters of 4 mm and 6 mm have been chosen to represent target sizes close to the minimum detectable size found in breast screening, across a range of controlled contrast levels. The images were viewed by a set of specialist observers (five medical physicists and six experienced clinical readers) and five non-specialists. Combined results from both observer groups indicate that DBT has a significantly lower detectable threshold contrast than 2D-mammography for small masses (4 mm: 2.1% [DBT] versus 6.9% [2D]; 6 mm: 0.7% [DBT] versus 3.9% [2D]) and spheres (4 mm: 2.9% [DBT] versus 5.3% [2D]; 6 mm: 0.3% [DBT] versus 2.2% [2D]) (p < 0.0001). Both observer groups found spheres significantly easier to detect than irregular solid masses for both sizes and modalities (p < 0.0001) (except 4 mm DBT). The detection performances of specialist and non-specialist observers were generally found to be comparable, where each group marginally outperformed the other in particular detection tasks. Within the specialist group, the clinical readers performed better than the medical physicists with irregular masses (p < 0.0001). The results indicate that using spherical targets in such studies may produce over-optimistic detection thresholds compared to more complex masses, and that the superiority of DBT for detecting masses over 2D-mammography has been quantified. The results also suggest specialist observers may be supplemented by non-specialist observers (with training) in some types of 4AFC studies.
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Affiliation(s)
- Premkumar Elangovan
- Medical Imaging Group, Centre for Vision, Speech, and Signal Processing, University of Surrey, Guildford, GU2 7XH, United Kingdom. National Co-ordinating Centre for the Physics of Mammography (NCCPM), Royal Surrey County Hospital, Guildford GU2 7XX, United Kingdom
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Suleiman ME, Brennan PC, Ekpo E, Kench P, McEntee MF. Integrating mammographic breast density in glandular dose calculation. Br J Radiol 2018; 91:20180032. [PMID: 29400552 PMCID: PMC6190790 DOI: 10.1259/bjr.20180032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE This work proposes the use of mammographic breast density (MBD) to estimate actual glandular dose (AGD), and assesses how AGD compares to mean glandular dose (MGD) estimated using Dance et al method. METHODS A retrospective sample of anonymised mammograms (52,405) was retrieved from a central database. Technical parameters and patient characteristics were exported from the Digital Imaging and Communication in Medicine (DICOM) header using third party software. LIBRA (Laboratory for Individualized Breast Radiodensity Assessment) software package (University of Pennsylvania, Philadelphia, USA) was used to estimate MBDs for each mammogram included in the data set. MGD was estimated using Dance et al method, while AGD was calculated by replacing Dance et al standard glandularities with LIBRA estimated MBDs. A linear regression analysis was used to assess the association between MGD and AGD, and a Bland-Altman analysis was performed to assess their mean difference. RESULTS The final data set included 31,097 mammograms from 7728 females. MGD, AGD, and MBD medians were 1.53 , 1.62 mGy and 8% respectively. When stratified per breast thickness ranges, median MBDs were lower than Dance's standard glandularities. There was a strong positive correlation (R2 = 0.987, p < 0.0001) between MGD and AGD although the Bland-Altman analysis revealed a small statistically significant bias of 0.087 mGy between MGD and AGD (p < 0.001). CONCLUSION AGD estimated from MBD is highly correlated to MGD from Dance method, albeit the Dance method underestimates dose at smaller CBTs. Advances in knowledge: Our work should provide a stepping-stone towards an individualised dose estimation using automated clinical measures of MBD.
