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Friedlander Y, Munidasa S, Thakar A, Ragunayakam N, Venegas C, Kjarsgaard M, Zanette B, Capaldi DPI, Santyr G, Nair P, Svenningsen S. Phase-Resolved Functional Lung (PREFUL) MRI to Quantify Ventilation: Feasibility and Physiological Relevance in Severe Asthma. Acad Radiol 2024; 31:3416-3426. [PMID: 38378325 DOI: 10.1016/j.acra.2024.01.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/28/2024] [Accepted: 01/28/2024] [Indexed: 02/22/2024]
Abstract
RATIONALE AND OBJECTIVES Emergent evidence in several respiratory diseases supports translational potential for Phase-Resolved Functional Lung (PREFUL) MRI to spatially quantify ventilation but its feasibility and physiological relevance have not been demonstrated in patients with asthma. This study compares PREFUL-derived ventilation defect percent (VDP) in severe asthma patients to healthy controls and measures its responsiveness to bronchodilator therapy and relation to established measures of airways disease. MATERIALS AND METHODS Forty-one adults with severe asthma and seven healthy controls performed same-day free-breathing 1H MRI, 129Xe MRI, spirometry, and oscillometry. A subset of participants (n = 23) performed chest CT and another subset of participants with asthma (n = 19) repeated 1H MRI following the administration of a bronchodilator. VDP was calculated for both PREFUL and 129Xe MRI. Additionally, the percent of functional small airways disease was determined from CT parametric response maps (PRMfSAD). RESULTS PREFUL VDP measured pre-bronchodilator (19.1% [7.4-43.3], p = 0.0002) and post-bronchodilator (16.9% [6.1-38.4], p = 0.0007) were significantly greater than that of healthy controls (7.5% [3.7-15.5]) and was significantly decreased post-bronchodilator (from 21.9% [10.1-36.9] to 16.9% [6.1-38.4], p = 0.0053). PREFUL VDP was correlated with spirometry (FEV1%pred: r = -0.46, p = 0.0023; FVC%pred: r = -0.35, p = 0.024, FEV1/FVC: r = -0.46, p = 0.0028), 129Xe MRI VDP (r = 0.39, p = 0.013), and metrics of small airway disease (CT PRMfSAD: r = 0.55, p = 0.021; Xrs5 Hz: r = -0.44, p = 0.0046, and AX: r = 0.32, p = 0.044). CONCLUSION PREFUL-derived VDP is responsive to bronchodilator therapy in asthma and is associated with measures of airflow obstruction and small airway dysfunction. These findings validate PREFUL VDP as a physiologically relevant and accessible ventilation imaging outcome measure in asthma.
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Affiliation(s)
- Yonni Friedlander
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare Hamilton, Hamilton, Canada
| | - Samal Munidasa
- Translational Medicine Program, The Hospital for Sick Children, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Ashutosh Thakar
- Department of Medicine, McMaster University, Hamilton, Canada
| | | | - Carmen Venegas
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare Hamilton, Hamilton, Canada; Department of Medicine, McMaster University, Hamilton, Canada
| | - Melanie Kjarsgaard
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare Hamilton, Hamilton, Canada; Department of Medicine, McMaster University, Hamilton, Canada
| | - Brandon Zanette
- Translational Medicine Program, The Hospital for Sick Children, Toronto, Canada
| | - Dante P I Capaldi
- Department of Radiation Oncology, Division of Physics, University of California, San Francisco, CA
| | - Giles Santyr
- Translational Medicine Program, The Hospital for Sick Children, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Parameswaran Nair
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare Hamilton, Hamilton, Canada; Department of Medicine, McMaster University, Hamilton, Canada
| | - Sarah Svenningsen
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare Hamilton, Hamilton, Canada; Department of Medicine, McMaster University, Hamilton, Canada.
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Hofmann JJ, Poulos VC, Zhou J, Sharma M, Parraga G, McIntosh MJ. Review of quantitative and functional lung imaging evidence of vaping-related lung injury. Front Med (Lausanne) 2024; 11:1285361. [PMID: 38327710 PMCID: PMC10847544 DOI: 10.3389/fmed.2024.1285361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 01/08/2024] [Indexed: 02/09/2024] Open
Abstract
Introduction The pulmonary effects of e-cigarette use (or vaping) became a healthcare concern in 2019, following the rapid increase of e-cigarette-related or vaping-associated lung injury (EVALI) in young people, which resulted in the critical care admission of thousands of teenagers and young adults. Pulmonary functional imaging is well-positioned to provide information about the acute and chronic effects of vaping. We generated a systematic review to retrieve relevant imaging studies that describe the acute and chronic imaging findings that underly vaping-related lung structure-function abnormalities. Methods A systematic review was undertaken on June 13th, 2023 using PubMed to search for published manuscripts using the following criteria: [("Vaping" OR "e-cigarette" OR "EVALI") AND ("MRI" OR "CT" OR "Imaging")]. We included only studies involving human participants, vaping/e-cigarette use, and MRI, CT and/or PET. Results The search identified 445 manuscripts, of which 110 (668 unique participants) specifically mentioned MRI, PET or CT imaging in cases or retrospective case series of patients who vaped. This included 105 manuscripts specific to CT (626 participants), three manuscripts which mainly used MRI (23 participants), and two manuscripts which described PET findings (20 participants). Most studies were conducted in North America (n = 90), with the remaining studies conducted in Europe (n = 15), Asia (n = 4) and South America (n = 1). The vast majority of publications described case studies (n = 93) and a few described larger retrospective or prospective studies (n = 17). In e-cigarette users and patients with EVALI, key CT findings included ground-glass opacities, consolidations and subpleural sparing, MRI revealed abnormal ventilation, perfusion and ventilation/perfusion matching, while PET showed evidence of pulmonary inflammation. Discussion and conclusion Pulmonary structural and functional imaging abnormalities were common in patients with EVALI and in e-cigarette users with or without respiratory symptoms, which suggests that functional MRI may be helpful in the investigation of the pulmonary health effects associated with e-cigarette use.
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Affiliation(s)
| | | | - Jiahai Zhou
- Robarts Research Institute, London, ON, Canada
| | - Maksym Sharma
- Robarts Research Institute, London, ON, Canada
- Department of Medical Biophysics, London, ON, Canada
| | - Grace Parraga
- Robarts Research Institute, London, ON, Canada
- Department of Medical Biophysics, London, ON, Canada
- Department of Medical Imaging, Western University, London, ON, Canada
| | - Marrissa J. McIntosh
- Robarts Research Institute, London, ON, Canada
- Department of Medical Biophysics, London, ON, Canada
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Xu P, Meersmann T, Wang J, Wang C. Review of oxygen-enhanced lung mri: Pulse sequences for image acquisition and T 1 measurement. Med Phys 2023; 50:5987-6007. [PMID: 37345214 DOI: 10.1002/mp.16553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 03/23/2023] [Accepted: 05/16/2023] [Indexed: 06/23/2023] Open
Abstract
Oxygen-enhanced MR imaging (OE-MRI) is a special proton imaging technique that can be performed without modifying the scanner hardware. Many fundamental studies have been conducted following the initial reporting of this technique in 1996, illustrating the high potential for its clinical application. This review aims to summarise and analyse current pulse sequences and T1 measurement methods for OE-MRI, including fundamental theories, existing pulse sequences applied to OE-MRI acquisition and T1 mapping. Wash-in and wash-out time identify lung function and are sensitive to ventilation; thus, dynamic OE-MRI is also discussed in this review. We compare OE-MRI with the primary competitive technique, hyperpolarised gas MRI. Finally, an overview of lower-field applications of OE-MRI is highlighted, as relatively recent publications demonstrated positive results. Lower-field OE-MRI, which is lower than 1.5 T, could be an alternative modality for detecting lung diseases. This educational review is aimed at researchers who want a quick summary of the steps needed to perform pulmonary OE-MRI with a particular focus on sequence design, settings, and quantification methods.
