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Matias F, Silva TF, Koval NE, Pereira JJN, Antunes PCG, Siqueira PTD, Tabacniks MH, Yoriyaz H, Shorto JMB, Grande PL. Efficient computational modeling of electronic stopping power of organic polymers for proton therapy optimization. Sci Rep 2024; 14:9868. [PMID: 38684890 PMCID: PMC11058815 DOI: 10.1038/s41598-024-60651-0] [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: 02/05/2024] [Accepted: 04/25/2024] [Indexed: 05/02/2024] Open
Abstract
This comprehensive study delves into the intricate interplay between protons and organic polymers, offering insights into proton therapy in cancer treatment. Focusing on the influence of the spatial electron density distribution on stopping power estimates, we employed real-time time-dependent density functional theory coupled with the Penn method. Surprisingly, the assumption of electron density homogeneity in polymers is fundamentally flawed, resulting in an overestimation of stopping power values at energies below 2 MeV. Moreover, the Bragg rule application in specific compounds exhibited significant deviations from experimental data around the stopping maximum, challenging established norms.
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Affiliation(s)
- F Matias
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil.
| | - T F Silva
- Instituto de Física da Universidade de São Paulo, Rua do Matão, trav. R187, São Paulo, 05508-090, Brazil
| | - N E Koval
- Centro de Física de Materiales, Paseo Manuel de Lardizabal 5, Donostia-San Sebastián, 20018, Spain
| | - J J N Pereira
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - P C G Antunes
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - P T D Siqueira
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - M H Tabacniks
- Instituto de Física da Universidade de São Paulo, Rua do Matão, trav. R187, São Paulo, 05508-090, Brazil
| | - H Yoriyaz
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - J M B Shorto
- Instituto de Pesquisas Energéticas e Nucleares, Av. Professor Lineu Prestes, São Paulo, 05508-000, Brazil
| | - P L Grande
- Instituto de Física da Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, Porto Alegre, 9500, Brazil
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Tanguay J, Basharat F. Xenon-enhanced dual-energy tomosynthesis for functional imaging of respiratory disease-Concept and phantom study. Med Phys 2023; 50:719-736. [PMID: 36419344 DOI: 10.1002/mp.16101] [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: 04/09/2022] [Revised: 10/21/2022] [Accepted: 10/23/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Xenon-enhanced dual-energy (DE) computed tomography (CT) and hyperpolarized noble-gas magnetic resonance imaging (MRI) provide maps of lung ventilation that can be used to detect chronic obstructive pulmonary disease (COPD) early in its development and predict respiratory exacerbations. However, xenon-enhanced DE-CT requires high radiation doses and hyper-polarized noble-gas MRI is expensive and only available at a handful of institutions globally. PURPOSE To present xenon-enhanced dual-energy tomosynthesis (XeDET) for low-dose, low-cost functional imaging of respiratory disease in an experimental phantom study. METHODS We propose using digital tomosynthesis to produce Xe-enhanced low-energy (LE) and high-energy (HE) coronal images. DE subtraction of the LE and HE images is used to suppress soft tissues. We used an imaging phantom to investigate image quality in terms of the area under the reciever operating characteristic curve (AUC) for the Non-PreWhitening model observer with an Eye filter and internal noise (NPWEi). The phantom simulated anatomic clutter due to lung parenchyma and attenuation due to soft tissue and lung tissue. Aluminum slats were used to simulate rib structures. A stepwedge consisting of an acrylic casing with sealed cylindrical air-filled cavities was used to simulate ventilation defects with step thicknesses of 0.5, 1, and 2 cm and cylindrical radii of 0.5, 0.75, and 1 cm. The phantom was ventilated with Xe and projection data were acquired using a flat-panel detector, a tube-voltage combination of 60/140 kV with 1.2 mm of copper filtration on the HE spectrum and an angular range of ± 15 ∘ $\pm 15^{\circ}$ in 1° increments. The AUC of a NPWEi observer that has access only to a single coronal slice was calculated from measurements of the three-dimensional noise power spectrum and signal template. The AUC was calculated as a function of ventilation defect thickness and radius for total patient entrance air kermas ranging from 1.42 to 2.84 mGy with and without rib-simulating Al slats. For the AUC analysis, the observer internal noise level was obtained from an ad hoc calibration to a high-dose data set. RESULTS XeDET was able to suppress parenchyma-simulating clutter in coronal images enabling visualization of the simulated ventilation defects, but the limited angle acquisition resulted in residual clutter due to out-of-plane bone-mimmicking structures. The signal power of the defects increased linearly with defect radius and showed a ten-fold to fifteen-fold increase in signal power when the defect thickness increased from 0.5 to 2 cm. These trends agreed with theoretical predictions. Along the depth dimension, the power of the defects decreased exponentially with distance from the center of the defects with full-width half maxima that varied from 1.85 to 2.85 cm depending on the defect thickness and radius. The AUCs of the 1-cm-radius defect that was 2 cm in thickness ranged from good (0.8-0.9) to excellent (0.9-1.0) over the range of air kermas considered. CONCLUSIONS Xenon-enhanced DE tomosynthesis has the potential to enable functional imaging of respiratory disease and should be further investigated as a low-cost alternative to MRI-based approaches and a low-dose alternative to CT-based approaches.
