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Peiffer JD, Altes T, Ruset IC, Hersman FW, Mugler JP, Meyer CH, Mata J, Qing K, Thomen R. Hyperpolarized 129Xe MRI, 99mTc scintigraphy, and SPECT in lung ventilation imaging: a quantitative comparison. Acad Radiol 2024; 31:1666-1675. [PMID: 37977888 PMCID: PMC11015986 DOI: 10.1016/j.acra.2023.10.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/22/2023] [Accepted: 10/22/2023] [Indexed: 11/19/2023]
Abstract
RATIONALE AND OBJECTIVES The current clinical standard for functional imaging of patients with lung ailments is nuclear medicine scintigraphy and Single Photon Emission Computed Tomography (SPECT) which detect the gamma decay of inhaled radioactive tracers. Hyperpolarized (HP) Xenon-129 MRI (XeMRI) of the lungs has recently been FDA approved and provides similar functional images of the lungs with higher spatial resolution than scintigraphy and SPECT. Here we compare Technetium-99m (99mTc) diethylene-triamine-pentaacetate scintigraphy and SPECT with HP XeMRI in healthy controls, asthma, and chronic obstructive pulmonary disorder (COPD) patients. MATERIALS AND METHODS 59 subjects, healthy, with asthma, and with COPD, underwent 99mTc scintigraphy/SPECT, standard spirometry, and HP XeMRI. XeMRI and SPECT images were registered for direct voxel-wise signal comparisons. Images were also compared using ventilation defect percentage (VDP), and a standard 6-compartment method. VDP calculated from XeMRI and SPECT images was compared to spirometry. RESULTS Median Pearson correlation coefficient for voxel-wise signal comparison was 0.698 (0.613-0.782) between scintigraphy and XeMRI and 0.398 (0.286-0.502) between SPECT and XeMRI. Correlation between VDP measures was r = 0.853, p < 0.05. VDP separated asthma and COPD from the control group and was significantly correlated with FEV1, FEV1/FVC, and FEF 25-75. CONCLUSION HP XeMRI provides equivalent information to 99mTc SPECT and standard spirometry measures. Additionally, XeMRI is non-invasive, hence it could be used for longitudinal studies for evaluating emerging treatment for lung ailments.
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Affiliation(s)
- J D Peiffer
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, Missouri 65201, USA (J.D.P., R.T.)
| | - Talissa Altes
- Department of Radiology, University of Missouri, Columbia, Missouri 65201, USA (T.A., R.T.)
| | - Iulian C Ruset
- Xemed LLC, Durham, New Hampshire 03833, USA (I.C.R., F.W.H.)
| | - F W Hersman
- Xemed LLC, Durham, New Hampshire 03833, USA (I.C.R., F.W.H.)
| | - John P Mugler
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia 22908, USA (J.P.M., C.H.M., J.M., K.Q.); Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA (J.P.M., C.H.M.)
| | - Craig H Meyer
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia 22908, USA (J.P.M., C.H.M., J.M., K.Q.); Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA (J.P.M., C.H.M.)
| | - Jamie Mata
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia 22908, USA (J.P.M., C.H.M., J.M., K.Q.)
| | - Kun Qing
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia 22908, USA (J.P.M., C.H.M., J.M., K.Q.)
| | - Robert Thomen
- Department of Chemical and Biomedical Engineering, University of Missouri, Columbia, Missouri 65201, USA (J.D.P., R.T.); Department of Radiology, University of Missouri, Columbia, Missouri 65201, USA (T.A., R.T.).
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2
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Wang Y, Spencer BA, Schmall J, Li E, Badawi RD, Jones T, Cherry SR, Wang G. High-Temporal-Resolution Lung Kinetic Modeling Using Total-Body Dynamic PET with Time-Delay and Dispersion Corrections. J Nucl Med 2023; 64:1154-1161. [PMID: 37116916 PMCID: PMC10315691 DOI: 10.2967/jnumed.122.264810] [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: 08/22/2022] [Revised: 02/22/2023] [Indexed: 04/30/2023] Open
Abstract
Tracer kinetic modeling in dynamic PET has the potential to improve the diagnosis, prognosis, and research of lung diseases. The advent of total-body PET systems with much greater detection sensitivity enables high-temporal-resolution (HTR) dynamic PET imaging of the lungs. However, existing models may become insufficient for modeling the HTR data. In this paper, we investigate the necessity of additional corrections to the input function for HTR lung kinetic modeling. Methods: Dynamic scans with HTR frames of as short as 1 s were performed on 13 healthy subjects with a bolus injection of about [Formula: see text] of 18F-FDG using the uEXPLORER total-body PET/CT system. Three kinetic models with and without time-delay and dispersion corrections were compared for the quality of lung time-activity curve fitting using the Akaike information criterion. The impact on quantification of 18F-FDG delivery rate [Formula: see text], net influx rate [Formula: see text] and fractional blood volume [Formula: see text] was assessed. Parameter identifiability analysis was also performed to evaluate the reliability of kinetic quantification with respect to noise. Correlation of kinetic parameters with age was investigated. Results: HTR dynamic imaging clearly revealed the rapid change in tracer concentration in the lungs and blood supply (i.e., the right ventricle). The uncorrected input function led to poor time-activity curve fitting and biased quantification in HTR kinetic modeling. The fitting was improved by time-delay and dispersion corrections. The proposed model resulted in an approximately 85% decrease in [Formula: see text], an approximately 75% increase in [Formula: see text], and a more reasonable [Formula: see text] (∼0.14) than the uncorrected model (∼0.04). The identifiability analysis showed that the proposed models had good quantification stability for [Formula: see text], [Formula: see text], and [Formula: see text] The [Formula: see text] estimated by the proposed model with simultaneous time-delay and dispersion corrections correlated inversely with age, as would be expected. Conclusion: Corrections to the input function are important for accurate lung kinetic analysis of HTR dynamic PET data. The modeling of both delay and dispersion can improve model fitting and significantly impact quantification of [Formula: see text], [Formula: see text], and [Formula: see text].