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Affiliation(s)
- Pengfei Xu
- Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, University of Nottingham Ningbo China, Ningbo, China
| | - Thomas Meersmann
- Sir Peter Mansfield Magnetic Imaging Centre, University of Nottingham, Nottingham, UK
- Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute, Ningbo, China
| | - Jing Wang
- Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, University of Nottingham Ningbo China, Ningbo, China
- Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute, Ningbo, China
| | - Chengbo Wang
- Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, University of Nottingham Ningbo China, Ningbo, China
- Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute, Ningbo, China
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Zanette B, Greer MLC, Moraes TJ, Ratjen F, Santyr G. The argument for utilising magnetic resonance imaging as a tool for monitoring lung structure and function in pediatric patients. Expert Rev Respir Med 2023; 17:527-538. [PMID: 37491192 DOI: 10.1080/17476348.2023.2241355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 07/06/2023] [Accepted: 07/24/2023] [Indexed: 07/27/2023]
Abstract
INTRODUCTION Although historically challenging to perform in the lung, technological advancements have made Magnetic Resonance Imaging (MRI) increasingly applicable for pediatric pulmonary imaging. Furthermore, a wide array of functional imaging techniques has become available that may be leveraged alongside structural imaging for increasingly sensitive biomarkers, or as outcome measures in the evaluation of novel therapies. AREAS COVERED In this review, recent technical advancements and modern methodologies for structural and functional lung MRI are described. These include ultrashort echo time (UTE) MRI, free-breathing contrast agent-free, functional lung MRI, and hyperpolarized gas MRI, amongst other techniques. Specific examples of the application of these methods in children are provided, principally drawn from recent research in asthma, bronchopulmonary dysplasia, and cystic fibrosis. EXPERT OPINION Pediatric lung MRI is rapidly growing, and is well poised for clinical utilization, as well as continued research into early disease detection, disease processes, and novel treatments. Structure/function complementarity makes MRI especially attractive as a tool for increased adoption in the evaluation of pediatric lung disease. Looking toward the future, novel technologies, such as low-field MRI and artificial intelligence, mitigate some of the traditional drawbacks of lung MRI and will aid in improving access to MRI in general, potentially spurring increased adoption and demand for pulmonary MRI in children.
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Affiliation(s)
- Brandon Zanette
- Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Mary-Louise C Greer
- Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
| | - Theo J Moraes
- Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Pediatrics, Hospital for Sick Children, Toronto, ON, Canada
| | - Felix Ratjen
- Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Division of Respiratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Giles Santyr
- Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
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Foo CT, Langton D, Thompson BR, Thien F. Functional lung imaging using novel and emerging MRI techniques. Front Med (Lausanne) 2023; 10:1060940. [PMID: 37181360 PMCID: PMC10166823 DOI: 10.3389/fmed.2023.1060940] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 04/03/2023] [Indexed: 05/16/2023] Open
Abstract
Respiratory diseases are leading causes of death and disability in the world. While early diagnosis is key, this has proven difficult due to the lack of sensitive and non-invasive tools. Computed tomography is regarded as the gold standard for structural lung imaging but lacks functional information and involves significant radiation exposure. Lung magnetic resonance imaging (MRI) has historically been challenging due to its short T2 and low proton density. Hyperpolarised gas MRI is an emerging technique that is able to overcome these difficulties, permitting the functional and microstructural evaluation of the lung. Other novel imaging techniques such as fluorinated gas MRI, oxygen-enhanced MRI, Fourier decomposition MRI and phase-resolved functional lung imaging can also be used to interrogate lung function though they are currently at varying stages of development. This article provides a clinically focused review of these contrast and non-contrast MR imaging techniques and their current applications in lung disease.
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Affiliation(s)
- Chuan T. Foo
- Department of Respiratory Medicine, Eastern Health, Melbourne, VIC, Australia
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
| | - David Langton
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
- Department of Thoracic Medicine, Peninsula Health, Frankston, VIC, Australia
| | - Bruce R. Thompson
- Melbourne School of Health Science, Melbourne University, Melbourne, VIC, Australia
| | - Francis Thien
- Department of Respiratory Medicine, Eastern Health, Melbourne, VIC, Australia
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
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Tibiletti M, Eaden JA, Naish JH, Hughes PJC, Waterton JC, Heaton MJ, Chaudhuri N, Skeoch S, Bruce IN, Bianchi S, Wild JM, Parker GJM. Imaging biomarkers of lung ventilation in interstitial lung disease from 129Xe and oxygen enhanced 1H MRI. Magn Reson Imaging 2023; 95:39-49. [PMID: 36252693 DOI: 10.1016/j.mri.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 11/19/2022]
Abstract
PURPOSE To compare imaging biomarkers from hyperpolarised 129Xe ventilation MRI and dynamic oxygen-enhanced MRI (OE-MRI) with standard pulmonary function tests (PFT) in interstitial lung disease (ILD) patients. To evaluate if biomarkers can separate ILD subtypes and detect early signs of disease resolution or progression. STUDY TYPE Prospective longitudinal. POPULATION Forty-one ILD (fourteen idiopathic pulmonary fibrosis (IPF), eleven hypersensitivity pneumonitis (HP), eleven drug-induced ILD (DI-ILD), five connective tissue disease related-ILD (CTD-ILD)) patients and ten healthy volunteers imaged at visit 1. Thirty-four ILD patients completed visit 2 (eleven IPF, eight HP, ten DIILD, five CTD-ILD) after 6 or 26 weeks. FIELD STRENGTH/SEQUENCE MRI was performed at 1.5 T, including inversion recovery T1 mapping, dynamic MRI acquisition with varying oxygen levels, and hyperpolarised 129Xe ventilation MRI. Subjects underwent standard spirometry and gas transfer testing. ASSESSMENT Five 1H MRI and two 129Xe MRI ventilation metrics were compared with spirometry and gas transfer measurements. STATISTICAL TEST To evaluate differences at visit 1 among subgroups: ANOVA or Kruskal-Wallis rank tests with correction for multiple comparisons. To assess the relationships between imaging biomarkers, PFT, age and gender, at visit 1 and for the change between visit 1 and 2: Pearson correlations and multilinear regression models. RESULTS The global PFT tests could not distinguish ILD subtypes. Percentage ventilated volumes were lower in ILD patients than in HVs when measured with 129Xe MRI (HV 97.4 ± 2.6, CTD-ILD: 91.0 ± 4.8 p = 0.017, DI-ILD 90.1 ± 7.4 p = 0.003, HP 92.6 ± 4.0 p = 0.013, IPF 88.1 ± 6.5 p < 0.001), but not with OE-MRI. 129Xe reported more heterogeneous ventilation in DI-ILD and IPF than in HV, and OE-MRI reported more heterogeneous ventilation in DI-ILD and IPF than in HP or CTD-ILD. The longitudinal changes reported by the imaging biomarkers did not correlate with the PFT changes between visits. DATA CONCLUSION Neither 129Xe ventilation nor OE-MRI biomarkers investigated in this study were able to differentiate between ILD subtypes, suggesting that ventilation-only biomarkers are not indicated for this task. Limited but progressive loss of ventilated volume as measured by 129Xe-MRI may be present as the biomarker of focal disease progresses. OE-MRI biomarkers are feasible in ILD patients and do not correlate strongly with PFT. Both OE-MRI and 129Xe MRI revealed more spatially heterogeneous ventilation in DI-ILD and IPF.
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Affiliation(s)
- Marta Tibiletti
- Bioxydyn Limited, Rutherford House, Manchester Science Park, Manchester M15 6SZ, United Kingdom
| | - James A Eaden
- POLARIS, University of Sheffield MRI Unit, Department of Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Josephine H Naish
- Bioxydyn Limited, Rutherford House, Manchester Science Park, Manchester M15 6SZ, United Kingdom; MCMR, Manchester University NHS Foundation Trust, Wythenshawe, Manchester, UK
| | - Paul J C Hughes
- POLARIS, University of Sheffield MRI Unit, Department of Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - John C Waterton
- Bioxydyn Limited, Rutherford House, Manchester Science Park, Manchester M15 6SZ, United Kingdom; Centre for Imaging Sciences, University of Manchester, Manchester, UK
| | - Matthew J Heaton
- Bioxydyn Limited, Rutherford House, Manchester Science Park, Manchester M15 6SZ, United Kingdom
| | - Nazia Chaudhuri
- North West Lung Centre, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Sarah Skeoch
- Royal National Hospital for Rheumatic Diseases, Royal United Hospitals Bath NHS Foundation Trust, Bath, UK
| | - Ian N Bruce
- NIHR Manchester Biomedical Research Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, UK; Centre for Musculoskeletal Research, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Stephen Bianchi
- Academic Directorate of Respiratory Medicine, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Jim M Wild
- POLARIS, University of Sheffield MRI Unit, Department of Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK; Insigneo Insititute for in silico medicine, Sheffield, UK
| | - Geoff J M Parker
- Bioxydyn Limited, Rutherford House, Manchester Science Park, Manchester M15 6SZ, United Kingdom; Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
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Bluemke E, Bertrand A, Chu KY, Syed N, Murchison AG, Cooke R, Greenhalgh T, Burns B, Craig M, Taylor N, Shah K, Gleeson F, Bulte D. Oxygen-enhanced MRI and radiotherapy in patients with oropharyngeal squamous cell carcinoma. Clin Transl Radiat Oncol 2022; 39:100563. [PMID: 36655119 PMCID: PMC9841018 DOI: 10.1016/j.ctro.2022.100563] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 12/08/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Background and purpose This study aimed to assess the role of T1 mapping and oxygen-enhanced MRI in patients undergoing radical dose radiotherapy for HPV positive oropharyngeal cancer, which has not yet been examined in an OE-MRI study. Materials and methods Variable Flip Angle T1 maps were acquired on a 3T MRI scanner while patients (n = 12) breathed air and/or 100 % oxygen, before and after fraction 10 of the planned 30 fractions of chemoradiotherapy ('visit 1' and 'visit 2', respectively). The analysis aimed to assess to what extent (1) native R1 relates to patient outcome; (2) OE-MRI response relates to patient outcome; (3) changes in mean R1 before and after radiotherapy related to clinical outcome in patients with oropharyngeal squamous cell carcinoma. Results Due to the radiotherapy being largely successful, the sample sizes of non-responder groups were small, and therefore it was not possible to properly assess the predictive nature of OE-MRI. The tumour R1 increased in some patients while decreasing in others, in a pattern that was overall consistent with the underlying OE-MRI theory and previously reported tumour OE-MRI responses. In addition, we discuss some practical challenges faced when integrating this technique into a clinical trial, with the aim that sharing this is helpful to researchers planning to use OE-MRI in future clinical studies. Conclusion Altogether, these results suggest that further clinical OE-MRI studies to assess hypoxia and radiotherapy response are worth pursuing, and that there is important work to be done to improve the robustness of the OE-MRI technique in human applications in order for it to be useful as a widespread clinical technique.