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Affiliation(s)
- Jesse Tanguay
- Department of Physics, Toronto Metropoliton University (formerly Ryerson University), Toronto, ON, Canada
| | - Fateen Basharat
- Department of Physics, Toronto Metropoliton University (formerly Ryerson University), Toronto, ON, Canada
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Primidis TG, Wells SG, Soloviev VY, Welsch CP. 3D chest tomosynthesis using a stationary flat panel source array and a stationary detector: a Monte Carlo proof of concept. Biomed Phys Eng Express 2021; 8. [PMID: 34757950 DOI: 10.1088/2057-1976/ac3880] [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: 08/02/2021] [Accepted: 11/10/2021] [Indexed: 11/12/2022]
Abstract
3D imaging modalities such as computed tomography and digital tomosynthesis typically scan the patient from different angles with a lengthy mechanical movement of a single x-ray tube. Therefore, millions of 3D scans per year require expensive mechanisms to support a heavy x-ray source and have to compensate for machine vibrations and patient movements. However, recent developments in cold-cathode field emission technology allow the creation of compact, stationary arrays of emitters. Adaptix Ltd has developed a novel, low-cost, square array of such emitters and demonstrated 3D digital tomosynthesis of human extremities and small animals. The use of cold-cathode field emitters also makes the system compact and lightweight. This paper presents Monte Carlo simulations of a concept upgrade of the Adaptix system from the current 60 kVp to 90 kVp and 120 kVp which are better suited for chest imaging. Between 90 kVp and 120 kVp, 3D image quality appears insensitive to voltage and at 90 kVp the photon yield is reduced by 40%-50% while effective dose declines by 14%. A square array of emitters can adequately illuminate a subject for tomosynthesis from a shorter source-to-image distance, thereby reducing the required input power, and offsetting the 28%-50% more input power that is required for operation at 90 kVp. This modelling suggests that lightweight, stationary cold-cathode x-ray source arrays could be used for chest tomosynthesis at a lower voltage, with less dose and without sacrificing image quality. This will reduce weight, size and cost, enabling 3D imaging to be brought to the bedside.
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Affiliation(s)
- Thomas G Primidis
- Department of Physics, University of Liverpool, Liverpool, United Kingdom.,The Cockcroft Institute, Sci-Tech Daresbury, Warrington, United Kingdom
| | - Stephen G Wells
- Adaptix Ltd, Oxford University Begbroke Science Park, Oxford, United Kingdom
| | - Vadim Y Soloviev
- Adaptix Ltd, Oxford University Begbroke Science Park, Oxford, United Kingdom
| | - Carsten P Welsch
- Department of Physics, University of Liverpool, Liverpool, United Kingdom.,The Cockcroft Institute, Sci-Tech Daresbury, Warrington, United Kingdom
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Rossi Norrlund R, Meltzer C, Söderman C, Johnsson ÅA, Vikgren J, Molnar D, Gilljam M, Båth M. EVALUATION OF TWO CHEST TOMOSYNTHESIS CYSTIC FIBROSIS SCORING SYSTEMS USING HIGH-RESOLUTION COMPUTED TOMOGRAPHY BRODY SCORING AS REFERENCE. RADIATION PROTECTION DOSIMETRY 2021; 195:443-453. [PMID: 33948650 DOI: 10.1093/rpd/ncab057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 03/22/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
PURPOSE To evaluate two chest tomosynthesis (CTS) scoring systems for cystic fibrosis (CF), one system developed by Vult von Steyern et al. (VvS) and one system based on the Brody scoring system for high-resolution computed tomography (HRCT) (modified Brody (mB)). Brody scoring of HRCT was used as reference. METHODS In conjunction with routine control HRCT at clinical follow-up, 10 consecutive adult CF patients underwent CTS for research purposes. Four radiologists scored the CTS examinations using the mB and VvS scoring systems. All scores were compared to the Brody HRCT scores. The agreement between the evaluated CTS scoring systems and the reference HRCT scoring system was determined using Spearman's rank correlation coefficient and the intraclass correlation coefficient (ICC). MAJOR FINDINGS Spearman's rank correlation coefficient showed strong correlations between HRCT score and both the mB and the VvS CTS total scores (median rs = 0.81 and 0.85, respectively). The ICC showed strong correlation between the CTS scoring systems and the reference: 0.88 for mB and 0.85 for VvS scoring. The median time for scoring was 20 and 10 minutes for the mB and VvS scoring systems, respectively. CONCLUSIONS Both evaluated CTS scoring systems correlate well with the reference standard Brody HRCT scoring. The VvS CTS scoring system has a shorter reading time, suggesting its advantage in clinical practice.