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Affiliation(s)
- Yiran Wang
- Department of Radiology, University of California Davis Medical Center, Sacramento, California;
- Department of Biomedical Engineering, University of California at Davis, Davis, California; and
| | - Benjamin A Spencer
- Department of Radiology, University of California Davis Medical Center, Sacramento, California
- Department of Biomedical Engineering, University of California at Davis, Davis, California; and
| | | | - Elizabeth Li
- Department of Biomedical Engineering, University of California at Davis, Davis, California; and
| | - Ramsey D Badawi
- Department of Radiology, University of California Davis Medical Center, Sacramento, California
- Department of Biomedical Engineering, University of California at Davis, Davis, California; and
| | - Terry Jones
- Department of Radiology, University of California Davis Medical Center, Sacramento, California
| | - Simon R Cherry
- Department of Radiology, University of California Davis Medical Center, Sacramento, California
- Department of Biomedical Engineering, University of California at Davis, Davis, California; and
| | - Guobao Wang
- Department of Radiology, University of California Davis Medical Center, Sacramento, California
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3
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Kizhakke Puliyakote AS, Stapleton EM, Durairaj K, Karuppusamy K, Kathiresan GB, Shanmugam K, Abdul Rahim S, Navaneethakrishnan S, Bilas M, Huang R, Metwali N, Jeronimo M, Chan KS, Guo J, Nagpal P, Peters TM, Thorne PS, Comellas AP, Hoffman EA. Imaging-based assessment of lung function in a population cooking indoors with biomass fuel: a pilot study. J Appl Physiol (1985) 2023; 134:710-721. [PMID: 36759166 PMCID: PMC10027118 DOI: 10.1152/japplphysiol.00286.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
Biomass fuels (wood) are commonly used indoors in underventilated environments for cooking in the developing world, but the impact on lung physiology is poorly understood. Quantitative computed tomography (qCT) can provide sensitive metrics to compare the lungs of women cooking with wood vs. liquified petroleum gas (LPG). We prospectively assessed (qCT and spirometry) 23 primary female cooks (18 biomass, 5 LPG) with no history of cardiopulmonary disease in Thanjavur, India. CT was obtained at coached total lung capacity (TLC) and residual volume (RV). qCT assessment included texture-derived ground glass opacity [GGO: Adaptive Multiple Feature Method (AMFM)], air-trapping (expiratory voxels ≤ -856HU) and image registration-based assessment [Disease Probability Measure (DPM)] of emphysema, functional small airways disease (%AirTrapDPM), and regional lung mechanics. In addition, within-kitchen exposure assessments included particulate matter <2.5 μm(PM2.5), black carbon, β-(1, 3)-d-glucan (surrogate for fungi), and endotoxin. Air-trapping went undetected at RV via the threshold-based measure (voxels ≤ -856HU), possibly due to density shifts in the presence of inflammation. However, DPM, utilizing image-matching, demonstrated significant air-trapping in biomass vs. LPG cooks (P = 0.049). A subset of biomass cooks (6/18), identified using k-means clustering, had markedly altered DPM-metrics: greater air-trapping (P < 0.001), lower TLC-RV volume change (P < 0.001), a lower mean anisotropic deformation index (ADI; P < 0.001), and elevated % GGO (P < 0.02). Across all subjects, a texture measure of bronchovascular bundles was correlated to the log-transformed β-(1, 3)-d-glucan concentration (P = 0.026, R = 0.46), and black carbon (P = 0.04, R = 0.44). This pilot study identified environmental links with qCT-based lung pathologies and a cluster of biomass cooks (33%) with significant small airways disease.NEW & NOTEWORTHY Quantitative computed tomography has identified a cluster of women (33%) cooking with biomass fuels (wood) with image-based markers of functional small airways disease and associated alterations in regional lung mechanics. Texture and image registration-based metrics of lung function may allow for early detection of potential inflammatory processes that may arise in response to inhaled biomass smoke, and help identify phenotypes of chronic lung disease prevalent in nonsmoking women in the developing world.
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Affiliation(s)
- Abhilash S Kizhakke Puliyakote
- Department of Radiology, University of California, San Diego, La Jolla, California, United States
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
| | - Emma M Stapleton
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Kumar Durairaj
- Department of Physics, Periyar Maniammai Institute of Science and Technology, Thanjavur, India
| | - Kesavan Karuppusamy
- Department of Physics, Periyar Maniammai Institute of Science and Technology, Thanjavur, India
| | - Geetha B Kathiresan
- Department of Electronics and Communication Engineering, Periyar Maniammai Institute of Science and Technology, Thanjavur, India
| | - Kumaran Shanmugam
- Department of Biotechnology, Periyar Maniammai Institute of Science and Technology, Thanjavur, India
| | | | | | - Monalisa Bilas
- Department of Radiology, University of Iowa, Iowa City, Iowa, United States
| | - Rui Huang
- School of Economics, Nanjing University, Nanjing, People's Republic of China
| | - Nervana Metwali
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa, United States
| | - Matthew Jeronimo
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kung-Sik Chan
- Department of Statistics and Actuarial Science, University of Iowa, Iowa City, Iowa, United States
| | - Junfeng Guo
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
- Department of Radiology, University of Iowa, Iowa City, Iowa, United States
| | - Prashant Nagpal
- Department of Radiology, University of Iowa, Iowa City, Iowa, United States
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Thomas M Peters
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa, United States
| | - Peter S Thorne
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa, United States
| | - Alejandro P Comellas
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Eric A Hoffman
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
- Department of Radiology, University of Iowa, Iowa City, Iowa, United States
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4
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Schiebler ML, Tsuchiya N, Hahn A, Fain S, Denlinger L, Jarjour N, Hoffman EA. Imaging Regional Airway Involvement of Asthma: Heterogeneity in Ventilation, Mucus Plugs and Remodeling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1426:163-184. [PMID: 37464121 DOI: 10.1007/978-3-031-32259-4_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
The imaging of asthma using chest computed tomography (CT) is well-established (Jarjour et al., Am J Respir Crit Care Med 185(4):356-62, 2012; Castro et al., J Allergy Clin Immunol 128:467-78, 2011). Moreover, recent advances in functional imaging of the lungs with advanced computer analysis of both CT and magnetic resonance images (MRI) of the lungs have begun to play a role in quantifying regional obstruction. Specifically, quantitative measurements of the airways for bronchial wall thickening, luminal narrowing and distortion, the amount of mucus plugging, parenchymal density, and ventilation defects that could contribute to the patient's disease course are instructive for the entire care team. In this chapter, we will review common imaging methods and findings that relate to the heterogeneity of asthma. This information can help to guide treatment decisions. We will discuss mucous plugging, quantitative assessment of bronchial wall thickening, delta lumen phenomenon, parenchymal low-density lung on CT, and ventilation defect percentage on MRI as metrics for assessing regional ventilatory dysfunction.
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Affiliation(s)
- Mark L Schiebler
- Cardiothoracic imaging, Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
| | - Nanae Tsuchiya
- Department of Radiology, School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Andrew Hahn
- Department of Radiology, University of Iowa, Iowa City, IA, USA
| | - Sean Fain
- Department of Radiology, Biomedical Engineering, and Human Physiology, University of Iowa, Iowa City, IA, USA
| | - Loren Denlinger
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Nizar Jarjour
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Eric A Hoffman
- Departments of Radiology, Medicine and Biomedical Engineering, University of Iowa, Iowa City, IA, USA
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5
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Tang M, Elicker BM, Henry T, Gierada DS, Schiebler ML, Huang BK, Peters MC, Castro M, Hoffman EA, Fain SB, Ash SY, Choi J, Hall C, Phillips BR, Mauger DT, Denlinger LC, Jarjour NN, Israel E, Phipatanakul W, Levy BD, Wenzel SE, Bleecker ER, Woodruff PG, Fahy JV, Dunican EM. Mucus Plugs Persist in Asthma, and Changes in Mucus Plugs Associate with Changes in Airflow over Time. Am J Respir Crit Care Med 2022; 205:1036-1045. [PMID: 35104436 PMCID: PMC9851493 DOI: 10.1164/rccm.202110-2265oc] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/31/2022] [Indexed: 02/07/2023] Open
Abstract
Rationale: Cross-sectional analysis of mucus plugs in computed tomography (CT) lung scans in the Severe Asthma Research Program (SARP)-3 showed a high mucus plug phenotype. Objectives: To determine if mucus plugs are a persistent asthma phenotype and if changes in mucus plugs over time associate with changes in lung function. Methods: In a longitudinal analysis of baseline and Year 3 CT lung scans in SARP-3 participants, radiologists generated mucus plug scores to assess mucus plug persistence over time. Changes in mucus plug score were analyzed in relation to changes in lung function and CT air trapping measures. Measurements and Main Results: In 164 participants, the mean (range) mucus plug score was similar at baseline and Year 3 (3.4 [0-20] vs. 3.8 [0-20]). Participants and bronchopulmonary segments with a baseline plug were more likely to have plugs at Year 3 than those without baseline plugs (risk ratio, 2.8; 95% confidence interval [CI], 2.0-4.1; P < 0.001; and risk ratio, 5.0; 95% CI, 4.5-5.6; P < 0.001, respectively). The change in mucus plug score from baseline to Year 3 was significantly negatively correlated with change in FEV1% predicted (rp = -0.35; P < 0.001) and with changes in CT air trapping measures (all P values < 0.05). Conclusions: Mucus plugs identify a persistent asthma phenotype, and susceptibility to mucus plugs occurs at the subject and the bronchopulmonary segment level. The association between change in mucus plug score and change in airflow over time supports a causal role for mucus plugs in mechanisms of airflow obstruction in asthma.