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Affiliation(s)
- Emma Bluemke
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK,Corresponding author at: Old Road Campus Research Building, University of Oxford, Headington, Oxford OX3 7DQ, UK.
| | - Ambre Bertrand
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK
| | - Kwun-Ye Chu
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, UK,Radiotherapy Department, Oxford University Hospitals NHS Foundation Trust, UK
| | - Nigar Syed
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, UK
| | - Andrew G. Murchison
- Department of Radiology, Oxford University Hospitals NHS Foundation Trust, UK
| | - Rosie Cooke
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, UK,Radiotherapy Department, Oxford University Hospitals NHS Foundation Trust, UK
| | - Tessa Greenhalgh
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, UK,University Hospital Southampton NHS Foundation Trust, UK
| | | | | | - Nia Taylor
- Department of Radiology, Oxford University Hospitals NHS Foundation Trust, UK
| | - Ketan Shah
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, UK,Radiotherapy Department, Oxford University Hospitals NHS Foundation Trust, UK
| | - Fergus Gleeson
- Department of Radiology, Oxford University Hospitals NHS Foundation Trust, UK
| | - Daniel Bulte
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK
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Geier ET, Prisk GK, Sá RC. Measuring short-term changes in specific ventilation using dynamic specific ventilation imaging. J Appl Physiol (1985) 2022; 132:1370-1378. [PMID: 35482322 DOI: 10.1152/japplphysiol.00652.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Specific ventilation imaging (SVI) measures the spatial distribution of specific ventilation (SV) in the lung with MRI by using inhaled oxygen as a contrast agent. Because of the inherently low signal to noise ratio in the technique, multiple switches between inspiring air and O2 are utilized, and the high spatial resolution SV distribution determined as an average over the entire imaging period (~20 minutes). We hypothesized that a trade-off between spatial and temporal resolution could allow imaging at a higher temporal resolution, at the cost of a coarser, yet acceptable, spatial resolution. The appropriate window length and spatial resolution compromise was determined by generating synthetic data with signal- and contrast-to-noise characteristics reflective of that in previously published experimental data, with a known and unchanging distribution of SV, and showed that acceptable results could be obtained in an imaging period of ~7 minutes (80 breaths), with a spatial resolution of ~1cm3. Previously published data were then reanalyzed. The average heterogeneity of the temporally resolved maps of SV were not different to the previous overall analysis, however the temporally resolved maps were less effective at detecting the amount of bronchoconstriction resulting from methacholine administration. The results further indicated that the initial response to inhaled methacholine and subsequent inhalation of albuterol were largely complete within ~22 minutes and ~9 minutes respectively, although there was a tendency for an ongoing developing effect in both cases. These results suggest that it is feasible to use a shortened SVI protocol, with a modest sacrifice in spatial resolution, in order to measure temporally dynamic processes.
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Affiliation(s)
- Eric T Geier
- Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Gordon Kim Prisk
- Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Rui Carlos Sá
- Department of Medicine, University of California, San Diego, San Diego, CA, United States
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Using Variable Flip Angle (VFA) and Modified Look-Locker Inversion Recovery (MOLLI) T1 mapping in clinical OE-MRI. Magn Reson Imaging 2022; 89:92-99. [PMID: 35341905 DOI: 10.1016/j.mri.2022.03.001] [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: 11/01/2021] [Revised: 03/16/2022] [Accepted: 03/19/2022] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND PURPOSE The imaging technique known as Oxygen-Enhanced MRI is under development as a noninvasive technique for imaging hypoxia in tumours and pulmonary diseases. While promising results have been shown in preclinical experiments, clinical studies have mentioned experiencing difficulties with patient motion, image registration, and the limitations of single-slice images compared to 3D volumes. As clinical studies begin to assess feasibility of using OE-MRI in patients, it is important for researchers to communicate about the practical challenges experienced when using OE-MRI on patients to help the technique advance. MATERIALS AND METHODS We report on our experience with using two types of T1 mapping (MOLLI and VFA) for a recently completed OE-MRI clinical study on oropharyngeal squamous cell carcinoma. RESULTS We report: (1) the artefacts and practical difficulties encountered in this study; (2) the difference in estimated T1 from each method used - the VFA T1 estimation was higher than the MOLLI estimation by 27% on average; (3) the standard deviation within the tumour ROIs - there was no significant difference in the standard deviation seen within the tumour ROIs from the VFA versus MOLLI; and (4) the OE-MRI response collected from either method. Lastly, we collated the MRI acquisition details from over 45 relevant manuscripts as a convenient reference for researchers planning future studies. CONCLUSION We have reported our practical experience from an OE-MRI clinical study, with the aim that sharing this is helpful to researchers planning future studies. In this study, VFA was a more useful technique for using OE-MRI in tumours than MOLLI T1 mapping.
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Bhattacharya I, Ramasawmy R, Javed A, Lowery M, Henry J, Mancini C, Machado T, Jones A, Julien-Williams P, Lederman RJ, Balaban RS, Chen MY, Moss J, Campbell-Washburn AE. Assessment of Lung Structure and Regional Function Using 0.55 T MRI in Patients With Lymphangioleiomyomatosis. Invest Radiol 2022; 57:178-186. [PMID: 34652290 PMCID: PMC9926400 DOI: 10.1097/rli.0000000000000832] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Contemporary lower-field magnetic resonance imaging (MRI) may offer advantages for lung imaging by virtue of the improved field homogeneity. The aim of this study was to evaluate the utility of lower-field MRI for combined morphologic imaging and regional lung function assessment. We evaluate low-field MRI in patients with lymphangioleiomyomatosis (LAM), a rare lung disease associated with parenchymal cysts and respiratory failure. MATERIALS AND METHODS We performed lung imaging on a prototype low-field (0.55 T) MRI system in 65 patients with LAM. T2-weighted imaging was used for assessment of lung morphology and to derive cyst scores, the percent of lung parenchyma occupied by cysts. Regional lung function was assessed using oxygen-enhanced MRI with breath-held ultrashort echo time imaging and inhaled 100% oxygen as a T1-shortening MR contrast agent. Measurements of percent signal enhancement from oxygen inhalation and percentage of lung with low oxygen enhancement, indicating functional deficits, were correlated with global pulmonary function test measurements taken within 2 days. RESULTS We were able to image cystic abnormalities using T2-weighted MRI in this patient population and calculate cyst score with strong correlation to computed tomography measurements (R = 0.86, P < 0.0001). Oxygen-enhancement maps demonstrated regional deficits in lung function of patients with LAM. Heterogeneity of oxygen enhancement between cysts was observed within individual patients. The percent low-enhancement regions showed modest, but significant, correlation with FEV1 (R = -0.37, P = 0.007), FEV1/FVC (R = -0.33, P = 0.02), and cyst score (R = 0.40, P = 0.02). The measured arterial blood ΔT1 between normoxia and hyperoxia, used as a surrogate for dissolved oxygen in blood, correlated with DLCO (R = -0.28, P = 0.03). CONCLUSIONS Using high-performance 0.55 T MRI, we were able to perform simultaneous imaging of pulmonary structure and regional function in patients with LAM.