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Affiliation(s)
- Moayyad E Suleiman
- Medical Radiation Sciences, The University of Sydney, Faculty of Health Sciences. Cumberland Campus, Lidcombe, NSW, Australia
| | - Patrick C Brennan
- Medical Radiation Sciences, The University of Sydney, Faculty of Health Sciences. Cumberland Campus, Lidcombe, NSW, Australia
| | - Ernest Ekpo
- Medical Radiation Sciences, The University of Sydney, Faculty of Health Sciences. Cumberland Campus, Lidcombe, NSW, Australia
| | - Peter Kench
- Medical Radiation Sciences, The University of Sydney, Faculty of Health Sciences. Cumberland Campus, Lidcombe, NSW, Australia
| | - Mark F McEntee
- Medical Radiation Sciences, The University of Sydney, Faculty of Health Sciences. Cumberland Campus, Lidcombe, NSW, Australia
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Zhou A, White GL, Davidson R. Validation of a Monte Carlo code system for grid evaluation with interference effect on Rayleigh scattering. Phys Med Biol 2018; 63:03NT02. [DOI: 10.1088/1361-6560/aaa44b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Østerås BH, Skaane P, Gullien R, Martinsen ACT. Average glandular dose in paired digital mammography and digital breast tomosynthesis acquisitions in a population based screening program: effects of measuring breast density, air kerma and beam quality. ACTA ACUST UNITED AC 2018; 63:035006. [DOI: 10.1088/1361-6560/aaa614] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Masai H, Okada G, Torimoto A, Usui T, Kawaguchi N, Yanagida T. X-ray-induced Scintillation Governed by Energy Transfer Process in Glasses. Sci Rep 2018; 8:623. [PMID: 29330411 PMCID: PMC5766489 DOI: 10.1038/s41598-017-18954-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/20/2017] [Indexed: 11/09/2022] Open
Abstract
The efficiency of X-ray-induced scintillation in glasses roughly depends on both the effective atomic number Zeff and the photoluminescence quantum efficiency Qeff of glass, which are useful tools for searching high-performance phosphors. Here, we demonstrate that the energy transfer from host to activators is also an important factor for attaining high scintillation efficiency in Ce-doped oxide glasses. The scintillation intensity of glasses with coexisting fractions of Ce3+ and Ce4+ species is found to be higher than that of a pure-Ce3+-containing glass with a lower Zeff value. Values of total attenuation of each sample indicate that there is a non-linear correlation between the scintillation intensity and the product of total attenuation and Qeff. The obtained results illustrate the difficulty in understanding the luminescence induced by ionizing radiation, including the energy absorption and subsequent energy transfer. Our findings may provide a new approach for synthesizing novel scintillators by tailoring the local structure.
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Affiliation(s)
- Hirokazu Masai
- National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka, 563-8577, Japan.
| | - Go Okada
- Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan
| | - Aya Torimoto
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Takaaki Usui
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Noriaki Kawaguchi
- Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan
| | - Takayuki Yanagida
- Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan
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Jeon H, Youn H, Kim JS, Nam J, Lee J, Lee J, Park D, Kim W, Ki Y, Kim D. Generation of polychromatic projection for dedicated breast computed tomography simulation using anthropomorphic numerical phantom. PLoS One 2017; 12:e0187242. [PMID: 29108024 PMCID: PMC5673211 DOI: 10.1371/journal.pone.0187242] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 10/17/2017] [Indexed: 11/21/2022] Open
Abstract
Numerical simulations are fundamental to the development of medical imaging systems because they can save time and effort in research and development. In this study, we developed a method of creating the virtual projection images that are necessary to study dedicated breast computed tomography (BCT) systems. Anthropomorphic software breast phantoms of the conventional compression type were synthesized and redesigned to meet the requirements of dedicated BCT systems. The internal structure of the breast was randomly constructed to develop the proposed phantom, enabling the internal structure of a naturally distributed real breast to be simulated. When using the existing monochromatic photon incidence assumption for projection-image generation, it is not possible to simulate various artifacts caused by the X-ray spectrum, such as the beam hardening effect. Consequently, the system performance could be overestimated. Therefore, we considered the polychromatic spectrum in the projection image generation process and verified the results. The proposed method is expected to be useful for the development and optimization of BCT systems.