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Affiliation(s)
- Rauni Rossi Norrlund
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 405 30, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - Carin Meltzer
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 405 30, Sweden
- Departments of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo 0372, Norway
| | - Christina Söderman
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 405 30, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - Åse Allansdotter Johnsson
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 405 30, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - Jenny Vikgren
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 405 30, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - David Molnar
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 405 30, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
| | - Marita Gilljam
- CF-Centre, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
- Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg 413 45, Sweden
| | - Magnus Båth
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg 405 30, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden
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Meltzer C, Gilljam M, Vikgren J, Norrlund RR, Vult von Steyern K, Båth M, Johnsson ÅA. QUANTIFICATION OF PULMONARY PATHOLOGY IN CYSTIC FIBROSIS-COMPARISON BETWEEN DIGITAL CHEST TOMOSYNTHESIS AND COMPUTED TOMOGRAPHY. RADIATION PROTECTION DOSIMETRY 2021; 195:434-442. [PMID: 33683309 PMCID: PMC8507459 DOI: 10.1093/rpd/ncab017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 09/18/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
PURPOSE Digital tomosynthesis (DTS) is currently undergoing validation for potential clinical implications. The aim of this study was to investigate the potential for DTS as a low-dose alternative to computed tomography (CT) in imaging of pulmonary pathology in patients with cystic fibrosis (CF). METHODS DTS and CT were performed as part of the routine triannual follow-up in 31 CF patients. Extent of disease was quantified according to modality-specific scoring systems. Statistical analysis included Spearman's rank correlation coefficient (r) and Krippendorff's alpha (α). MAJOR FINDINGS The median effective dose was 0.14 for DTS and 2.68 for CT. Intermodality correlation was very strong for total score and the subscores regarding bronchiectasis and bronchial wall-thickening (r = 0.82-0.91, P < 0.01). Interobserver reliability was high for total score, bronchiectasis and mucus plugging (α = 0.83-0.93) in DTS. CONCLUSION Chest tomosynthesis could be a low-dose alternative to CT in quantitative estimation of structural lung disease in CF.
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Affiliation(s)
| | - M Gilljam
- Gothenburg CF-Center, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg Sweden
| | - J Vikgren
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Bruna stråket 11b V 2 SU/Sahlgrenska, 413 45 Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Bruna stråket 11b V 2 SU/Sahlgrenska, 413 45 Gothenburg, Sweden
| | - R R Norrlund
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Bruna stråket 11b V 2 SU/Sahlgrenska, 413 45 Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Bruna stråket 11b V 2 SU/Sahlgrenska, 413 45 Gothenburg, Sweden
| | - K Vult von Steyern
- Center for Medical Imaging and Physiology, Skåne University Hospital, Getingevägen 4, 22185 Lund, Sweden
| | - M Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gula stråket 2B, Plan 3, 413 45 Gothenburg, Sweden
- Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, Gula stråket 2B, Plan 3, 413 45 Gothenburg, Sweden
| | - Å A Johnsson
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Bruna stråket 11b V 2 SU/Sahlgrenska, 413 45 Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Bruna stråket 11b V 2 SU/Sahlgrenska, 413 45 Gothenburg, Sweden
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Mirzai M, Meltzer C, Vikgren J, Norrlund RR, Gottfridsson B, Johnsson Å, Båth M, Svalkvist A. The Effect of Dose Reduction on Overall Image Quality in Clinical Chest Tomosynthesis. Acad Radiol 2021; 28:e289-e296. [PMID: 32709583 DOI: 10.1016/j.acra.2020.05.041] [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: 02/03/2020] [Revised: 05/27/2020] [Accepted: 05/31/2020] [Indexed: 10/23/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate the effect of reduction in effective dose on the reproduction of anatomical structures in chest tomosynthesis (CTS). MATERIALS AND METHODS Twenty-four CTS examinations acquired at exposure settings resulting in an effective dose of 0.12 mSv for an average sized patient were included in the study. The examinations underwent simulated dose reduction to dose levels corresponding to 32%, 50%, and 70% of the original dose using a previously described and validated method. The image quality was evaluated by five thoracic radiologists who rated the fulfillment of specified image quality criteria in a visual grading study. The ratings for each image quality criterion in the dose-reduced images were compared to the corresponding ratings for the full-dose examinations using visual grading characteristics (VGC) analysis. The area under the resulting VGC curve (AUCVGC) provides a measure of the difference between the ratings, where an AUCVGC of 0.5 indicates no difference. RESULTS The dose reductions resulted in inferior reproduction of structures compared to the original dose level (AUCVGC <0.5). Structures in the central region of the lung obtained the lowest AUCVGC for each dose level whereas the reproduction of structures in the parenchyma was least affected by the dose reduction. CONCLUSION Although previous studies have shown that dose reduction in CTS is possible without affecting the performance of certain clinical tasks, the reproduction of normal anatomical structures is significantly degraded even at small reductions. It is therefore important to consider the clinical purpose of the CTS examinations before deciding on a permanent dose reduction.
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Meltzer C, Fagman E, Vikgren J, Molnar D, Borna E, Beni MM, Brandberg J, Bergman B, Båth M, Johnsson ÅA. Surveillance of small, solid pulmonary nodules at digital chest tomosynthesis: data from a cohort of the pilot Swedish CArdioPulmonary bioImage Study (SCAPIS). Acta Radiol 2021; 62:348-359. [PMID: 32438877 PMCID: PMC7930602 DOI: 10.1177/0284185120923106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background Digital tomosynthesis (DTS) might be a low-dose/low-cost alternative to computed tomography (CT). Purpose To investigate DTS relative to CT for surveillance of incidental, solid pulmonary nodules. Material and Methods Recruited from a population study, 106 participants with indeterminate solid pulmonary nodules on CT underwent surveillance with concurrently performed CT and DTS. Nodule size on DTS was assessed by manual diameter measurements and semi-automatic nodule segmentations were independently performed on CT. Measurement agreement was analyzed according to Bland–Altman with 95% limits of agreement (LoA). Detection of nodule volume change > 25% by DTS in comparison to CT was evaluated with receiver operating characteristics (ROC). Results A total of 81 nodules (76%) were assessed as measurable on DTS by two independent observers. Inter- and intra-observer LoA regarding change in average diameter were ± 2 mm. Calculation of relative volume change on DTS resulted in wide inter- and intra-observer LoA in the order of ± 100% and ± 50%. Comparing relative volume change between DTS and CT resulted in LoA of –58% to 67%. The area under the ROC curve regarding the ability of DTS to detect volumetric changes > 25% on CT was 0.58 (95% confidence interval [CI] = 0.40–0.76) and 0.50 (95% CI = 0.35–0.66) for the two observers. Conclusion The results of the present study show that measurement variability limits the agreement between DTS and CT regarding nodule size change for small solid nodules.