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Affiliation(s)
- Ipshita Bhattacharya
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Rajiv Ramasawmy
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Ahsan Javed
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Margaret Lowery
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Jennifer Henry
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Christine Mancini
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Tania Machado
- Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Amanda Jones
- Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Patricia Julien-Williams
- Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Robert J Lederman
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Robert S Balaban
- Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Marcus Y Chen
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Joel Moss
- Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Adrienne E Campbell-Washburn
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
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11
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Niedbalski PJ, Choi J, Hall CS, Castro M. Imaging in Asthma Management. Semin Respir Crit Care Med 2022; 43:613-626. [PMID: 35211923 DOI: 10.1055/s-0042-1743289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Asthma is a heterogeneous disease characterized by chronic airway inflammation that affects more than 300 million people worldwide. Clinically, asthma has a widely variable presentation and is defined based on a history of respiratory symptoms alongside airflow limitation. Imaging is not needed to confirm a diagnosis of asthma, and thus the use of imaging in asthma has historically been limited to excluding alternative diagnoses. However, significant advances continue to be made in novel imaging methodologies, which have been increasingly used to better understand respiratory impairment in asthma. As a disease primarily impacting the airways, asthma is best understood by imaging methods with the ability to elucidate airway impairment. Techniques such as computed tomography, magnetic resonance imaging with gaseous contrast agents, and positron emission tomography enable assessment of the small airways. Others, such as optical coherence tomography and endobronchial ultrasound enable high-resolution imaging of the large airways accessible to bronchoscopy. These imaging techniques are providing new insights in the pathophysiology and treatments of asthma and are poised to impact the clinical management of asthma.
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Affiliation(s)
- Peter J Niedbalski
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas
| | - Jiwoong Choi
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas
| | - Chase S Hall
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas
| | - Mario Castro
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas
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12
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Abstract
Childhood interstitial lung disease (ChILD) is an umbrella term encompassing a diverse group of diffuse lung diseases affecting infants and children. Although the timely and accurate diagnosis of ChILD is often challenging, it is optimally achieved through the multidisciplinary integration of imaging findings with clinical data, genetics, and potentially lung biopsy. This article reviews the definition and classification of ChILD; the role of imaging, pathology, and genetics in ChILD diagnosis; treatment options; and future goals. In addition, a practical approach to ChILD imaging based on the latest available research and the characteristic imaging appearance of ChILD entities are presented.
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Bhattacharya I, Ramasawmy R, Javed A, Chen MY, Benkert T, Majeed W, Lederman RJ, Moss J, Balaban RS, Campbell-Washburn AE. Oxygen-enhanced functional lung imaging using a contemporary 0.55 T MRI system. NMR IN BIOMEDICINE 2021; 34:e4562. [PMID: 34080253 PMCID: PMC8377594 DOI: 10.1002/nbm.4562] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 05/14/2023]
Abstract
The purpose of this study was to evaluate oxygen-enhanced pulmonary imaging at 0.55 T with 3D stack-of-spirals ultrashort-TE (UTE) acquisition. Oxygen-enhanced pulmonary MRI offers the measurement of regional lung ventilation and perfusion using inhaled oxygen as a contrast agent. Low-field MRI systems equipped with contemporary hardware can provide high-quality structural lung imaging by virtue of the prolonged T2 *. Fortuitously, the T1 relaxivity of oxygen increases at lower field strengths, which is expected to improve the sensitivity of oxygen-enhanced lung MRI. We implemented a breath-held T1 -weighted 3D stack-of-spirals UTE acquisition with a 7 ms spiral-out readout. Measurement repeatability was assessed using five repetitions of oxygen-enhanced lung imaging in healthy volunteers (n = 7). The signal intensity at both normoxia and hyperoxia was strongly dependent on lung tissue density modulated by breath-hold volume during the five repetitions. A voxel-wise correction for lung tissue density improved the repeatability of percent signal enhancement maps (coefficient of variation = 34 ± 16%). Percent signal enhancement maps were compared in 15 healthy volunteers and 10 patients with lymphangioleiomyomatosis (LAM), a rare cystic disease known to reduce pulmonary function. We measured a mean percent signal enhancement of 9.0 ± 3.5% at 0.55 T in healthy volunteers, and reduced signal enhancement in patients with LAM (5.4 ± 4.8%, p = 0.02). The heterogeneity, estimated by the percent of lung volume exhibiting low enhancement, was significantly increased in patients with LAM compared with healthy volunteers (11.1 ± 6.0% versus 30.5 ± 13.1%, p = 0.01), illustrating the capability to measure regional functional deficits.
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Affiliation(s)
- Ipshita Bhattacharya
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Rajiv Ramasawmy
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Ahsan Javed
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Marcus Y Chen
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Thomas Benkert
- Siemens Healthcare GmbH, Henkestraße 127, 91052 Erlangen, Germany
| | - Waqas Majeed
- Siemens Medical Solutions USA Inc., 40 Liberty Boulevard, Malvern PA, 1935 USA
| | - Robert J Lederman
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Joel Moss
- Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
| | - Robert S Balaban
- Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood I nstitute, National Institutes of Health, Bethesda MD, USA 20892
| | - Adrienne E Campbell-Washburn
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda MD, USA 20892
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14
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Zhao F, Zheng L, Shan F, Dai Y, Shen J, Yang S, Shi Y, Xue K, Zhang Z. Evaluation of pulmonary ventilation in COVID-19 patients using oxygen-enhanced three-dimensional ultrashort echo time MRI: a preliminary study. Clin Radiol 2021; 76:391.e33-391.e41. [PMID: 33712292 PMCID: PMC7906509 DOI: 10.1016/j.crad.2021.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 02/17/2021] [Indexed: 01/15/2023]
Abstract
AIM To evaluate the lung function of coronavirus disease 2019 (COVID-19) patients using oxygen-enhanced (OE) ultrashort echo time (UTE) MRI. MATERIALS AND METHODS Forty-nine patients with COVID-19 were included in the study. The OE-MRI was based on a respiratory-gated three-dimensional (3D) radial UTE sequence. For each patient, the percent signal enhancement (PSE) map was calculated using the expression PSE = (S100% – S21%)/S21%, where S21% and S100% are signals acquired during room air and 100% oxygen inhalation, respectively. Agreement of lesion detectability between UTE-MRI and computed tomography (CT) was performed using the kappa test. The Mann–Whitney U-test was used to evaluate the difference in the mean PSE between mild-type COVID-19 and common-type COVID-19. Spearman's test was used to assess the relationship between lesion mean PSE and lesion size. Furthermore, the Mann–Whitney U-test was used to evaluate the difference in region of interest (ROI) mean PSE between normal pulmonary parenchyma and lesions. The Kruskal–Wallis test was applied to test the difference in the mean PSE between different lesion types. RESULTS CT and UTE-MRI reached good agreement in lesion detectability. Ventilation measures in mild-type patients (5.3 ± 5.5%) were significantly different from those in common-type patients (3 ± 3.9%). Besides, there was no significant correlation between lesion mean PSE and lesion size. The mean PSE of COVID-19 lesions (3.2 ± 4.9%) was significantly lower than that of the pulmonary parenchyma (5.4 ± 3.9%). No significant difference was found among different lesion types. CONCLUSION OE-UTE-MRI could serve as a promising method for the assessment of lung function or treatment management of COVID-19 patients.
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Affiliation(s)
- F Zhao
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China; Department of Radiology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - L Zheng
- MR Collaboration, Central Research Institute, United Imaging Healthcare, Shanghai 201800, China
| | - F Shan
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Y Dai
- MR Collaboration, Central Research Institute, United Imaging Healthcare, Shanghai 201800, China
| | - J Shen
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - S Yang
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Y Shi
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - K Xue
- MR Collaboration, Central Research Institute, United Imaging Healthcare, Shanghai 201800, China
| | - Z Zhang
- Department of Radiology, Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China; Department of the Principal's Office, Fudan University, Shanghai 200433, China.
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15
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Voskrebenzev A, Vogel-Claussen J. Proton MRI of the Lung: How to Tame Scarce Protons and Fast Signal Decay. J Magn Reson Imaging 2020; 53:1344-1357. [PMID: 32166832 DOI: 10.1002/jmri.27122] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/20/2020] [Accepted: 02/20/2020] [Indexed: 12/19/2022] Open
Abstract
Pulmonary proton MRI techniques offer the unique possibility of assessing lung function and structure without the requirement for hyperpolarization or dedicated hardware, which is mandatory for multinuclear acquisition. Five popular approaches are presented and discussed in this review: 1) oxygen enhanced (OE)-MRI; 2) arterial spin labeling (ASL); 3) Fourier decomposition (FD) MRI and other related methods including self-gated noncontrast-enhanced functional lung (SENCEFUL) MR and phase-resolved functional lung (PREFUL) imaging; 4) dynamic contrast-enhanced (DCE) MRI; and 5) ultrashort TE (UTE) MRI. While DCE MRI is the most established and well-studied perfusion measurement, FD MRI offers a free-breathing test without any contrast agent and is predestined for application in patients with renal failure or with low compliance. Additionally, FD MRI and related methods like PREFUL and SENCEFUL can act as an ionizing radiation-free V/Q scan, since ventilation and perfusion information is acquired simultaneously during one scan. For OE-MRI, different concentrations of oxygen are applied via a facemask to assess the regional change in T1 , which is caused by the paramagnetic property of oxygen. Since this change is governed by a combination of ventilation, diffusion, and perfusion, a compound functional measurement can be achieved with OE-MRI. The known problem of fast T2 * decay of the lung parenchyma leading to a low signal-to-noise ratio is bypassed by the UTE acquisition strategy. Computed tomography (CT)-like images allow the assessment of lung structure with high spatial resolution without ionizing radiation. Despite these different branches of proton MRI, common trends are evident among pulmonary proton MRI: 1) free-breathing acquisition with self-gating; 2) application of UTE to preserve a stronger parenchymal signal; and 3) transition from 2D to 3D acquisition. On that note, there is a visible convergence of the different methods and it is not difficult to imagine that future methods will combine different aspects of the presented methods.