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Affiliation(s)
- Monica Tang
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine
| | | | - Travis Henry
- Duke Radiology, Department of Radiology, Duke University, Durham, North Carolina
| | - David S. Gierada
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Mark L. Schiebler
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Brendan K. Huang
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine
| | - Michael C. Peters
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine
| | - Mario Castro
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kansas School of Medicine, Kansas City, Kansas
| | - Eric A. Hoffman
- Department of Radiology, University of Iowa, Iowa City, Iowa
| | - Sean B. Fain
- Department of Radiology, University of Iowa, Iowa City, Iowa
| | - Samuel Y. Ash
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Jiwoong Choi
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kansas School of Medicine, Kansas City, Kansas
| | - Chase Hall
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kansas School of Medicine, Kansas City, Kansas
| | - Brenda R. Phillips
- Center for Biostatistics and Epidemiology, Pennsylvania State University School of Medicine, Harrisburg, Pennsylvania
| | - David T. Mauger
- Division of Biostatistics and Bioinformatics, Penn State College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania
| | - Loren C. Denlinger
- Division of Allergy, Pulmonary, and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Nizar N. Jarjour
- Division of Allergy, Pulmonary, and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Elliot Israel
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Wanda Phipatanakul
- Asthma, Allergy, Dermatology, Rheumatology, and Immunology, Boston Children’s Hospital, Boston, Massachusetts
| | - Bruce D. Levy
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Sally E. Wenzel
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Eugene R. Bleecker
- Department of Medicine, University of Arizona College of Medicine, Tucson, Arizona
| | - Prescott G. Woodruff
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California
| | - John V. Fahy
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California
| | - Eleanor M. Dunican
- Education and Research Centre, St. Vincent’s University Hospital, Dublin, Ireland; and
- UCD School of Medicine, University College Dublin, Dublin, Ireland
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6
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Stewart NJ, Smith LJ, Chan HF, Eaden JA, Rajaram S, Swift AJ, Weatherley ND, Biancardi A, Collier GJ, Hughes D, Klafkowski G, Johns CS, West N, Ugonna K, Bianchi SM, Lawson R, Sabroe I, Marshall H, Wild JM. Lung MRI with hyperpolarised gases: current & future clinical perspectives. Br J Radiol 2022; 95:20210207. [PMID: 34106792 PMCID: PMC9153706 DOI: 10.1259/bjr.20210207] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The use of pulmonary MRI in a clinical setting has historically been limited. Whilst CT remains the gold-standard for structural lung imaging in many clinical indications, technical developments in ultrashort and zero echo time MRI techniques are beginning to help realise non-ionising structural imaging in certain lung disorders. In this invited review, we discuss a complementary technique - hyperpolarised (HP) gas MRI with inhaled 3He and 129Xe - a method for functional and microstructural imaging of the lung that has great potential as a clinical tool for early detection and improved understanding of pathophysiology in many lung diseases. HP gas MRI now has the potential to make an impact on clinical management by enabling safe, sensitive monitoring of disease progression and response to therapy. With reference to the significant evidence base gathered over the last two decades, we review HP gas MRI studies in patients with a range of pulmonary disorders, including COPD/emphysema, asthma, cystic fibrosis, and interstitial lung disease. We provide several examples of our experience in Sheffield of using these techniques in a diagnostic clinical setting in challenging adult and paediatric lung diseases.
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Affiliation(s)
- Neil J Stewart
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Laurie J Smith
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Ho-Fung Chan
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - James A Eaden
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Smitha Rajaram
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Andrew J Swift
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Nicholas D Weatherley
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Alberto Biancardi
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Guilhem J Collier
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - David Hughes
- Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | | | - Christopher S Johns
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Noreen West
- Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Kelechi Ugonna
- Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Stephen M Bianchi
- Directorate of Respiratory Medicine, Sheffield Teaching Hospitals NHS Trust, Sheffield, UK
| | - Rod Lawson
- Directorate of Respiratory Medicine, Sheffield Teaching Hospitals NHS Trust, Sheffield, UK
| | - Ian Sabroe
- Directorate of Respiratory Medicine, Sheffield Teaching Hospitals NHS Trust, Sheffield, UK
| | - Helen Marshall
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, UK
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7
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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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8
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Sieren JC, Schroeder KE, Guo J, Asosingh K, Erzurum S, Hoffman EA. Menstrual cycle impacts lung structure measures derived from quantitative computed tomography. Eur Radiol 2021; 32:2883-2890. [PMID: 34928413 PMCID: PMC9038622 DOI: 10.1007/s00330-021-08404-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/23/2021] [Accepted: 10/11/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Quantitative computed tomography (qCT) is being increasingly incorporated in research studies and clinical trials aimed at understanding lung disease risk, progression, exacerbations, and intervention response. Menstrual cycle-based changes in lung function are recognized; however, the impact on qCT measures is currently unknown. We hypothesize that the menstrual cycle impacts qCT-derived measures of lung structure in healthy women and that the degree of measurement change may be mitigated in subjects on cyclic hormonal birth control. METHODS Thirty-one non-smoking, healthy women with regular menstrual cycles (16 of which were on cyclic hormonal birth control) underwent pulmonary function testing and qCT imaging at both menses and early luteal phase time points. Data were evaluated to identify lung measurements which changed significantly across the two key time points and to compare degree of change across metrics for the sub-cohort with versus without birth control. RESULTS The segmental airway measurements were larger and mean lung density was higher at menses compared to the early luteal phase. The sub-cohort with cyclic hormonal birth control did not have less evidence of measurement difference over the menstrual cycle compared to the sub-cohort without hormonal birth control. CONCLUSIONS This study provides evidence that qCT-derived measures from the lung are impacted by the female menstrual cycle. This indicates studies seeking to use qCT as a more sensitive measure of cross-sectional differences or longitudinal changes in these derived lung measurements should consider acquiring data at a consistent time in the menstrual cycle for pre-menopausal women and warrants further exploration. KEY POINTS • Lung measurements from chest computed tomography are used in multicenter studies exploring lung disease progression and treatment response. • The menstrual cycle impacts lung structure measurements. • Cyclic variability should be considered when evaluating longitudinal change with CT in menstruating women.