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Affiliation(s)
- Carin Meltzer
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Norway
| | - Erika Fagman
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Jenny Vikgren
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - David Molnar
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Eivind Borna
- Krefting Research Centre, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Maral Mirzai Beni
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - John Brandberg
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Bengt Bergman
- Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden
- Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Magnus Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Åse A Johnsson
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden
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Tongkum S, Suwanpradit P, Vidhyarkorn S, Siripongsakun S, Oonsiri S, Rakvongthai Y, Khamwan K. Determination of radiation dose and low-dose protocol for digital chest tomosynthesis using radiophotoluminescent (RPL) glass dosimeters. Phys Med 2020; 73:13-21. [PMID: 32279046 DOI: 10.1016/j.ejmp.2020.03.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/07/2020] [Accepted: 03/29/2020] [Indexed: 12/24/2022] Open
Abstract
PURPOSE This study aimed to determine a low-dose protocol for digital chest tomosynthesis (DTS). METHODS Five simulated nodules with a CT number of approximately 100 HU with size diameter of 3, 5, 8, 10, and 12 mm were inserted into an anthropomorphic chest phantom (N1 Lungman model), and then scanned by DTS system (Definium 8000) with varying tube voltage, copper filter thickness, and dose ratio. Three radiophotoluminescent (RPL) glass dosimeters, type GD-352 M with a dimension of 1.5 × 12 mm, were used to measure the entrance surface air kerma (ESAK) in each protocol. The effective dose (ED) was calculated using the recorded total dose-area-product (DAP). The signal-to-noise ratio (SNR) was determined for qualitative image quality evaluation. The image criteria and nodule detection capability were scored by two experienced radiologists. The selected low-dose protocol was further applied in a clinical study with 30 pulmonary nodule follow-up patients. RESULTS The average ESAK obtained from the standard default protocol was 1.68 ± 0.15 mGy, while an ESAK of 0.47 ± 0.02 mGy was found for a low-dose protocol. The EDs for the default and low-dose protocols were 313.98 ± 0.72 µSv and 100.55 ± 0.28 µSv, respectively. There were small non-significant differences in the image criteria and nodule detection scoring between the low-dose and default protocols interpreted by two radiologists. The effective dose of 98.87 ± 0.08 µSv was obtained in clinical study after applying the low-dose protocol. CONCLUSIONS The low-dose protocol obtained in this study can substantially reduce radiation dose while preserving an acceptable image quality compared to the standard protocol.
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Affiliation(s)
- Sarawut Tongkum
- Medical Physics Graduate Program, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; Department of Diagnostic and Interventional Radiology, Chulabhorn Hospital, Bangkok 10210, Thailand
| | - Petcharleeya Suwanpradit
- Division of Diagnostic Radiology, Department of Radiology, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok 10330, Thailand
| | - Sirachat Vidhyarkorn
- Department of Diagnostic and Interventional Radiology, Chulabhorn Hospital, Bangkok 10210, Thailand
| | - Surachate Siripongsakun
- Sonographer School, Faculty of Heath Science Technology, HRH Princess Chulabhorn College of Medical Science, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Sornjarod Oonsiri
- Division of Radiation Oncology, Department of Radiology, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok 10330, Thailand
| | - Yothin Rakvongthai
- Medical Physics Graduate Program, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; Chulalongkorn University Biomedical Imaging Group, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kitiwat Khamwan
- Medical Physics Graduate Program, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; Chulalongkorn University Biomedical Imaging Group, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
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Söderman C, Johnsson ÅA, Vikgren J, Norrlund RR, Molnar D, Mirzai M, Svalkvist A, Månsson LG, Båth M. Detection of Pulmonary Nodule Growth with Chest Tomosynthesis: A Human Observer Study Using Simulated Nodules. Acad Radiol 2019; 26:508-518. [PMID: 29903641 DOI: 10.1016/j.acra.2018.05.004] [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: 03/29/2018] [Revised: 05/08/2018] [Accepted: 05/13/2018] [Indexed: 12/20/2022]
Abstract
RATIONALE AND OBJECTIVES Chest tomosynthesis has been suggested as a suitable alternative to CT for follow-up of pulmonary nodules. The aim of the present study was to investigate the possibility of detecting pulmonary nodule growth using chest tomosynthesis. MATERIALS AND METHODS Simulated nodules with volumes of approximately 100 mm3 and 300 mm3 as well as additional versions with increasing volumes were created. The nodules were inserted into images from pairs of chest tomosynthesis examinations, simulating cases where the nodule had either remained stable in size or increased in size between the two imaging occasions. Nodule volume growths ranging from 11% to 252% were included. A simulated dose reduction was applied to a subset of the cases. Cases differing in terms of nodule size, dose level, and nodule position relative to the plane of image reconstruction were included. Observers rated their confidence that the nodules were stable in size or not. The rating data for the nodules that were stable in size was compared to the rating data for the nodules simulated to have increased in size using ROC analysis. RESULTS Area under the curve values ranging from 0.65 to 1 were found. The lowest area under the curve values were found when there was a mismatch in nodule position relative to the reconstructed image plane between the two examinations. Nodule size and dose level affected the results. CONCLUSION The study indicates that chest tomosynthesis can be used to detect pulmonary nodule growth. Nodule size, dose level, and mismatch in position relative to the image reconstruction plane in the baseline and follow-up examination may affect the precision.