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Affiliation(s)
- Andreas Voskrebenzev
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Jens Vogel-Claussen
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
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16
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Zha W, Fain SB, Schiebler ML, Nagle SK, Liu F. Deep convolutional neural networks with multiplane consensus labeling for lung function quantification using UTE proton MRI. J Magn Reson Imaging 2019; 50:1169-1181. [PMID: 30945385 PMCID: PMC7039686 DOI: 10.1002/jmri.26734] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/15/2019] [Accepted: 03/15/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Ultrashort echo time (UTE) proton MRI has gained popularity for assessing lung structure and function in pulmonary imaging; however, the development of rapid biomarker extraction and regional quantification has lagged behind due to labor-intensive lung segmentation. PURPOSE To evaluate a deep learning (DL) approach for automated lung segmentation to extract image-based biomarkers from functional lung imaging using 3D radial UTE oxygen-enhanced (OE) MRI. STUDY TYPE Retrospective study aimed to evaluate a technical development. POPULATION Forty-five human subjects, including 16 healthy volunteers, 5 asthma, and 24 patients with cystic fibrosis. FIELD STRENGTH/SEQUENCE 1.5T MRI, 3D radial UTE (TE = 0.08 msec) sequence. ASSESSMENT Two 3D radial UTE volumes were acquired sequentially under normoxic (21% O2 ) and hyperoxic (100% O2 ) conditions. Automated segmentation of the lungs using 2D convolutional encoder-decoder based DL method, and the subsequent functional quantification via adaptive K-means were compared with the results obtained from the reference method, supervised region growing. STATISTICAL TESTS Relative to the reference method, the performance of DL on volumetric quantification was assessed using Dice coefficient with 95% confidence interval (CI) for accuracy, two-sided Wilcoxon signed-rank test for computation time, and Bland-Altman analysis on the functional measure derived from the OE images. RESULTS The DL method produced strong agreement with supervised region growing for the right (Dice: 0.97; 95% CI = [0.96, 0.97]; P < 0.001) and left lungs (Dice: 0.96; 95% CI = [0.96, 0.97]; P < 0.001). The DL method averaged 46 seconds to generate the automatic segmentations in contrast to 1.93 hours using the reference method (P < 0.001). Bland-Altman analysis showed nonsignificant intermethod differences of volumetric (P ≥ 0.12) and functional measurements (P ≥ 0.34) in the left and right lungs. DATA CONCLUSION DL provides rapid, automated, and robust lung segmentation for quantification of regional lung function using UTE proton MRI. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:1169-1181.
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Affiliation(s)
- Wei Zha
- Department of Medical Physics, University of Wisconsin-Madison
| | - Sean B. Fain
- Department of Medical Physics, University of Wisconsin-Madison
- Department of Radiology, University of Wisconsin-Madison
- Department of Biomedical Engineering, University of Wisconsin-Madison
| | | | - Scott K. Nagle
- Department of Medical Physics, University of Wisconsin-Madison
- Department of Radiology, University of Wisconsin-Madison
- Department of Pediatrics, University of Wisconsin-Madison
| | - Fang Liu
- Department of Radiology, University of Wisconsin-Madison
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17
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Torres L, Kammerman J, Hahn AD, Zha W, Nagle SK, Johnson K, Sandbo N, Meyer K, Schiebler M, Fain SB. "Structure-Function Imaging of Lung Disease Using Ultrashort Echo Time MRI". Acad Radiol 2019; 26:431-441. [PMID: 30658930 DOI: 10.1016/j.acra.2018.12.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 12/19/2018] [Accepted: 12/21/2018] [Indexed: 12/14/2022]
Abstract
RATIONALE AND OBJECTIVES The purpose of this review is to acquaint the reader with recent advances in ultrashort echo time (UTE) magnetic resonance imaging (MRI) of the lung and its implications for pulmonary MRI when used in conjunction with functional MRI technique. MATERIALS AND METHODS We provide an overview of recent technical advances of UTE and explore the advantages of combined structure-function pulmonary imaging in the context of restrictive and obstructive pulmonary diseases such as idiopathic pulmonary fibrosis (IPF) and cystic fibrosis (CF). RESULTS UTE MRI clearly shows the lung parenchymal changes due to IPF and CF. The use of UTE MRI, in conjunction with established functional lung MRI in chronic lung diseases, will serve to mitigate the need for computed tomography in children. CONCLUSION Current limitations of UTE MRI include long scan times, poor delineation of thin-walled structures (e.g. cysts and reticulation) due to limited spatial resolution, low signal to noise ratio, and imperfect motion compensation. Despite these limitations, UTE MRI can now be considered as an alternative to multidetector computed tomography for the longitudinal follow-up of the morphological changes from lung diseases in neonates, children, and young adults, particularly as a complement to the unique functional capabilities of MRI.
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18
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Zha W, Nagle SK, Cadman RV, Schiebler ML, Fain SB. Three-dimensional Isotropic Functional Imaging of Cystic Fibrosis Using Oxygen-enhanced MRI: Comparison with Hyperpolarized 3He MRI. Radiology 2018; 290:229-237. [PMID: 30351258 DOI: 10.1148/radiol.2018181148] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Purpose To compare the performance of three-dimensional radial ultrashort echo time (UTE) oxygen-enhanced (OE) MRI with that of hyperpolarized helium 3 (3He) MRI with respect to quantitative ventilation measurements in patients with cystic fibrosis (CF). Materials and Methods In this prospective study conducted from June 2013 to May 2015, 25 participants with CF aged 10-55 years (14 male; age range, 13-55 years; 11 female; age range, 10-37 years) successfully underwent pulmonary function tests, hyperpolarized 3He MRI, and OE MRI. OE MRI used two sequential 3.5-minute normoxic and hyperoxic steady-state free-breathing UTE acquisitions. Seven participants underwent imaging at two separate examinations 1-2 weeks apart to assess repeatability. Regional ventilation was quantified as ventilation defect percentage (VDP) individually from OE MRI and hyperpolarized 3He MRI by using the same automated quantification tool. Bland-Altman analysis, intraclass correlation coefficient (ICC), Spearman correlation coefficient, and Wilcoxon signed-rank test were used to evaluate repeatability. Results In all 24 participants, the global VDP measurements from either OE MRI (ρ = -0.66, P < .001) or hyperpolarized 3He MRI (ρ = -0.75, P < .001) were significantly correlated with the percentage predicted forced expiratory volume in 1 second. VDP reported at OE MRI was 5.0% smaller than (P = .014) but highly correlated with (ρ = 0.78, P < .001) VDP reported at hyperpolarized 3He MRI. Both OE MRI-based VDP and hyperpolarized 3He MRI-based VDP demonstrated good repeatability (ICC = 0.91 and 0.95, respectively; P ≤ .001). Conclusion In lungs with cystic fibrosis, ultrashort echo time oxygen-enhanced MRI showed similar performance compared with hyperpolarized 3He MRI for quantitative measures of ventilation defects and their repeatability. © RSNA, 2018 Online supplemental material is available for this article.