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Affiliation(s)
- Jessica C Sieren
- Department of Radiology, University of Iowa, 200 Hawkins Dr. CC704GH, Iowa City, IA, 52242, USA. .,Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA.
| | - Kimberly E Schroeder
- Department of Radiology, University of Iowa, 200 Hawkins Dr. CC704GH, Iowa City, IA, 52242, USA
| | - Junfeng Guo
- Department of Radiology, University of Iowa, 200 Hawkins Dr. CC704GH, Iowa City, IA, 52242, USA.,Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
| | - Kewal Asosingh
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.,Flow Cytometry Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Serpil Erzurum
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Eric A Hoffman
- Department of Radiology, University of Iowa, 200 Hawkins Dr. CC704GH, Iowa City, IA, 52242, USA.,Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
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9
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Mussell GT, Marshall H, Smith LJ, Biancardi AM, Hughes PJC, Capener DJ, Bray J, Swift AJ, Rajaram S, Condliffe AM, Collier GJ, Johns CS, Weatherley ND, Wild JM, Sabroe I. Xenon ventilation MRI in difficult asthma: initial experience in a clinical setting. ERJ Open Res 2021; 7:00785-2020. [PMID: 34589542 PMCID: PMC8473920 DOI: 10.1183/23120541.00785-2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 07/09/2021] [Indexed: 11/25/2022] Open
Abstract
Background Hyperpolarised gas magnetic resonance imaging (MRI) can be used to assess ventilation patterns. Previous studies have shown the image-derived metric of ventilation defect per cent (VDP) to correlate with forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and FEV1 in asthma. Objectives The aim of this study was to explore the utility of hyperpolarised xenon-129 (129Xe) ventilation MRI in clinical care and examine its relationship with spirometry and other clinical metrics in people seen in a severe asthma service. Methods 26 people referred from a severe asthma clinic for MRI scanning were assessed by contemporaneous 129Xe MRI and spirometry. A subgroup of 18 patients also underwent reversibility testing with spirometry and MRI. Quantitative MRI measures of ventilation were calculated, VDP and the ventilation heterogeneity index (VHI), and compared to spirometry, Asthma Control Questionnaire 7 (ACQ7) and blood eosinophil count. Images were reviewed by a multidisciplinary team. Results VDP and VHI correlated with FEV1, FEV1/FVC and forced expiratory flow between 25% and 75% of FVC but not with ACQ7 or blood eosinophil count. Discordance of MRI imaging and symptoms and/or pulmonary function tests also occurred, prompting diagnostic re-evaluation in some cases. Conclusion Hyperpolarised gas MRI provides a complementary method of assessment in people with difficult to manage asthma in a clinical setting. When used as a tool supporting clinical care in a severe asthma service, occurrences of discordance between symptoms, spirometry and MRI scanning indicate how MRI scanning may add to a management pathway. This article demonstrates the feasibility of using 129Xe MRI in clinical practice. Discordance between symptoms, spirometry and MRI can support the use of further treatment or suggest coexisting breathing control issues or laryngeal disorders.https://bit.ly/3ky4oXP
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Affiliation(s)
- Grace T Mussell
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Helen Marshall
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Laurie J Smith
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Alberto M Biancardi
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Paul J C Hughes
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - David J Capener
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Jody Bray
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Andrew J Swift
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Smitha Rajaram
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Alison M Condliffe
- Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK.,Respiratory Medicine, Sheffield Teaching Hospitals, NHS Foundation Trust, Sheffield, UK
| | - Guilhem J Collier
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Chris S Johns
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Nick D Weatherley
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK.,Respiratory Medicine, Sheffield Teaching Hospitals, NHS Foundation Trust, Sheffield, UK
| | - Jim M Wild
- POLARIS, Academic Radiology, Dept of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Ian Sabroe
- Respiratory Medicine, Sheffield Teaching Hospitals, NHS Foundation Trust, Sheffield, UK
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10
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Krings JG, Goss CW, Lew D, Samant M, McGregor MC, Boomer J, Bacharier LB, Sheshadri A, Hall C, Brownell J, Schechtman KB, Peterson S, McEleney S, Mauger DT, Fahy JV, Fain SB, Denlinger LC, Israel E, Washko G, Hoffman E, Wenzel SE, Castro M. Quantitative CT metrics are associated with longitudinal lung function decline and future asthma exacerbations: Results from SARP-3. J Allergy Clin Immunol 2021; 148:752-762. [PMID: 33577895 PMCID: PMC8349941 DOI: 10.1016/j.jaci.2021.01.029] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/02/2020] [Accepted: 01/08/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND Currently, there is limited knowledge regarding which imaging assessments of asthma are associated with accelerated longitudinal decline in lung function. OBJECTIVES We aimed to assess whether quantitative computed tomography (qCT) metrics are associated with longitudinal decline in lung function and morbidity in asthma. METHODS We analyzed 205 qCT scans of adult patients with asthma and calculated baseline markers of airway remodeling, lung density, and pointwise regional change in lung volume (Jacobian measures) for each participant. Using multivariable regression models, we then assessed the association of qCT measurements with the outcomes of future change in lung function, future exacerbation rate, and changes in validated measurements of morbidity. RESULTS Greater baseline wall area percent (β = -0.15 [95% CI = -0.26 to -0.05]; P < .01), hyperinflation percent (β = -0.25 [95% CI = -0.41 to -0.09]; P < .01), and Jacobian gradient measurements (cranial-caudal β = 10.64 [95% CI = 3.79-17.49]; P < .01; posterior-anterior β = -9.14, [95% CI = -15.49 to -2.78]; P < .01) were associated with more severe future lung function decline. Additionally, greater wall area percent (rate ratio = 1.06 [95% CI = 1.01-1.10]; P = .02) and air trapping percent (rate ratio =1.01 [95% CI = 1.00-1.02]; P = .03), as well as lower decline in the Jacobian determinant mean (rate ratio = 0.58 [95% CI = 0.41-0.82]; P < .01) and Jacobian determinant standard deviation (rate ratio = 0.52 [95% CI = 0.32-0.85]; P = .01), were associated with a greater rate of future exacerbations. However, imaging metrics were not associated with clinically meaningful changes in scores on validated asthma morbidity questionnaires. CONCLUSIONS Baseline qCT measures of more severe airway remodeling, more small airway disease and hyperinflation, and less pointwise regional change in lung volumes were associated with future lung function decline and asthma exacerbations.