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Affiliation(s)
- Hosang Jeon
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Hanbean Youn
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Jin Sung Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Jiho Nam
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Jayoung Lee
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Juhye Lee
- Department of Radiation Oncology and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeongsangnam-do, South Korea
| | - Dahl Park
- Department of Radiation Oncology, Pusan National University Hospital, Busan, South Korea
| | - Wontaek Kim
- Department of Radiation Oncology, Pusan National University Hospital, Busan, South Korea
| | - Yongkan Ki
- Department of Radiation Oncology, Pusan National University Hospital, Busan, South Korea
| | - Donghyun Kim
- Department of Radiation Oncology, Pusan National University Hospital, Busan, South Korea
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Rodrigues M, Di Maria S, Baptista M, Belchior A, Afonso J, Venâncio J, Vaz P. Influence of X-ray scatter radiation on image quality in Digital Breast Tomosynthesis (DBT). Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2016.12.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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van der Velden S, Bastiaannet R, Braat AJAT, Lam MGEH, Viergever MA, de Jong HWAM. Estimation of lung shunt fraction from simultaneous fluoroscopic and nuclear images. Phys Med Biol 2017; 62:8210-8225. [PMID: 28837044 DOI: 10.1088/1361-6560/aa8840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Radioembolisation with yttrium-90 (90Y) is increasingly used as a treatment of unresectable liver malignancies. For safety, a scout dose of technetium-99m macroaggregated albumin (99mTc-MAA) is used prior to the delivery of the therapeutic activity to mimic the deposition of 90Y. One-day procedures are currently limited by the lack of nuclear images in the intervention room. To cope with this limitation, an interventional simultaneous fluoroscopic and nuclear imaging device is currently being developed. The purpose of this simulation study was to evaluate the accuracy of estimating the lung shunt fraction (LSF) of the scout dose in the intervention room with this device and compare it against current clinical methods. METHODS A male and female XCAT phantom, both with two respiratory profiles, were used to simulate various LSFs resulting from a scout dose of 150 MBq 99mTc-MAA. Hybrid images were Monte Carlo simulated for breath-hold (5 s) and dynamic breathing (10 frames of 0.5 s) acquisitions. Nuclear images were corrected for attenuation with the fluoroscopic image and for organ overlap effects using a pre-treatment CT-scan. For comparison purposes, planar scintigraphy and mobile gamma camera images (both 300 s acquisition time) were simulated. Estimated LSFs were evaluated for all methods and compared to the phantom ground truth. RESULTS In the clinically relevant range of 10-20% LSF, hybrid imaging overestimated LSF with approximately 2 percentage points (pp) and 3 pp for the normal and irregular breathing phantoms, respectively. After organ overlap correction, LSF was estimated with a more constant error. Errors in planar scintigraphy and mobile gamma camera imaging were more dependent on LSF, body shape and breathing profile. CONCLUSION LSF can be estimated with a constant minor error with a hybrid imaging device. Estimated LSF is highly dependent on true LSF, body shape and breathing pattern when estimated with current clinical methods. The hybrid imaging device is capable of accurately estimating LSF within a few seconds in an interventional setting.
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Affiliation(s)
- Sandra van der Velden
- Radiology and Nuclear Medicine, UMC Utrecht, Mail E01.132, PO Box 85500, 3508 GA, Utrecht, Netherlands. Image Sciences Institute, UMC Utrecht, P.O. Box 85500, 3508 GA, Utrecht, Netherlands
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Mettivier G, Bliznakova K, Sechopoulos I, Boone JM, Di Lillo F, Sarno A, Castriconi R, Russo P. Evaluation of the BreastSimulator software platform for breast tomography. Phys Med Biol 2017; 62:6446-6466. [PMID: 28398906 DOI: 10.1088/1361-6560/aa6ca3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this work was the evaluation of the software BreastSimulator, a breast x-ray imaging simulation software, as a tool for the creation of 3D uncompressed breast digital models and for the simulation and the optimization of computed tomography (CT) scanners dedicated to the breast. Eight 3D digital breast phantoms were created with glandular fractions in the range 10%-35%. The models are characterised by different sizes and modelled realistic anatomical features. X-ray CT projections were simulated for a dedicated cone-beam CT scanner and reconstructed with the FDK algorithm. X-ray projection images were simulated for 5 mono-energetic (27, 32, 35, 43 and 51 keV) and 3 poly-energetic x-ray spectra typically employed in current CT scanners dedicated to the breast (49, 60, or 80 kVp). Clinical CT images acquired from two different clinical breast CT scanners were used for comparison purposes. The quantitative evaluation included calculation of the power-law exponent, β, from simulated and real breast tomograms, based on the power spectrum fitted with a function of the spatial frequency, f, of the form S(f) = α/f β . The breast models were validated by comparison against clinical breast CT and published data. We found that the calculated β coefficients were close to that of clinical CT data from a dedicated breast CT scanner and reported data in the literature. In evaluating the software package BreastSimulator to generate breast models suitable for use with breast CT imaging, we found that the breast phantoms produced with the software tool can reproduce the anatomical structure of real breasts, as evaluated by calculating the β exponent from the power spectral analysis of simulated images. As such, this research tool might contribute considerably to the further development, testing and optimisation of breast CT imaging techniques.