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Affiliation(s)
- Wei Zha
- From the Departments of Medical Physics (W.Z., S.K.N., R.V.C., S.B.F.), Radiology (S.K.N., M.L.S., S.B.F.), Pediatrics (S.K.N.), and Biomedical Engineering (S.B.F.), University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, 1111 Highland Ave, Room 2492, Madison, WI 53792
| | - Scott K Nagle
- From the Departments of Medical Physics (W.Z., S.K.N., R.V.C., S.B.F.), Radiology (S.K.N., M.L.S., S.B.F.), Pediatrics (S.K.N.), and Biomedical Engineering (S.B.F.), University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, 1111 Highland Ave, Room 2492, Madison, WI 53792
| | - Robert V Cadman
- From the Departments of Medical Physics (W.Z., S.K.N., R.V.C., S.B.F.), Radiology (S.K.N., M.L.S., S.B.F.), Pediatrics (S.K.N.), and Biomedical Engineering (S.B.F.), University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, 1111 Highland Ave, Room 2492, Madison, WI 53792
| | - Mark L Schiebler
- From the Departments of Medical Physics (W.Z., S.K.N., R.V.C., S.B.F.), Radiology (S.K.N., M.L.S., S.B.F.), Pediatrics (S.K.N.), and Biomedical Engineering (S.B.F.), University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, 1111 Highland Ave, Room 2492, Madison, WI 53792
| | - Sean B Fain
- From the Departments of Medical Physics (W.Z., S.K.N., R.V.C., S.B.F.), Radiology (S.K.N., M.L.S., S.B.F.), Pediatrics (S.K.N.), and Biomedical Engineering (S.B.F.), University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, 1111 Highland Ave, Room 2492, Madison, WI 53792
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19
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Abstract
Asthma is increasingly recognised as a heterogeneous group of diseases with similar clinical presentations rather than a singular disease entity. Asthma was historically categorised by clinical symptoms; however, newer methods of subgrouping, describing and categorising the disease have sub-defined asthma. These sub-definitions are intermittently called phenotypes or endotypes, but the real meanings of these words are poorly understood. Novel treatments are currently and increasingly available, partly in the monoclonal antibody environment, and also some physical therapies (bronchial thermoplasty), but additionally small molecules are not far away from clinical practice. Understanding the disease pathogenesis and the mechanism of action more completely may enable identification of treatable traits, biomarkers, mediators and modifiable therapeutic targets. However, there remains a danger that clinicians become preoccupied with the concept of endotypes and biomarkers, ignoring therapies that are hugely effective but have no companion biomarker. This review discusses our understanding of the concept of phenotypes and endotypes in appreciating and managing the heterogeneous condition that is asthma. We consider the role of functional imaging, physiology, blood-, sputum- and breath-based biomarkers and clinical manifestations that could be used to produce a personalised asthma profile, with implications on prognosis, pathophysiology and most importantly specific therapeutic responses. With the advent of increasing numbers of biological therapies and other interventional options such as bronchial thermoplasty, the importance of targeting expensive therapies to patients with the best chance of clinical response has huge health economic importance.
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Affiliation(s)
- Katrina Dean
- University Hospital South Manchester, Manchester, UK
| | - Robert Niven
- Manchester Academic Health Science Centre, The University of Manchester and University Hospital South Manchester, Manchester, UK.
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20
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Martini K, Gygax CM, Benden C, Morgan AR, Parker GJM, Frauenfelder T. Volumetric dynamic oxygen-enhanced MRI (OE-MRI): comparison with CT Brody score and lung function in cystic fibrosis patients. Eur Radiol 2018; 28:4037-4047. [PMID: 29654559 DOI: 10.1007/s00330-018-5383-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/11/2017] [Accepted: 02/12/2018] [Indexed: 01/04/2023]
Abstract
OBJECTIVES To demonstrate, in patients with cystic fibrosis (CF), the correlation between three-dimensional dynamic oxygen-enhanced magnetic resonance imaging (OE-MRI) measurements and computed tomography Brody score (CF-CT) and lung function testing (LFT). METHODS Twenty-one patients (median age, 25 years; female, n = 8) with a range of CF lung disease and five healthy volunteers (median age, 31 years; female, n = 2) underwent OE-MRI performed on a 1.5-T MRI scanner. Coronal volumes were acquired while patients alternately breathed room air and 100% oxygen. Pre-oxygen T1 was measured. Dynamic series of T1-weighted volumes were then obtained while breathing oxygen. T1-parameter maps were generated and the following OE-MRI parameters were measured: oxygen uptake (ΔPO2max), wash-in time and wash-out time. High-resolution CT and LFT were performed. The relationship between CF-CT, LFT and OE-MRI parameters were evaluated using Pearson correlation for the whole lung and regionally. RESULTS Mean CF-CT was 24.1±17.1. Mean ΔPO2max and mean wash-in as well as skewness of wash-out showed significant correlation with CF-CT (ΔPO2max: r = -0.741, p < 0.001; mean wash-in: r = 0.501, p = 0.017; skewness of wash-out: r = 0.597, p = 0.001). There was significant correlation for the whole lung and regionally between LFT parameters and OE-MR (ΔPO2max: r = 0.718, p < 0.001; wash-in: r = -0.576, p = 0.003; wash-out skewness: r = -0.552, p = 0.004). CONCLUSIONS Functional lung imaging using OE-MRI has the capability to assess the severity of CF lung disease and shows a significant correlation with LFT and CF-CT. KEY POINTS • Oxygen-enhanced MRI might play a future role in evaluation and follow-up of cystic fibrosis. • Heterogeneity of parameter maps reflects localised functional impairment in cystic fibrosis. • Avoidance of cumulative radiation burden in CF is feasible using OE-MRI.
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Affiliation(s)
- K Martini
- Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland.
- University of Zurich, Zurich, Switzerland.
| | - C M Gygax
- University of Zurich, Zurich, Switzerland
| | - C Benden
- Division of Pulmonology, University Hospital Zurich, Zurich, Switzerland
| | - A R Morgan
- Bioxydyn Limited, Manchester, UK
- Centre for Imaging Science, The University of Manchester, Manchester, UK
| | - G J M Parker
- Bioxydyn Limited, Manchester, UK
- Centre for Imaging Science, The University of Manchester, Manchester, UK
| | - T Frauenfelder
- Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
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21
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Zha W, Kruger SJ, Johnson KM, Cadman RV, Bell LC, Liu F, Hahn AD, Evans MD, Nagle SK, Fain SB. Pulmonary ventilation imaging in asthma and cystic fibrosis using oxygen-enhanced 3D radial ultrashort echo time MRI. J Magn Reson Imaging 2017; 47:1287-1297. [PMID: 29086454 DOI: 10.1002/jmri.25877] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 10/10/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND A previous study demonstrated the feasibility of using 3D radial ultrashort echo time (UTE) oxygen-enhanced MRI (UTE OE-MRI) for functional imaging of healthy human lungs. The repeatability of quantitative measures from UTE OE-MRI needs to be established prior to its application in clinical research. PURPOSE To evaluate repeatability of obstructive patterns in asthma and cystic fibrosis (CF) with UTE OE-MRI with isotropic spatial resolution and full chest coverage. STUDY TYPE Volunteer and patient repeatability. POPULATION Eighteen human subjects (five asthma, six CF, and seven normal subjects). FIELD STRENGTH/SEQUENCE Respiratory-gated free-breathing 3D radial UTE (80 μs) sequence at 1.5T. ASSESSMENT Two 3D radial UTE volumes were acquired sequentially under normoxic and hyperoxic conditions. A subset of subjects underwent repeat acquisitions on either the same day or ≤15 days apart. Asthma and CF subjects also underwent spirometry. A workflow including deformable registration and retrospective lung density correction was used to compute 3D isotropic percent signal enhancement (PSE) maps. Median PSE (MPSE) and ventilation defect percent (VDP) of the lung were measured from the PSE map. STATISTICAL TESTS The relations between MPSE, VDP, and spirometric measures were assessed using Spearman correlations. The test-retest repeatability was evaluated using Bland-Altman analysis and intraclass correlation coefficients (ICC). RESULTS Ventilation measures in normal subjects (MPSE = 8.0%, VDP = 3.3%) were significantly different from those in asthma (MPSE = 6.0%, P = 0.042; VDP = 21.7%, P = 0.018) and CF group (MPSE = 4.5%, P = 0.0006; VDP = 27.2%, P = 0.002). MPSE correlated significantly with forced expiratory lung volume in 1 second percent predicted (ρ = 0.72, P = 0.017). The ICC of the test-retest VDP and MPSE were both ≥0.90. In all subject groups, an anterior/posterior gradient was observed with higher MPSE and lower VDP in the posterior compared to anterior regions (P ≤ 0.0021 for all comparisons). DATA CONCLUSION 3D radial UTE OE-MRI supports quantitative differentiation of diseased vs. healthy lungs using either whole lung VDP or MPSE with excellent test-retest repeatability. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1287-1297.