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Affiliation(s)
- James G Krings
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, St Louis, Mo
| | - Charles W Goss
- Division of Biostatistics, Washington University in St Louis School of Medicine, St Louis, Mo
| | - Daphne Lew
- Division of Biostatistics, Washington University in St Louis School of Medicine, St Louis, Mo
| | - Maanasi Samant
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, St Louis, Mo
| | - Mary Clare McGregor
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, St Louis, Mo
| | - Jonathan Boomer
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Kansas School of Medicine, Kansas City, Kan
| | - Leonard B Bacharier
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tenn
| | - Ajay Sheshadri
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Tex
| | - Chase Hall
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Kansas School of Medicine, Kansas City, Kan
| | - Joshua Brownell
- Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, University of Wisconsin, Madison, Wis
| | - Ken B Schechtman
- Division of Biostatistics, Washington University in St Louis School of Medicine, St Louis, Mo
| | | | | | - David T Mauger
- Division of Statistics and Bioinformatics, Department of Public Health Sciences, Pennsylvania State University, Hershey, Pa
| | - John V Fahy
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, the University of California San Francisco, San Francisco, Calif
| | - Sean B Fain
- Department of Radiology and Biomedical Engineering, University of Wisconsin, Madison, Wis
| | - Loren C Denlinger
- Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, University of Wisconsin, Madison, Wis
| | - Elliot Israel
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Mass
| | - George Washko
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Mass
| | - Eric Hoffman
- Department of Radiology, Biomedical Engineering, and Medicine, University of Iowa, Iowa City, IA
| | - Sally E Wenzel
- Division of Pulmonary, Allergy, and Critical Care, Department of Medicine, the University of Pittsburgh, Pittsburgh, Pa
| | - Mario Castro
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Kansas School of Medicine, Kansas City, Kan.
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11
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Rampadarath AK, Donovan GM. Mathematical modelling of lung function — what have we learnt and where to next? CURRENT OPINION IN PHYSIOLOGY 2021. [DOI: 10.1016/j.cophys.2021.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Hyperpolarized Gas MRI Technology Breaks Through: Advancing Our Understanding of Anti-Type 2 Inflammation Therapies in Severe Asthma. Chest 2021; 158:1293-1295. [PMID: 33036069 DOI: 10.1016/j.chest.2020.07.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/10/2020] [Accepted: 07/15/2020] [Indexed: 11/21/2022] Open
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13
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Nagpal P, Guo J, Shin KM, Lim JK, Kim KB, Comellas AP, Kaczka DW, Peterson S, Lee CH, Hoffman EA. Quantitative CT imaging and advanced visualization methods: potential application in novel coronavirus disease 2019 (COVID-19) pneumonia. BJR Open 2021; 3:20200043. [PMID: 33718766 PMCID: PMC7931412 DOI: 10.1259/bjro.20200043] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/01/2020] [Accepted: 12/16/2020] [Indexed: 12/13/2022] Open
Abstract
Increasingly, quantitative lung computed tomography (qCT)-derived metrics are providing novel insights into chronic inflammatory lung diseases, including chronic obstructive pulmonary disease, asthma, interstitial lung disease, and more. Metrics related to parenchymal, airway, and vascular anatomy together with various measures associated with lung function including regional parenchymal mechanics, air trapping associated with functional small airways disease, and dual-energy derived measures of perfused blood volume are offering the ability to characterize disease phenotypes associated with the chronic inflammatory pulmonary diseases. With the emergence of COVID-19, together with its widely varying degrees of severity, its rapid progression in some cases, and the potential for lengthy post-COVID-19 morbidity, there is a new role in applying well-established qCT-based metrics. Based on the utility of qCT tools in other lung diseases, previously validated supervised classical machine learning methods, and emerging unsupervised machine learning and deep-learning approaches, we are now able to provide desperately needed insight into the acute and the chronic phases of this inflammatory lung disease. The potential areas in which qCT imaging can be beneficial include improved accuracy of diagnosis, identification of clinically distinct phenotypes, improvement of disease prognosis, stratification of care, and early objective evaluation of intervention response. There is also a potential role for qCT in evaluating an increasing population of post-COVID-19 lung parenchymal changes such as fibrosis. In this work, we discuss the basis of various lung qCT methods, using case-examples to highlight their potential application as a tool for the exploration and characterization of COVID-19, and offer scanning protocols to serve as templates for imaging the lung such that these established qCT analyses have the best chance at yielding the much needed new insights.
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Affiliation(s)
- Prashant Nagpal
- Department of Radiology, University of Iowa, Carver College of Medicine, Iowa City, IA, USA
| | | | | | - Jae-Kwang Lim
- Department of Radiology, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Ki Beom Kim
- Department of Radiology, Daegu Fatima Hospital, Daegu, South Korea
| | - Alejandro P Comellas
- Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, USA
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14
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Wilson SJ, Ward JA, Pickett HM, Baldi S, Sousa AR, Sterk PJ, Chung KF, Djukanovic R, Dahlen B, Billing B, Shaw D, Krug N, Sandstrӧm T, Brightling C, Howarth PH. Airway Elastin is increased in severe asthma and relates to proximal wall area: histological and computed tomography findings from the U-BIOPRED severe asthma study. Clin Exp Allergy 2021; 51:296-304. [PMID: 33342006 DOI: 10.1111/cea.13813] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/08/2020] [Accepted: 12/15/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND Airway remodelling, which may include goblet cell hyperplasia / hypertrophy, changes in epithelial integrity, accumulation of extracellular matrix components, smooth muscle hypertrophy and thickening of the lamina reticularis, is a feature of severe asthma and contributes to the clinical phenotype. OBJECTIVE Within the U-BIOPRED severe asthma study, we have assessed histological elements of airway remodelling and their relationship to computed tomography (CT) measures of proximal airway dimensions. METHODS Bronchial biopsies were collected from two severe asthma groups, one non-smoker (SAn, n = 28) and one current/ex-smoker (SAs/ex, n = 13), and a mild-moderate asthma group (MMA, n = 28) classified and treated according to GINA guidelines, plus a healthy control group (HC, n = 33). Movat's pentachrome technique was used to identify mucin, elastin and total collagen in these biopsies. The number of goblet cells (mucin+) was counted as a percentage of the total number of epithelial cells and the percentage mucin epithelial area measured. The percentage area of elastic fibres and total collagen within the submucosa was also measured, and the morphology of the elastic fibres classified. Participants in the asthma groups also had a CT scan to assess large airway morphometry. RESULTS The submucosal tissue elastin percentage was higher in both severe asthma groups (16.1% SAn, 18.9% SAs/ex) compared with the HC (9.7%) but did not differ between asthma groups. There was a positive relationship between elastin and airway wall area measured by CT (n = 18-20, rho=0.544, p = 0.024), which also related to an increase in elastic fibres with a thickened lamellar morphological appearance. Mucin epithelial area and total collagen were not different between the four groups. Due to small numbers of suitable CT scans, it was not feasible to compare airway morphometry between the asthma groups. CONCLUSION These findings identify a link between extent of elastin deposition and airway wall thickening in severe asthma.