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Jadidi M, Båth M, Nyrén S. Dependency of image quality on acquisition protocol and image processing in chest tomosynthesis-a visual grading study based on clinical data. Br J Radiol 2018; 91:20170683. [PMID: 29565673 DOI: 10.1259/bjr.20170683] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To compare the quality of images obtained with two different protocols with different acquisition time and the influence from image post processing in a chest digital tomosynthesis (DTS) system. METHODS 20 patients with suspected lung cancer were imaged with a chest X-ray equipment with tomosynthesis option. Two examination protocols with different acquisition times (6.3 and 12 s) were performed on each patient. Both protocols were presented with two different image post-processing (standard DTS processing and more advanced processing optimised for chest radiography). Thus, 4 series from each patient, altogether 80 series, were presented anonymously and in a random order. Five observers rated the quality of the reconstructed section images according to predefined quality criteria in three different classes. Visual grading characteristics (VGC) was used to analyse the data and the area under the VGC curve (AUCVGC) was used as figure-of-merit. The 12 s protocol and the standard DTS processing were used as references in the analyses. RESULTS The protocol with 6.3 s acquisition time had a statistically significant advantage over the vendor-recommended protocol with 12 s acquisition time for the classes of criteria, Demarcation (AUCVGC = 0.56, p = 0.009) and Disturbance (AUCVGC = 0.58, p < 0.001). A similar value of AUCVGC was found also for the class Structure (definition of bone structures in the spine) (0.56) but it could not be statistically separated from 0.5 (p = 0.21). For the image processing, the VGC analysis showed a small but statistically significant advantage for the standard DTS processing over the more advanced processing for the classes of criteria Demarcation (AUCVGC = 0.45, p = 0.017) and Disturbance (AUCVGC = 0.43, p = 0.005). A similar value of AUCVGC was found also for the class Structure (0.46), but it could not be statistically separated from 0.5 (p = 0.31). CONCLUSION The study indicates that the protocol with 6.3 s acquisition time yields slightly better image quality than the vender-recommended protocol with acquisition time 12 s for several anatomical structures. Furthermore, the standard gradation processing (the vendor-recommended post-processing for DTS), yields to some extent advantage over the gradation processing/multiobjective frequency processing/flexible noise control processing in terms of image quality for all classes of criteria. Advances in knowledge: The study proves that the image quality may be strongly affected by the selection of DTS protocol and that the vendor-recommended protocol may not always be the optimal choice.
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Affiliation(s)
- Masoud Jadidi
- 1 Departments of Clinical Science, Intervention and Technology, Karolinska Institutet , Stockholm , Sweden
| | - Magnus Båth
- 2 Department of Radiation Physics, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden.,3 Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital , Gothenburg , Sweden
| | - Sven Nyrén
- 4 Molecular medicine and surgery, Karolinska intitutet , Stockholm , Sweden.,5 Department of Thoracic radiology, Karolinska University Hospital , Stockholm , Sweden
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Meltzer C, Vikgren J, Bergman B, Molnar D, Norrlund RR, Hassoun A, Gottfridsson B, Båth M, Johnsson ÅA. Detection and Characterization of Solid Pulmonary Nodules at Digital Chest Tomosynthesis: Data from a Cohort of the Pilot Swedish Cardiopulmonary Bioimage Study. Radiology 2018; 287:1018-1027. [PMID: 29613826 DOI: 10.1148/radiol.2018171481] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Purpose To investigate the performance of digital tomosynthesis (DTS) for detection and characterization of incidental solid lung nodules. Materials and Methods This prospective study was based on a population study with 1111 randomly selected participants (age range, 50-64 years) who underwent a medical evaluation that included chest computed tomography (CT). Among these, 125 participants with incidental nodules 5 mm or larger were included in this study, which added DTS in conjunction with the follow-up CT and was performed between March 2012 and October 2014. DTS images were assessed by four thoracic radiologists blinded to the true number of nodules in two separate sessions according to the 5-mm (125 participants) and 6-mm (55 participants) cut-off for follow-up of incidental nodules. Pulmonary nodules were directly marked on the images by the readers and graded regarding confidence of presence and recommendation for follow-up. Statistical analyses included jackknife free-response receiver operating characteristic, receiver operating characteristic, and Cohen κ coefficient. Results Overall detection rate ranges of CT-proven nodules 5 mm or larger and 6 mm or larger were, respectively, 49%-58% and 48%-62%. Jackknife free-response receiver operating characteristics figure of merit for detection of CT-proven nodules 5 mm or larger and 6 mm or larger was 0.47 and 0.51, respectively, and area under the receiver operating characteristic curve regarding recommendation for follow-up was 0.62 and 0.65, respectively. Conclusion Routine use of DTS would result in lower detection rates and reduced number of small nodules recommended for follow-up. © RSNA, 2018.