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Affiliation(s)
- G Mettivier
- Dipartimento di Fisica 'Ettore Pancini', Università di Napoli Federico II, and INFN Sezione di Napoli, I-80126 Napoli, Italy
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Scaduto DA, Tousignant O, Zhao W. Experimental characterization of a direct conversion amorphous selenium detector with thicker conversion layer for dual‐energy contrast‐enhanced breast imaging. Med Phys 2017; 44:3965-3977. [PMID: 28543761 DOI: 10.1002/mp.12358] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/29/2017] [Accepted: 05/09/2017] [Indexed: 12/17/2022] Open
Affiliation(s)
- David A. Scaduto
- Department of Radiology Stony Brook Medicine Stony Brook NY 11794‐8460 USA
| | | | - Wei Zhao
- Department of Radiology Stony Brook Medicine Stony Brook NY 11794‐8460 USA
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Mackenzie A, Eales TD, Dunn HL, Yip Braidley M, Dance DR, Young KC. Simulation of images of CDMAM phantom and the estimation of measurement uncertainties of threshold gold thickness. Phys Med 2017; 39:137-146. [PMID: 28647448 DOI: 10.1016/j.ejmp.2017.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/23/2017] [Accepted: 06/16/2017] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To demonstrate a method of simulating mammography images of the CDMAM phantom and to investigate the coefficient of variation (CoV) in the threshold gold thickness (tT) measurements associated with use of the phantom. METHODS The noise and sharpness of Hologic Dimensions and GE Essential mammography systems were characterized to provide data for the simulation. The simulation method was validated by comparing the tT results of real and simulated images of the CDMAM phantom for three different doses and the two systems. The detection matrices produced from each of 64 images using CDCOM software were randomly resampled to create 512 sets of 8, 16 and 32 images to estimate the CoV of tT. Sets of simulated images for a range of doses were used to estimate the CoVs for a range of diameters and threshold thicknesses. RESULTS No significant differences were found for tT or the CoV between real and simulated CDMAM images. It was shown that resampling from 256 images was required for estimating the CoV. The CoV was around 4% using 16 images for most of the phantom but is over double that for details near the edge of the phantom. CONCLUSIONS We have demonstrated a method to simulate images of the CDMAM phantom for different systems at a range of doses. We provide data for calculating uncertainties in tT. Any future review of the European guidelines should take into consideration the calculated uncertainties for the 0.1mm detail.
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Affiliation(s)
- Alistair Mackenzie
- National Coordinating Centre for the Physics in Mammography (NCCPM), Level B, St Luke's Wing, Royal Surrey County Hospital, Guildford GU2 7XX, UK.
| | - Timothy D Eales
- Department of Physics, University of Surrey, Guildford GU2 7XH, UK.
| | - Hannah L Dunn
- Department of Physics, University of Surrey, Guildford GU2 7XH, UK.
| | - Mary Yip Braidley
- Clinical Trials and Statistical Unit, Institute of Cancer Research, London SW7 3RP, UK.
| | - David R Dance
- National Coordinating Centre for the Physics in Mammography (NCCPM), Level B, St Luke's Wing, Royal Surrey County Hospital, Guildford GU2 7XX, UK; Department of Physics, University of Surrey, Guildford GU2 7XH, UK.
| | - Kenneth C Young
- National Coordinating Centre for the Physics in Mammography (NCCPM), Level B, St Luke's Wing, Royal Surrey County Hospital, Guildford GU2 7XX, UK; Department of Physics, University of Surrey, Guildford GU2 7XH, UK.