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Affiliation(s)
- Susan J Wilson
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - Jonathan A Ward
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - Helen M Pickett
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - Simonetta Baldi
- Department of Respiratory Science, University of Leicester, Leicester, UK
| | - Ana R Sousa
- Respiratory Therapy Unit, GlaxoSmithKline, Stevenage, UK
| | - Peter J Sterk
- Department of Respiratory Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Kian Fan Chung
- National Heart & Lung Institute, Imperial College London, London, UK
| | | | - Barbro Dahlen
- Department of Respiratory Medicine and Allergy, The Centre for Allergy Research, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Bo Billing
- Department of Respiratory Medicine and Allergy, The Centre for Allergy Research, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Dominick Shaw
- Nottingham Respiratory Research, University of Nottingham, Nottingham, UK
| | - Norbert Krug
- Fraunhofer Institute of Toxicology & Experimental Medicine, Hannover, Germany
| | - Thomas Sandstrӧm
- Department of Respiratory Medicine, Umea University, Stockholm, Sweden
| | | | - Peter H Howarth
- Faculty of Medicine, University of Southampton, Southampton, UK
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15
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Gulhane A, Chen DL. Imaging in Asthma. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00081-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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16
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Nadeem SA, Hoffman EA, Sieren JC, Comellas AP, Bhatt SP, Barjaktarevic IZ, Abtin F, Saha PK. A CT-Based Automated Algorithm for Airway Segmentation Using Freeze-and-Grow Propagation and Deep Learning. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:405-418. [PMID: 33021934 PMCID: PMC7772272 DOI: 10.1109/tmi.2020.3029013] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) is a common lung disease, and quantitative CT-based bronchial phenotypes are of increasing interest as a means of exploring COPD sub-phenotypes, establishing disease progression, and evaluating intervention outcomes. Reliable, fully automated, and accurate segmentation of pulmonary airway trees is critical to such exploration. We present a novel approach of multi-parametric freeze-and-grow (FG) propagation which starts with a conservative segmentation parameter and captures finer details through iterative parameter relaxation. First, a CT intensity-based FG algorithm is developed and applied for airway tree segmentation. A more efficient version is produced using deep learning methods generating airway lumen likelihood maps from CT images, which are input to the FG algorithm. Both CT intensity- and deep learning-based algorithms are fully automated, and their performance, in terms of repeat scan reproducibility, accuracy, and leakages, is evaluated and compared with results from several state-of-the-art methods including an industry-standard one, where segmentation results were manually reviewed and corrected. Both new algorithms show a reproducibility of 95% or higher for total lung capacity (TLC) repeat CT scans. Experiments on TLC CT scans from different imaging sites at standard and low radiation dosages show that both new algorithms outperform the other methods in terms of leakages and branch-level accuracy. Considering the performance and execution times, the deep learning-based FG algorithm is a fully automated option for large multi-site studies.
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17
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Krings JG, Wenzel SE, Castro M. The emerging role of quantitative imaging in asthma. Br J Radiol 2020; 95:20201133. [PMID: 33242252 DOI: 10.1259/bjr.20201133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Quantitative imaging of the lung has proved to be a valuable tool that has improved our understanding of asthma. CT, MRI, and positron emission tomography have all been utilized in asthma with each modality having its own distinct advantages and disadvantages. Research has now demonstrated that quantitative imaging plays a valuable role in characterizing asthma phenotypes and endotypes, as well as potentially predicting future asthma morbidity. Nonetheless, future research is needed in order to minimize radiation exposure, standardize reporting, and further delineate how imaging can predict longitudinal outcomes. With future work, quantitative imaging may make its way into the clinical care of asthma and change our practice.
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Affiliation(s)
- James G Krings
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University in Saint Louis School of Medicine, Saint Louis, MO, USA
| | - Sally E Wenzel
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mario Castro
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of Kansas School of Medicine, Kansas City, KS, USA
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18
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Nagpal P, Narayanasamy S, Vidholia A, Guo J, Shin KM, Lee CH, Hoffman EA. Imaging of COVID-19 pneumonia: Patterns, pathogenesis, and advances. Br J Radiol 2020; 93:20200538. [PMID: 32758014 PMCID: PMC7465853 DOI: 10.1259/bjr.20200538] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/07/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022] Open
Abstract
COVID-19 pneumonia is a newly recognized lung infection. Initially, CT imaging was demonstrated to be one of the most sensitive tests for the detection of infection. Currently, with broader availability of polymerase chain reaction for disease diagnosis, CT is mainly used for the identification of complications and other defined clinical indications in hospitalized patients. Nonetheless, radiologists are interpreting lung imaging in unsuspected patients as well as in suspected patients with imaging obtained to rule out other relevant clinical indications. The knowledge of pathological findings is also crucial for imagers to better interpret various imaging findings. Identification of the imaging findings that are commonly seen with the disease is important to diagnose and suggest confirmatory testing in unsuspected cases. Proper precautionary measures will be important in such unsuspected patients to prevent further spread. In addition to understanding the imaging findings for the diagnosis of the disease, it is important to understand the growing set of tools provided by artificial intelligence. The goal of this review is to highlight common imaging findings using illustrative examples, describe the evolution of disease over time, discuss differences in imaging appearance of adult and pediatric patients and review the available literature on quantitative CT for COVID-19. We briefly address the known pathological findings of the COVID-19 lung disease that may help better understand the imaging appearance, and we provide a demonstration of novel display methodologies and artificial intelligence applications serving to support clinical observations.
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Affiliation(s)
- Prashant Nagpal
- Department of Radiology, University of Iowa, Carver College of Medicine, Iowa City, Iowa, USA
| | - Sabarish Narayanasamy
- Department of Radiology, University of Iowa, Carver College of Medicine, Iowa City, Iowa, USA
| | - Aditi Vidholia
- Department of Pathology, University of Iowa, Carver College of Medicine, Iowa City, Iowa, USA
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19
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Abstract
This article will discuss in detail the pathophysiology of asthma from the point of view of lung mechanics. In particular, we will explain how asthma is more than just airflow limitation resulting from airway narrowing but in fact involves multiple consequences of airway narrowing, including ventilation heterogeneity, airway closure, and airway hyperresponsiveness. In addition, the relationship between the airway and surrounding lung parenchyma is thought to be critically important in asthma, especially as related to the response to deep inspiration. Furthermore, dynamic changes in lung mechanics over time may yield important information about asthma stability, as well as potentially provide a window into future disease control. All of these features of mechanical properties of the lung in asthma will be explained by providing evidence from multiple investigative methods, including not only traditional pulmonary function testing but also more sophisticated techniques such as forced oscillation, multiple breath nitrogen washout, and different imaging modalities. Throughout the article, we will link the lung mechanical features of asthma to clinical manifestations of asthma symptoms, severity, and control. © 2020 American Physiological Society. Compr Physiol 10:975-1007, 2020.
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Affiliation(s)
- David A Kaminsky
- University of Vermont Larner College of Medicine, Burlington, Vermont, USA
| | - David G Chapman
- University of Technology Sydney, Sydney, New South Wales, Australia
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20
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Donovan GM, Langton D, Noble PB. Phenotype- and patient-specific modelling in asthma: Bronchial thermoplasty and uncertainty quantification. J Theor Biol 2020; 501:110337. [PMID: 32511977 DOI: 10.1016/j.jtbi.2020.110337] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 11/29/2022]
Abstract
Theoretical models can help to overcome experimental limitations to better our understanding of lung physiology and disease. While such efforts often begin in broad terms by determining the effect of a disease process on a relevant biological output, more narrowly defined simulations may inform clinical practice. Two such examples are phenotype-specific and patient-specific models, the former being specific to a group of patients with common characteristics, and the latter to an individual patient, in view of likely differences (heterogeneity) between patients. However, in order for such models to be useful, they must be sufficiently accurate, given the available data about the specific characteristics of the patient. We show that, for asthma in particular, this approach is promising: phenotype-specific targeting may be an effective way of selecting patients for treatment based on their airway remodelling phenotype, and patient-specific targeting may be viable with the use of a clinically-plausible dataset. Specifically we consider asthma and its treatment by bronchial thermoplasty, in which the airway smooth muscle layer is directly targeted by thermal energy. Patient-specific and phenotype-specific models in this context are considered using a combination of biobank data from ex vivo tissue samples, CT imaging, and optical coherence tomography which allows more detailed resolution of the airway wall structures.