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Affiliation(s)
- Carin Meltzer
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
| | - Jenny Vikgren
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
| | - Bengt Bergman
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
| | - David Molnar
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
| | - Rauni Rossi Norrlund
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
| | - Asmaa Hassoun
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
| | - Bengt Gottfridsson
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
| | - Magnus Båth
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
| | - Åse A Johnsson
- From the Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (C.M., J.V., D.M., R.R.N., Å.A.J.), Department of Radiology and Nuclear Medicine at Oslo University Hospital, Ullevål, Norway (C.M.), Department of Radiology, Sahlgrenska University Hospital, Sweden (J.V., D.M., R.R.N., A.H., B.G., Å.A.J.), Department of Respiratory Medicine, Sahlgrenska University Hospital, Sweden (B.B.), Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden (B.B.), Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden (M.B.), Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden (M.B.)
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12
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Tao X, Zhang H, Qin G, Ma J, Feng Q, Chen W. Sin-quadratic model for chest tomosynthesis respiratory signal analysis and its application in four dimensional chest tomosynthesis reconstruction. Med Eng Phys 2018; 52:59-68. [PMID: 29336877 DOI: 10.1016/j.medengphy.2017.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 11/23/2017] [Accepted: 12/22/2017] [Indexed: 11/19/2022]
Abstract
Chest tomosynthesis (CTS) is a newly developed imaging technique which provides pseudo-3D volume anatomical information of thorax from limited-angle projections and contains much less of superimposed anatomy than the chest X-ray radiography. One of the relatively common problems in CTS is the patient respiratory motion during image acquisition, which negatively impacts the detectability. In this work, we propose a sin-quadratic model to analyze the respiratory motion during CTS scan, which is a real time method where the respiratory signal is generated by extracting the motion of diaphragm from projection radiographs. According to the estimated respiratory signal, the CTS projections were then amplitude-based sorted into four to eight phases, and an iterative reconstruction strategy with total variation regularization was adopted to reconstruct the CTS images at each phase. Simulated digital XCAT phantom data and three sets of patient data were adopted for the experiments to validate the performance of the sin-quadratic model and its application in four dimensional (4D) CTS reconstruction. Results of the XCAT phantom simulation study show that the correlation coefficient between the extracted respiratory signal and the originally designed respiratory signal is 0.9964, which suggests that the proposed model could exactly extract the respiratory signal from CTS projections. The 4D CTS reconstructions of both the phantom data and the patient data show clear reduction of motion-induced blur.
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Affiliation(s)
- Xi Tao
- School of Biomedical Engineering, and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou 510515, China
| | - Hua Zhang
- School of Biomedical Engineering, and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou 510515, China.
| | - Genggeng Qin
- Department of Radiology, Nanfang Hospital, Southern Medical University Guangzhou, 510515, China
| | - Jianhua Ma
- School of Biomedical Engineering, and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou 510515, China
| | - Qianjin Feng
- School of Biomedical Engineering, and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou 510515, China
| | - Wufan Chen
- School of Biomedical Engineering, and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou 510515, China
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13
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Cant J, Snoeckx A, Behiels G, Parizel PM, Sijbers J. Can portable tomosynthesis improve the diagnostic value of bedside chest X-ray in the intensive care unit? A proof of concept study. Eur Radiol Exp 2017; 1:20. [PMID: 29708195 PMCID: PMC5909351 DOI: 10.1186/s41747-017-0021-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 08/21/2017] [Indexed: 12/18/2022] Open
Abstract
Portable bedside chest X-ray (CXR) is an important and frequently used tool in the intensive care unit (ICU). Unfortunately, the diagnostic value of portable CXR is often low due to technical limitations and suboptimal patient positioning. Additionally, abnormalities in the chest may be hidden on the projection image by overlapping anatomy and devices such as endotracheal tubes, lines and catheters. Digital tomosynthesis (DTS) can solve the problem of anatomical overlap. In DTS, several low-dose X-ray images from different angles are acquired and subsequently used by a reconstruction algorithm to compute section images along planes parallel to the detector. However, a portable device to be used for portable bedside chest DTS is not on the market yet. In this work, we discuss modifications to a portable X-ray device to enable portable DTS and illustrate the potential of portable DTS to improve the diagnostic value of bedside CXR in the ICU. A simulation, based on computed tomography scans, is presented. Our experiments comparing portable DTS with conventional bedside CXR showed a substantially improved detection of pneumothorax and other abnormalities.
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14
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Söderman C, Johnsson ÅA, Vikgren J, Norrlund RR, Molnar D, Svalkvist A, Månsson LG, Båth M. EFFECT OF RADIATION DOSE LEVEL ON ACCURACY AND PRECISION OF MANUAL SIZE MEASUREMENTS IN CHEST TOMOSYNTHESIS EVALUATED USING SIMULATED PULMONARY NODULES. RADIATION PROTECTION DOSIMETRY 2016; 169:188-198. [PMID: 26994093 PMCID: PMC4911967 DOI: 10.1093/rpd/ncw041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The aim of the present study was to investigate the dependency of the accuracy and precision of nodule diameter measurements on the radiation dose level in chest tomosynthesis. Artificial ellipsoid-shaped nodules with known dimensions were inserted in clinical chest tomosynthesis images. Noise was added to the images in order to simulate radiation dose levels corresponding to effective doses for a standard-sized patient of 0.06 and 0.04 mSv. These levels were compared with the original dose level, corresponding to an effective dose of 0.12 mSv for a standard-sized patient. Four thoracic radiologists measured the longest diameter of the nodules. The study was restricted to nodules located in high-dose areas of the tomosynthesis projection radiographs. A significant decrease of the measurement accuracy and intraobserver variability was seen for the lowest dose level for a subset of the observers. No significant effect of dose level on the interobserver variability was found. The number of non-measurable small nodules (≤5 mm) was higher for the two lowest dose levels compared with the original dose level. In conclusion, for pulmonary nodules at positions in the lung corresponding to locations in high-dose areas of the projection radiographs, using a radiation dose level resulting in an effective dose of 0.06 mSv to a standard-sized patient may be possible in chest tomosynthesis without affecting the accuracy and precision of nodule diameter measurements to any large extent. However, an increasing number of non-measurable small nodules (≤5 mm) with decreasing radiation dose may raise some concerns regarding an applied general dose reduction for chest tomosynthesis examinations in the clinical praxis.