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Sarno A, Mettivier G, Russo P. Air kerma calculation in Monte Carlo simulations for deriving normalized glandular dose coefficients in mammography. ACTA ACUST UNITED AC 2017; 62:N337-N349. [DOI: 10.1088/1361-6560/aa7016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Antonio Sarno
- Università di Napoli Federico II, Dipartimento di Fisica 'Ettore Pancini', I-80126 Napoli, Italy. INFN Sezione di Napoli, I-80126 Napoli, Italy
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Fang Y, Ito T, Nariyuki F, Kuwabara T, Badano A, Karim KS. Technical Note: Detective quantum efficiency simulation of a-Se imaging detectors using ARTEMIS. Med Phys 2017; 44:4035-4039. [PMID: 28569992 DOI: 10.1002/mp.12389] [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: 11/12/2016] [Revised: 05/09/2017] [Accepted: 05/24/2017] [Indexed: 11/10/2022] Open
Abstract
PURPOSE This work studies the detective quantum efficiency (DQE) of a-Se-based solid state x-ray detectors for medical imaging applications using ARTEMIS, a Monte Carlo simulation tool for modeling x-ray photon, electron and charged carrier transport in semiconductors with the presence of applied electric field. METHODS ARTEMIS is used to model the signal formation process in a-Se. The simulation model includes x-ray photon and high-energy electron interactions, and detailed electron-hole pair transport with applied detector bias taking into account drift, diffusion, Coulomb interactions, recombination and trapping. For experimental validation, the DQE performance of prototype a-Se detectors is measured following IEC Testing Standard 62220-1-3. RESULTS Comparison of simulated and experimental DQE results show reasonable agreement for RQA beam qualities. Experimental validation demonstrated within 5% percentage difference between simulation and experimental DQE results for spatial frequency above 0.25 cycles/mm using uniform applied electric field for RQA beam qualities (RQA5, RQA7 and RQA9). Results include two different prototype detectors with thicknesses of 240 μm and 1 mm. CONCLUSIONS ARTEMIS can be used to model the DQE of a-Se detectors as a function of x-ray energy, detector thickness, and spatial frequency. The ARTEMIS model can be used to improve understanding of the physics of x-ray interactions in a-Se and in optimization studies for the development of novel medical imaging applications.
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Affiliation(s)
- Yuan Fang
- Division of Imaging Diagnostics and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA.,Medical Systems Research & Development Center, R&D Management Headquarters, FUJIFILM Corp, 798, Miyanodai, Kaisei-machi, Ashigarakami-gun, Kanagawa, 258-8538, Japan.,Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, N2L3G1, Canada
| | - Takaaki Ito
- Medical Systems Research & Development Center, R&D Management Headquarters, FUJIFILM Corp, 798, Miyanodai, Kaisei-machi, Ashigarakami-gun, Kanagawa, 258-8538, Japan
| | - Fumito Nariyuki
- Medical Systems Research & Development Center, R&D Management Headquarters, FUJIFILM Corp, 798, Miyanodai, Kaisei-machi, Ashigarakami-gun, Kanagawa, 258-8538, Japan
| | - Takao Kuwabara
- Medical Systems Research & Development Center, R&D Management Headquarters, FUJIFILM Corp, 798, Miyanodai, Kaisei-machi, Ashigarakami-gun, Kanagawa, 258-8538, Japan
| | - Aldo Badano
- Division of Imaging Diagnostics and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA
| | - Karim S Karim
- Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, N2L3G1, Canada
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Santos JC, Tomal A, Furquim TA, Fausto AMF, Nogueira MS, Costa PR. Direct measurement of clinical mammographic x-ray spectra using a CdTe spectrometer. Med Phys 2017; 44:3504-3511. [DOI: 10.1002/mp.12287] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 03/29/2017] [Accepted: 04/11/2017] [Indexed: 01/17/2023] Open
Affiliation(s)
- Josilene C. Santos
- Instituto de Física; Universidade de São Paulo; São Paulo SP 05508-090 Brazil
| | - Alessandra Tomal
- Instituto de Física Gleb Wataghin; Universidade Estadual de Campinas; Campinas SP 13083-859 Brazil
| | - Tânia A. Furquim
- Instituto de Física; Universidade de São Paulo; São Paulo SP 05508-090 Brazil
| | - Agnes M. F. Fausto
- Departamento de Ciências Exatas e Tecnológicas; Universidade Estadual de Santa Cruz; Ilhéus BA 45662-900 Brazil
| | - Maria S. Nogueira
- Centro de Desenvolvimento de Tecnologia Nuclear; Comissão Nacional de Energia Nuclear; Belo Horizonte MG 31270-901 Brazil
| | - Paulo R. Costa
- Instituto de Física; Universidade de São Paulo; São Paulo SP 05508-090 Brazil
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