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Affiliation(s)
- Graham M Donovan
- Department of Mathematics, University of Auckland, Auckland 1142, New Zealand.
| | - David Langton
- Department of Thoracic Medicine, Frankston Hospital, Peninsula Health, 2 Hastings Road, Frankston, VIC 3199, Australia; Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Vic, Australia
| | - Peter B Noble
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
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21
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Airway remodelling with spatial correlations: Implications for asthma pathogenesis. Respir Physiol Neurobiol 2020; 279:103469. [PMID: 32473215 DOI: 10.1016/j.resp.2020.103469] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/30/2020] [Accepted: 05/21/2020] [Indexed: 12/11/2022]
Abstract
Airway remodelling is a cardinal feature of asthma in which airways undergo structural changes - in particular, increased airway smooth muscle mass and total airway wall area. Remodelling has long been thought to have functional consequences in asthma due to geometric effects that can increase airway narrowing and luminal occlusion. Prior studies have examined the distribution of remodelling between and within patients, but none have yet considered the possibility for spatial correlations in airway remodelling. That is, is remodelling clustered locally, or interrelated along proximal and distal locations of the bronchial tree? In view of recent interest regarding airway remodelling produced by mechanical stimuli, we developed a mathematical model to examine whether spatial correlations in airway remodelling could arise due to cycles of bronchoconstriction and mechanotransduction. Further, we compared modelling predictions to the spatial distribution of airway remodelling in lungs from subjects with and without asthma. Results indicate that spatial correlations in airway remodelling do exist in vivo, and cycles of bronchoconstriction and mechanotransduction are one plausible mechanism for their origin. These findings offer insights into the evolution of airway remodelling in asthma, which may inform strategies for treatment and prevention.
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22
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Nadeem SA, Hoffman EA, Comellas AP, Saha PK. LOCALLY ADAPTIVE HALF-MAX METHODS FOR AIRWAY LUMEN-AREA AND WALL-THICKNESS AND THEIR REPEAT CT SCAN REPRODUCIBILITY. PROCEEDINGS. IEEE INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING 2020; 2020:10.1109/isbi45749.2020.9098558. [PMID: 34422222 PMCID: PMC8375398 DOI: 10.1109/isbi45749.2020.9098558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Quantitative computed tomography (CT)-based characterization of bronchial metrics is increasingly being used to investigate chronic obstructive pulmonary disease (COPD)-related phenotypes. Automated methods for airway measurements benefit large multi-site studies by reducing cost and subjectivity errors. Critical challenges for CT-based analysis of airway morphology are related to location of lumen and wall transitions in the presence of varying scales and intensity-contrasts from proximal to distal sites. This paper introduces locally adaptive half-max methods to locate airway lumen and wall transitions and compute cross-sectional lumen area and wall-thickness. Also, the method uses a consistency analysis of wall-thickness to avoid adjoining-structure-artifacts. Experimental results show that computed bronchial measures at individual anatomic airway tree locations are repeat CT scan reproducible with intra-class correlation coefficient (ICC) values exceeding 0.9 and 0.8 for lumen-area and wall-thickness, respectively. Observed ICC values for derived morphologic measures, e.g., lumen-area compactness (ICC>0.67) and tapering (ICC>0.47) are relatively lower.
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Affiliation(s)
- Syed Ahmed Nadeem
- Department of Electrical and Computer Engineering, College of Engineering, University of Iowa, Iowa City, IA 52242, USA
| | - Eric A Hoffman
- Department of Radiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Alejandro P Comellas
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Punam K Saha
- Department of Electrical and Computer Engineering, College of Engineering, University of Iowa, Iowa City, IA 52242, USA
- Department of Radiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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23
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Giraudo C, Evangelista L, Fraia AS, Lupi A, Quaia E, Cecchin D, Casali M. Molecular Imaging of Pulmonary Inflammation and Infection. Int J Mol Sci 2020; 21:ijms21030894. [PMID: 32019142 PMCID: PMC7037834 DOI: 10.3390/ijms21030894] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 12/14/2022] Open
Abstract
Infectious and inflammatory pulmonary diseases are a leading cause of morbidity and mortality worldwide. Although infrequently used in this setting, molecular imaging may significantly contribute to their diagnosis using techniques like single photon emission tomography (SPET), positron emission tomography (PET) with computed tomography (CT) or magnetic resonance imaging (MRI) with the support of specific or unspecific radiopharmaceutical agents. 18F-Fluorodeoxyglucose (18F-FDG), mostly applied in oncological imaging, can also detect cells actively involved in infectious and inflammatory conditions, even if with a low specificity. SPET with nonspecific (e.g., 67Gallium-citrate (67Ga citrate)) and specific tracers (e.g., white blood cells radiolabeled with 111Indium-oxine (111In) or 99mTechnetium (99mTc)) showed interesting results for many inflammatory lung diseases. However, 67Ga citrate is unfavorable by a radioprotection point of view while radiolabeled white blood cells scan implies complex laboratory settings and labeling procedures. Radiolabeled antibiotics (e.g., ciprofloxacin) have been recently tested, although they seem to be quite unspecific and cause antibiotic resistance. New radiolabeled agents like antimicrobic peptides, binding to bacterial cell membranes, seem very promising. Thus, the aim of this narrative review is to provide a comprehensive overview about techniques, including PET/MRI, and tracers that can guide the clinicians in the appropriate diagnostic pathway of infectious and inflammatory pulmonary diseases.
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Affiliation(s)
- Chiara Giraudo
- Department of Medicine-DIMED,Institute of Radiology, University of Padova, 35100 Padova, Italy; (A.S.F.); (A.L.); (E.Q.)
- Correspondence: ; Tel.: +39-049-821-2357; Fax: +39-049-821-1878
| | - Laura Evangelista
- Nuclear Medicine Unit, Department of Medicine-DIMED, University of Padova, 35128 Padova, Italy; (L.E.); (D.C.)
| | - Anna Sara Fraia
- Department of Medicine-DIMED,Institute of Radiology, University of Padova, 35100 Padova, Italy; (A.S.F.); (A.L.); (E.Q.)
| | - Amalia Lupi
- Department of Medicine-DIMED,Institute of Radiology, University of Padova, 35100 Padova, Italy; (A.S.F.); (A.L.); (E.Q.)
| | - Emilio Quaia
- Department of Medicine-DIMED,Institute of Radiology, University of Padova, 35100 Padova, Italy; (A.S.F.); (A.L.); (E.Q.)
| | - Diego Cecchin
- Nuclear Medicine Unit, Department of Medicine-DIMED, University of Padova, 35128 Padova, Italy; (L.E.); (D.C.)