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Affiliation(s)
- Christina Söderman
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Åse Allansdotter Johnsson
- Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Jenny Vikgren
- Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Rauni Rossi Norrlund
- Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - David Molnar
- Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Angelica Svalkvist
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Lars Gunnar Månsson
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Magnus Båth
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
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Båth M, Hansson J. VGC ANALYZER: A SOFTWARE FOR STATISTICAL ANALYSIS OF FULLY CROSSED MULTIPLE-READER MULTIPLE-CASE VISUAL GRADING CHARACTERISTICS STUDIES. RADIATION PROTECTION DOSIMETRY 2016; 169:46-53. [PMID: 26769908 DOI: 10.1093/rpd/ncv542] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Visual grading characteristics (VGC) analysis is a non-parametric rank-invariant method for analysis of visual grading data. In VGC analysis, image quality ratings for two different conditions are compared by producing a VGC curve, similar to how the ratings for normal and abnormal cases in receiver operating characteristic (ROC) analysis are used to create an ROC curve. The use of established ROC software for the analysis of VGC data has therefore previously been proposed. However, the ROC analysis is based on the assumption of independence between normal and abnormal cases. In VGC analysis, this independence cannot always be assumed, e.g. if the ratings are based on the same patients imaged under both conditions. A dedicated software intended for analysis of VGC studies, which takes possible dependencies between ratings into account in the statistical analysis of a VGC study, has therefore been developed. The software-VGC Analyzer-determines the area under the VGC curve and its uncertainty using non-parametric resampling techniques. This article gives an introduction to VGC Analyzer, describes the types of analyses that can be performed and instructs the user about the input and output data.
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Affiliation(s)
- Magnus Båth
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Jonny Hansson
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
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16
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Svalkvist A, Svensson S, Håkansson M, Båth M, Månsson LG. VIEWDEX: A STATUS REPORT. RADIATION PROTECTION DOSIMETRY 2016; 169:38-45. [PMID: 26822421 DOI: 10.1093/rpd/ncv543] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
ViewDEX (Viewer for Digital Evaluation of X-ray images) is an image viewer and task manager suitable for research and optimisation tasks in medical imaging. The software has undergone continuous development during more than a decade and has during this time period been used in numerous studies. ViewDEX is DICOM compatible, and the features of the interface (tasks, image handling and functionality) are general and flexible. The set-up of a study is determined by altering properties in a text-editable file, enabling easy and flexible configuration. ViewDEX is developed in Java and can run from any disc area connected to a computer. It is free to use for non-commercial purposes and can be downloaded from http://www.vgregion.se/sas/viewdex The purposes of the present article are to give a short overview of the development of ViewDEX and to describe recent updates of the software. In addition, a description on how to configure a viewing session in ViewDEX is provided.
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Affiliation(s)
- Angelica Svalkvist
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Sune Svensson
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Markus Håkansson
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Diagnostic Radiology, Södra Älvsborgs sjukhus, SE-501 82 Borås, Sweden
| | - Magnus Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Lars Gunnar Månsson
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
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Söderman C, Johnsson ÅA, Vikgren J, Norrlund RR, Molnar D, Svalkvist A, Månsson LG, Båth M. INFLUENCE OF THE IN-PLANE ARTEFACT IN CHEST TOMOSYNTHESIS ON PULMONARY NODULE SIZE MEASUREMENTS. RADIATION PROTECTION DOSIMETRY 2016; 169:199-203. [PMID: 26769904 DOI: 10.1093/rpd/ncv536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The aim of the present study was to investigate how the in-plane artefact present in the scan direction around structures in tomosynthesis images should be managed when measuring the size of nodules in chest tomosynthesis images in order to achieve acceptable measurement accuracy. Data from measurements, performed by radiologists, of the longest diameter of artificial nodules inserted in chest tomosynthesis images were used. The association between the measurement error and the direction of the longest nodule diameter, relative to the scan direction, was evaluated using the Kendall rank correlation coefficient. All of the radiologists had chosen to not include the artefact in the measurements. Significant association between measurement error and the direction of the longest diameter was found for nodules larger than 12 mm, which indicates that, for these nodules, there is a risk of underestimating the nodule size if the in-plane artefact is omitted from manual diameter measurements.