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Affiliation(s)
- Wei Zha
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Stanley J Kruger
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kevin M Johnson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Robert V Cadman
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Laura C Bell
- Division of Imaging Research, Barrow Neurological Institute, Phoenix, Arizona, USA
| | - Fang Liu
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Andrew D Hahn
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Michael D Evans
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Scott K Nagle
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Pediatrics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sean B Fain
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
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22
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Capaldi DP, Sheikh K, Eddy RL, Guo F, Svenningsen S, Nair P, McCormack DG, Parraga G. Free-breathing Functional Pulmonary MRI: Response to Bronchodilator and Bronchoprovocation in Severe Asthma. Acad Radiol 2017; 24:1268-1276. [PMID: 28551402 DOI: 10.1016/j.acra.2017.04.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/05/2017] [Accepted: 04/08/2017] [Indexed: 02/03/2023]
Abstract
RATIONALE AND OBJECTIVES Ventilation heterogeneity is a hallmark feature of asthma. Our objective was to evaluate ventilation heterogeneity in patients with severe asthma, both pre- and post-salbutamol, as well as post-methacholine (MCh) challenge using the lung clearance index, free-breathing pulmonary 1H magnetic resonance imaging (FDMRI), and inhaled-gas MRI ventilation defect percent (VDP). MATERIALS AND METHODS Sixteen severe asthmatics (49 ± 10 years) provided written informed consent to an ethics board-approved protocol. Spirometry, plethysmography, and multiple breath nitrogen washout to measure the lung clearance index were performed during a single visit within 15 minutes of MRI. Inhaled-gas MRI and FDMRI were performed pre- and post-bronchodilator to generate VDP. For asthmatics with forced expiratory volume in 1 second (FEV1) >70%predicted, MRI was also performed before and after MCh challenge. Wilcoxon signed-rank tests, Spearman correlations, and a repeated-measures analysis of variance were performed. RESULTS Hyperpolarized 3He (P = .02) and FDMRI (P = .02) VDP significantly improved post-salbutamol and for four asthmatics who could perform MCh (n = 4). 3He and FDMRI VDP significantly increased at the provocative concentration of MCh, resulting in a 20% decrease in FEV1 (PC20) and decreased post-bronchodilator (P = .02), with a significant difference between methods (P = .01). FDMRI VDP was moderately correlated with 3He VDP (ρ = .61, P = .01), but underestimated VDP relative to 3He VDP (-6 ± 9%). Whereas 3He MRI VDP was significantly correlated with the lung clearance index, FDMRI was not (ρ = .49, P = .06). CONCLUSIONS FDMRI VDP generated in free-breathing asthmatic patients was correlated with static inspiratory breath-hold 3He MRI VDP but underestimated VDP relative to 3He MRI VDP. Although less sensitive to salbutamol and MCh, FDMRI VDP may be considered for asthma patient evaluations at centers without inhaled-gas MRI.
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23
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Wang K, Pan T, Yang H, Ruan W, Zhong J, Wu G, Zhou X. Assessment of pulmonary microstructural changes by hyperpolarized 129Xe diffusion-weighted imaging in an elastase-instilled rat model of emphysema. J Thorac Dis 2017; 9:2572-2578. [PMID: 28932564 DOI: 10.21037/jtd.2017.08.39] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND The purpose of this study was to explore the feasibility of hyperpolarized 129Xe diffusion-weighted imaging (DWI) for the evaluation of pulmonary microstructural changes in the presence of pancreatic porcine elastase (PPE)-induced pulmonary emphysema rat model. METHODS Sixteen male Sprague-Dawley (SD) rats were randomly divided into two groups, the emphysema model group and control group. Experimental emphysematous models were made by instilling elastase into rat lungs of model group, the control group were instilled with isodose saline. Hyperpolarized 129Xe magnetic resonance imaging (MRI) and histology were performed in all 16 rats after 30 days. DWIs were performed on a Bruker 7.0 T micro MRI, and the apparent diffusion coefficients (ADCs) were measured in all rats. Mean linear intercepts (MLIs) of pulmonary alveoli were measured on histology. The statistical analyses were performed about the correlation between the mean ADC of hyperpolarized 129Xe in the whole lung and MLI of pulmonary histology metric. RESULTS The pulmonary emphysematous model was successfully confirmed by the histology and all scans were also successful. The ADC value of 129Xe in the model group (0.0313±0.0005 cm2/s) was significantly increased compared with that of the control group (0.0288±0.0007 cm2/s, P<0.0001). Morphological differences such as MLI of pulmonary alveoli were observed between the two groups, the MLI of pulmonary alveoli in model group significantly increased (91±5 µm) than that of control group (50±3 µm, P<0.0001). Furthermore, the ADCs was moderately correlated with MLIs (r=0.724, P<0.01). CONCLUSIONS These results indicate that 129Xe ADC value can quantitatively reflect the alveolar space enlargement and it is a promising biomarker for the detection of pulmonary emphysema.
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Affiliation(s)
- Ke Wang
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Ting Pan
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Hao Yang
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Weiwei Ruan
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jianping Zhong
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Guangyao Wu
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Xin Zhou
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
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24
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Bauman G, Pusterla O, Santini F, Bieri O. Dynamic and steady-state oxygen-dependent lung relaxometry using inversion recovery ultra-fast steady-state free precession imaging at 1.5 T. Magn Reson Med 2017; 79:839-845. [PMID: 28520198 DOI: 10.1002/mrm.26739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/06/2017] [Accepted: 04/06/2017] [Indexed: 12/31/2022]
Abstract
PURPOSE To demonstrate the feasibility of oxygen-dependent relaxometry in human lung using an inversion recovery ultra-fast steady-state free precession (IR-ufSSFP) technique. METHODS Electrocardiogram-triggered pulmonary relaxometry with IR-ufSSFP was performed in 7 healthy human subjects at 1.5 T. The data were acquired under both normoxic and hyperoxic conditions. In a single breath-hold of less than 9 seconds, 30 transient state IR-ufSSFP images were acquired, yielding longitudinal (T1) and transversal (T2) relaxometry parameter maps using voxel-wise nonlinear fitting. Possible spatial misalignments between consecutive IR-ufSSFP parameter maps were corrected using elastic image registration. Furthermore, dynamic relaxometry oxygen wash-in and wash-out scans were performed in one volunteer. From this, T1 -related wash-in and wash-out time constants (τwi , τwo ) were calculated voxel-wise on registered maps using an exponential fitting model. RESULTS For healthy lung, observed T1 values were 1399 ± 77 and 1290 ± 76 ms under normoxic and hyperoxic conditions, respectively. Oxygen-related reduction of T1 was statistically significant in every volunteer. No statistically significant change, however, was observed in T2, with normoxic and hyperoxic T2 values of 55 ± 16 and 56 ± 17 ms, respectively. The observed average τwi was 87.0 ± 28.7 seconds, whereas the average τwo was 73.5 ± 21.6 seconds. CONCLUSION IR-ufSSFP allows fast, steady-state, and dynamic oxygen-dependent relaxometry of the human lung. Magn Reson Med 79:839-845, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Grzegorz Bauman
- Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.,Deparment of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Orso Pusterla
- Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.,Deparment of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Francesco Santini
- Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.,Deparment of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Oliver Bieri
- Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.,Deparment of Biomedical Engineering, University of Basel, Basel, Switzerland
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25
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Kindvall SSI, Diaz S, Svensson J, Wollmer P, Olsson LE. The change of longitudinal relaxation rate in oxygen enhanced pulmonary MRI depends on age and BMI but not diffusing capacity of carbon monoxide in healthy never-smokers. PLoS One 2017; 12:e0177670. [PMID: 28494006 PMCID: PMC5426684 DOI: 10.1371/journal.pone.0177670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 05/01/2017] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE Oxygen enhanced pulmonary MRI is a promising modality for functional lung studies and has been applied to a wide range of pulmonary conditions. The purpose of this study was to characterize the oxygen enhancement effect in the lungs of healthy, never-smokers, in light of a previously established relationship between oxygen enhancement and diffusing capacity of carbon monoxide in the lung (DL,CO) in patients with lung disease. METHODS In 30 healthy never-smoking volunteers, an inversion recovery with gradient echo read-out (Snapshot-FLASH) was used to quantify the difference in longitudinal relaxation rate, while breathing air and 100% oxygen, ΔR1, at 1.5 Tesla. Measurements were performed under multiple tidal inspiration breath-holds. RESULTS In single parameter linear models, ΔR1 exhibit a significant correlation with age (p = 0.003) and BMI (p = 0.0004), but not DL,CO (p = 0.33). Stepwise linear regression of ΔR1 yields an optimized model including an age-BMI interaction term. CONCLUSION In this healthy, never-smoking cohort, age and BMI are both predictors of the change in MRI longitudinal relaxation rate when breathing oxygen. However, DL,CO does not show a significant correlation with the oxygen enhancement. This is possibly because oxygen transfer in the lung is not diffusion limited at rest in healthy individuals. This work stresses the importance of using a physiological model to understand results from oxygen enhanced MRI.