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Affiliation(s)
- Christina Söderman
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Åse Allansdotter Johnsson
- Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Jenny Vikgren
- Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Rauni Rossi Norrlund
- Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - David Molnar
- Department of Radiology, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Angelica Svalkvist
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Lars Gunnar Månsson
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Magnus Båth
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
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18
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Meltzer C, Båth M, Kheddache S, Ásgeirsdóttir H, Gilljam M, Johnsson ÅA. VISIBILITY OF STRUCTURES OF RELEVANCE FOR PATIENTS WITH CYSTIC FIBROSIS IN CHEST TOMOSYNTHESIS: INFLUENCE OF ANATOMICAL LOCATION AND OBSERVER EXPERIENCE. RADIATION PROTECTION DOSIMETRY 2016; 169:177-87. [PMID: 26842827 PMCID: PMC4911964 DOI: 10.1093/rpd/ncv556] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The aims of this study were to assess the visibility of pulmonary structures in patients with cystic fibrosis (CF) in digital tomosynthesis (DTS) using computed tomography (CT) as reference and to investigate the dependency on anatomical location and observer experience. Anatomical structures in predefined regions of CT images from 21 patients were identified. Three observers with different levels of experience rated the visibility of the structures in DTS by performing a head-to-head comparison with visibility in CT. Visibility of the structures in DTS was reported as equal to CT in 34 %, inferior in 52 % and superior in 14 % of the ratings. Central and peripheral lateral structures received higher visibility ratings compared with peripheral structures anteriorly, posteriorly and surrounding the diaphragm (p ≤ 0.001). Reported visibility was significantly higher for the most experienced observer (p ≤ 0.01). The results indicate that minor pathology can be difficult to visualise with DTS depending on location and observer experience. Central and peripheral lateral structures are generally well depicted.
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Affiliation(s)
- Carin Meltzer
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Magnus Båth
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Susanne Kheddache
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Helga Ásgeirsdóttir
- Gothenburg CF-Center, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Marita Gilljam
- Gothenburg CF-Center, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Respiratory Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Åse Allansdotter Johnsson
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
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Arvidsson J, Söderman C, Allansdotter Johnsson Å, Bernhardt P, Starck G, Kahl F, Båth M. IMAGE FUSION OF RECONSTRUCTED DIGITAL TOMOSYNTHESIS VOLUMES FROM A FRONTAL AND A LATERAL ACQUISITION. RADIATION PROTECTION DOSIMETRY 2016; 169:410-415. [PMID: 26683464 DOI: 10.1093/rpd/ncv507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Digital tomosynthesis (DTS) has been used in chest imaging as a low radiation dose alternative to computed tomography (CT). Traditional DTS shows limitations in the spatial resolution in the out-of-plane dimension. As a first indication of whether a dual-plane dual-view (DPDV) DTS data acquisition can yield a fair resolution in all three spatial dimensions, a manual registration between a frontal and a lateral image volume was performed. An anthropomorphic chest phantom was scanned frontally and laterally using a linear DTS acquisition, at 120 kVp. The reconstructed image volumes were resampled and manually co-registered. Expert radiologist delineations of the mediastinal soft tissues enabled calculation of similarity metrics in regard to delineations in a reference CT volume. The fused volume produced the highest total overlap, implying that the fused volume was a more isotropic 3D representation of the examined object than the traditional chest DTS volumes.
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Affiliation(s)
- Jonathan Arvidsson
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Christina Söderman
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Åse Allansdotter Johnsson
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Peter Bernhardt
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Göran Starck
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Fredrik Kahl
- Department of Signals and Systems, Digital Image Systems and Image Analysis, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Magnus Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
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Jadidi M, Sundin A, Aspelin P, Båth M, Nyrén S. Evaluation of a new system for chest tomosynthesis: aspects of image quality of different protocols determined using an anthropomorphic phantom. Br J Radiol 2015; 88:20150057. [PMID: 26118300 DOI: 10.1259/bjr.20150057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To compare the image quality obtained with the different protocols in a new chest digital tomosynthesis (DTS) system. METHODS A chest phantom was imaged with chest X-ray equipment with DTS. 10 protocols were used, and for each protocol, nine acquisitions were performed. Four observers visually rated the quality of the reconstructed section images according to pre-defined quality criteria in four different classes. The data were analysed with visual grading characteristics (VGC) analysis, using the vendor-recommended protocol [12-s acquisition time, source-to-image distance (SID) 180 cm] as reference, and the area under the VGC curve (AUCVGC) was determined for each protocol and class of criteria. RESULTS Protocols with a smaller swing angle resulted in a lower image quality for the classes of criteria "disturbance" and "homogeneity in nodule" but a higher image quality for the class "structure". The class "demarcation" showed little dependency on the swing angle. All protocols but one (6.3 s, SID 130 cm) obtained an AUCVGC significantly <0.5 (indicating lower quality than reference) for at least one class of criteria. CONCLUSION The study indicates that the DTS protocol with 6.3 s yields image quality similar to that obtained with the vendor-recommended protocol (12 s) but with the clinically important advantage for patients with respiratory impairment of a shorter acquisition time. ADVANCES IN KNOWLEDGE The study demonstrates that the image quality may be strongly affected by the choice of protocol and that the vendor-recommended protocol may not be optimal.
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Affiliation(s)
- M Jadidi
- 1 Departments of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - A Sundin
- 2 Radiology Department, Uppsala University Hospital, Uppsala, Sweden.,3 Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden
| | - P Aspelin
- 4 Departments of Clinical Science, Intervention and Technology, Karolinska University Hospital, Stockholm, Sweden.,5 Radiology Department, Karolinska University Hospital, Stockholm, Sweden
| | - M Båth
- 6 Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,7 Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - S Nyrén
- 8 Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,9 Radiology Department, Karolinska Institute, Stockholm, Sweden
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