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Affiliation(s)
| | - Sandra Diaz
- Medical Radiology, Translational Medicine, Lund University, Malmö, Sweden
| | - Jonas Svensson
- Medical Imaging and Physiology, Skane University Hospital, Lund, Sweden
| | - Per Wollmer
- Clinical Physiology, Translational Medicine, Lund University, Malmö, Sweden
| | - Lars E. Olsson
- Medical Radiation Physics, Translational Medicine, Lund University, Malmö, Sweden
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26
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Pusterla O, Bauman G, Bieri O. Three-dimensional oxygen-enhanced MRI of the human lung at 1.5T with ultra-fast balanced steady-state free precession. Magn Reson Med 2017; 79:246-255. [PMID: 28337782 DOI: 10.1002/mrm.26665] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/11/2017] [Accepted: 02/13/2017] [Indexed: 11/12/2022]
Abstract
PURPOSE To assess the feasibility of 3D oxygen-enhanced (OE) MRI of the lung at 1.5T using multi-volumetric ultra-fast balanced steady-state free precession (ufSSFP) acquisitions. METHODS Isotropic imaging of the lung for OE-MRI was performed with an adapted 3D ufSSFP sequence using five breath-hold acquisitions ranging from functional residual capacity to tidal inspiration under both normoxic (room air) and hyperoxic (100% O2 ) gas conditions. For each O2 concentration, a sponge model (which captures the parenchymal signal intensity variation as a function of the lung volume) was fitted to the acquired multi-volumetric datasets after semiautomatic lung segmentation and deformable image registration. From the retrieved model parameters, 3D oxygen-enhancement maps were calculated. RESULTS For OE ufSSFP imaging, the maximum parenchymal signal is observed for flip angles around 23° under both normoxic and hyperoxic conditions. It is found that the sponge model accurately describes parenchymal signal at different breathing positions, thereby mitigating the confounding bias in the estimated oxygen enhancement from residual density modulations. From the model, an average lung oxygen enhancement of 7.0% ± 0.3% was found in the healthy volunteers, and the oxygen-enhancement maps indicate a ventral to dorsal gravitation-related gradient. CONCLUSION The study demonstrates the feasibility of whole-lung OE-MRI from multi-volumetric ufSSFP in healthy volunteers. Magn Reson Med 79:246-255, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Orso Pusterla
- Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.,Department of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Grzegorz Bauman
- Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.,Department of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Oliver Bieri
- Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.,Department of Biomedical Engineering, University of Basel, Basel, Switzerland
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27
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Dietrich O, Gaass T, Reiser MF. T1 relaxation time constants, influence of oxygen, and the oxygen transfer function of the human lung at 1.5 T—A meta-analysis. Eur J Radiol 2017; 86:252-260. [DOI: 10.1016/j.ejrad.2016.11.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 12/13/2022]
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28
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DeBoer EM, Spielberg DR, Brody AS. Clinical potential for imaging in patients with asthma and other lung disorders. J Allergy Clin Immunol 2016; 139:21-28. [PMID: 27871877 DOI: 10.1016/j.jaci.2016.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/10/2016] [Accepted: 11/10/2016] [Indexed: 12/12/2022]
Abstract
The ability of lung imaging to phenotype patients, determine prognosis, and predict response to treatment is expanding in clinical and translational research. The purpose of this perspective is to describe current imaging modalities that might be useful clinical tools in patients with asthma and other lung disorders and to explore some of the new developments in imaging modalities of the lung. These imaging modalities include chest radiography, computed tomography, lung magnetic resonance imaging, electrical impedance tomography, bronchoscopy, and others.
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Affiliation(s)
- Emily M DeBoer
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, and Breathing Institute, Children's Hospital Colorado, Aurora, Colo.
| | - David R Spielberg
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Alan S Brody
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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29
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Baldi S, Hartley R, Brightling C, Gupta S. Asthma. IMAGING 2016. [DOI: 10.1183/2312508x.10002815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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30
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Kindvall SS, Diaz S, Svensson J, Wollmer P, Slusarczyk D, Olsson LE. Influence of age and sex on the longitudinal relaxation time, T1, of the lung in healthy never-smokers. J Magn Reson Imaging 2015; 43:1250-7. [DOI: 10.1002/jmri.25085] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 10/15/2015] [Indexed: 11/12/2022] Open
Affiliation(s)
- Simon S.I. Kindvall
- Medical Radiation Physics, Translational Medicine; Lund University; Malmö Sweden
| | - Sandra Diaz
- Medical Radiology, Translational Medicine; Lund University; Malmö Sweden
| | - Jonas Svensson
- Medical imaging and physiology; Skane University Hospital; Lund Sweden
| | - Per Wollmer
- Clinical Physiology, Translational Medicine; Lund University; Malmö Sweden
| | - Dariusz Slusarczyk
- Medical Radiology, Translational Medicine; Lund University; Malmö Sweden
| | - Lars E. Olsson
- Medical Radiation Physics, Translational Medicine; Lund University; Malmö Sweden
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31
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A method for mapping regional oxygen and CO2 transfer in the lung. Respir Physiol Neurobiol 2015; 222:29-47. [PMID: 26563454 DOI: 10.1016/j.resp.2015.10.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 10/02/2015] [Accepted: 10/25/2015] [Indexed: 11/22/2022]
Abstract
This paper presents a novel approach to visualizing regional lung function, through quantitative three-dimensional maps of O2 and CO2 transfer rates. These maps describe the contribution of anatomical regions to overall gas exchange and demonstrate how transfer rates of the two gas species' differ regionally. An algorithm for generating such maps is presented, and for illustration, regional gas transfer maps were generated using values of ventilation and perfusion imaged by PET/CT for a healthy subject and an asthmatic patient after bronchoprovocation. In a sensitivity analysis, compartment values of gas transfer showed minor sensitivity to imaging noise in the ventilation and perfusion data, and moderate sensitivity to estimation errors in global lung input values, chiefly global alveolar ventilation, followed by cardiac output and arterial-venous O2 content difference. Gas transfer maps offer an intuitive display of physiologically relevant lung function at a regional level, the potential for an improved understanding of pulmonary gas exchange in health and disease, and potentially a presurgical evaluation tool.
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32
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Tiddens HAWM, Stick SM, Wild JM, Ciet P, Parker GJM, Koch A, Vogel-Claussen J. Respiratory tract exacerbations revisited: ventilation, inflammation, perfusion, and structure (VIPS) monitoring to redefine treatment. Pediatr Pulmonol 2015; 50 Suppl 40:S57-65. [PMID: 26335955 DOI: 10.1002/ppul.23266] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 07/10/2015] [Accepted: 07/13/2015] [Indexed: 12/11/2022]
Abstract
For cystic fibrosis (CF) patients older than 6 years there are convincing data that suggest respiratory tract exacerbations (RTE) play an important role in the progressive loss of functional lung tissue. There is a poor understanding of the pathobiology of RTE and whether specific treatment of RTE reduces lung damage in the long term. In addition, there are limited tools available to measure the various components of CF lung disease and responses to therapy. Therefore, in order to better understand the impact of RTE on CF lung disease we need to develop sensitive measures to characterize RTE and responses to treatment; and improve our understanding of structure-function changes during treatment of RTE. In this paper we review our current knowledge of the impact of RTE on the progression of lung disease and identify strategies to improve our understanding of the pathobiology of RTE. By improving our knowledge regarding RTE in CF we will be better positioned to develop approaches to treatment that are individualized and that can prevent permanent structural damage. We suggest the development of a ventilation, perfusion, inflammation and structure (VIPS)-MRI suite that supplies the clinician with data on ventilation, inflammation, perfusion, and structure in one MRI session. VIPS-MRI could be an important step to better understand the factors that contribute to and limit treatment efficacy of RTE.
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Affiliation(s)
- Harm A W M Tiddens
- Department of Pediatric Pulmonology and Allergology, Erasmus Medical Centre-Sophia Children's Hospital, Rotterdam, the Netherlands.,Department of Radiology, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Stephen M Stick
- Telethon Institute for Child Health Research, The University of Western Australia, Perth, Australia.,School of Paediatrics and Child Health Research, The University of Western Australia, Perth, Australia
| | - Jim M Wild
- Department of Academic Radiology, University of Sheffield, UK
| | - Pierluigi Ciet
- Department of Pediatric Pulmonology and Allergology, Erasmus Medical Centre-Sophia Children's Hospital, Rotterdam, the Netherlands.,Department of Radiology, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Geoffrey J M Parker
- Centre for Imaging Sciences, The University of Manchester, Manchester, UK.,Biomedical Imaging Institute, The University of Manchester, Manchester, UK.,Bioxydyn Limited, Manchester, UK
| | - Armin Koch
- Department of Biometry, Hannover Medical School, Hannover, Germany
| | - Jens Vogel-Claussen
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
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33
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Hartley R, Baldi S, Brightling C, Gupta S. Novel imaging approaches in adult asthma and their clinical potential. Expert Rev Clin Immunol 2015; 11:1147-62. [PMID: 26289375 DOI: 10.1586/1744666x.2015.1072049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Currently, imaging in asthma is confined to chest radiography and CT. The emergence of new imaging techniques and tremendous improvement of existing imaging methods, primarily due to technological advancement, has completely changed its research and clinical prospects. In research, imaging in asthma is now being employed to provide quantitative assessment of morphology, function and pathogenic processes at the molecular level. The unique ability of imaging for non-invasive, repeated, quantitative, and in vivo assessment of structure and function in asthma could lead to identification of 'imaging biomarkers' with potential as outcome measures in future clinical trials. Emerging imaging techniques and their utility in the research and clinical setting is discussed in this review.
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Affiliation(s)
- Ruth Hartley
- a 1 Department of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester, LE3 9QP, UK
| | - Simonetta Baldi
- a 1 Department of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester, LE3 9QP, UK
| | - Chris Brightling
- a 1 Department of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester, LE3 9QP, UK
| | - Sumit Gupta
- a 1 Department of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester, LE3 9QP, UK.,b 2 Radiology Department, Glenfield Hospital, University Hospitals of Leicester NHS Trust, Leicester, LE3 9QP, UK
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