- Padova Neuroscience Center (PNC), University of Padova, 35131 Padova, Italy
| | - Massimiliano Casali
- Azienda Unità Sanitaria Locale–IRCCS di Reggio Emilia, 42121 Reggio Emilia, Italy;
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24
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Donovan GM, Elliot JG, Boser SR, Green FHY, James AL, Noble PB. Patient-specific targeted bronchial thermoplasty: predictions of improved outcomes with structure-guided treatment. J Appl Physiol (1985) 2019; 126:599-606. [PMID: 30676870 DOI: 10.1152/japplphysiol.00951.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bronchial thermoplasty is a recent treatment for asthma in which ablative thermal energy is delivered to specific large airways according to clinical guidelines. Therefore, current practice is effectively "blind," as it is not informed by patient-specific data. The present study seeks to establish whether a patient-specific approach based on structural or functional patient data can improve outcomes and/or reduce the number of procedures required for clinical efficacy. We employed a combination of extensive human lung specimens and novel computational methods to predict bronchial thermoplasty outcomes guided by structural or functional data compared with current clinical practice. Response to bronchial thermoplasty was determined from changes in airway responses to strong bronchoconstrictor simulations and flow heterogeneity after one or three simulated thermoplasty procedures. Structure-guided treatment showed significant improvement over current unguided clinical practice, with a single session of structure-guided treatment producing improvements comparable with three sessions of unguided treatment. In comparison, function-guided treatment did not produce a significant improvement over current practice. Structure-guided targeting of bronchial thermoplasty is a promising avenue for improving therapy and reinforces the need for advanced imaging technologies. The functional imaging-guided approach is predicted to be less effective presently, and we make recommendations on how this approach could be improved. NEW & NOTEWORTHY Bronchial thermoplasty is a recent treatment for asthma in which thermal energy is delivered via bronchoscope to specific airways in an effort to directly target airway smooth muscle. Current practice involves the treatment of a standard set of airways, unguided by patient-specific data. We consider the potential for guided treatments, either by functional or structural data from the lung, and show that treatment guided by structural data has the potential to improve clinical practice.
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Affiliation(s)
- Graham M Donovan
- Department of Mathematics, University of Auckland , Auckland , New Zealand
| | - John G Elliot
- West Australian Sleep Disorders Research Institute, Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital , Nedlands, Western Australia , Australia
| | | | - Francis H Y Green
- Cumming School of Medicine, University of Calgary , Calgary, Alberta , Canada
| | - Alan L James
- Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, School of Medicine and Pharmacology, University of Western Australia , Australia
| | - Peter B Noble
- School of Human Sciences, University of Western Australia , Crawley, Western Australia , Australia
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25
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Abstract
Uneven distribution of ventilation, or ventilation heterogeneity, has been observed in asthma for over 60 years using multiple breath nitrogen washout (MBNW) studies. Ventilation heterogeneity has been known to predict airway hyperresponsiveness (the ability of the airways to constrict too easily and by too much) in asthma, which is a core physiological characteristic of this disease. SPECT ventilation imaging allows topographical analysis of changes in ventilation distribution. Technegas as a SPECT ventilation agent has a key advantage as it remains fixed after inhalation, which allows imaging of upright ventilation distribution, analogous of pulmonary function tests. Recent studies using Technegas ventilation SPECT have shown spatial imaging markers also relate to airway hyperresponsiveness in asthma, and are predicted by a MBNW index of peripheral ventilation heterogeneity. It has also been shown that low-ventilation regions induced by bronchoconstriction were also related to peripheral ventilation heterogeneity. Furthermore, this suggests that the function of peripheral airways may determine the topographical pattern of airway narrowing with a more widespread distribution of narrowing. SPECT ventilation adds spatial characterisation information and it should be included in research protocols to enhance the understanding of complex physiological mechanisms in asthma.
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Affiliation(s)
- Catherine Farrow
- Airway Imaging and Physiology Group, The Woolcock Institute of Medical Research, Glebe NSW 2037; Northern Clinical School, Faculty of Medicine & Health, University of SydneyNSW 2006.
| | - Gregory King
- Airway Imaging and Physiology Group, The Woolcock Institute of Medical Research, Glebe NSW 2037; Department of Respiratory Medicine, Royal North Shore Hospital, Pacific Highway, St Leonards NSW 2065
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26
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Dunican EM, Watchorn DC, Fahy JV. Autopsy and Imaging Studies of Mucus in Asthma. Lessons Learned about Disease Mechanisms and the Role of Mucus in Airflow Obstruction. Ann Am Thorac Soc 2018; 15:S184-S191. [PMID: 30431352 PMCID: PMC6322032 DOI: 10.1513/annalsats.201807-485aw] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 09/20/2018] [Indexed: 12/11/2022] Open
Abstract
Autopsy studies in fatal asthma have clearly documented the central role of airway plugging with pathologic mucus in the pathophysiology of death from asthma, but the role of mucus plugs in chronic severe asthma has been less well understood. Recently, multidetector computerized tomography imaging of the lungs has emerged as a valuable method to visualize mucus plugs in asthma. These multidetector computerized tomography data have revealed mucus plugs as a common occurrence in severe forms of asthma. In addition, an image-based mucus plug scoring system shows that mucus plugs are strongly associated with measures of airflow obstruction and with biomarkers of type 2 cytokine and eosinophilic inflammation. These data provide a rationale for treating airflow obstruction in severe asthma with mucolytics, and they also raise the possibility that treatments that target type 2 inflammation may decrease mucus plugs in asthma.
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Affiliation(s)
- Eleanor M Dunican
- 1 Department of Medicine, University College Dublin, Dublin, Ireland; and
| | - David C Watchorn
- 1 Department of Medicine, University College Dublin, Dublin, Ireland; and
| | - John V Fahy
- 2 Division of Pulmonary and Critical Care Medicine, Department of Medicine, and
- 3 Cardiovascular Research Institute, University of California San Francisco, San Francisco, California
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Farahi N, Loutsios C, Tregay N, Summers C, Lok LSC, Ruparelia P, Solanki CK, Gillett D, Chilvers ER, Peters AM. Radiolabelled leucocytes in human pulmonary disease. Br Med Bull 2018; 127:69-82. [PMID: 30052802 PMCID: PMC6312042 DOI: 10.1093/bmb/ldy022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/20/2018] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Radionuclides for leucocyte kinetic studies have progressed from non-gamma emitting cell-labelling radionuclides through gamma emitting nuclides that allow imaging of leucocyte kinetics, to the next goal of positron emission tomography (PET). SOURCES OF DATA Mostly the authors' own studies, following on from studies of the early pioneers. AREAS OF CONTROVERSY From early imaging studies, it appeared that the majority of the marginated granulocyte pool was located in the lungs. However, later work disputed this by demonstrating the exquisite sensitivity of granulocytes to ex vivo isolation and labelling, and that excessive lung activity is artefactual. AREAS OF AGREEMENT Following refinement of labelling techniques, it was shown that the majority of marginated granulocytes are located in the spleen and bone marrow. The majority of leucocytes have a pulmonary vascular transit time only a few seconds longer than erythrocytes. The minority showing slow transit, ~5% in healthy persons, is increased in systemic inflammatory disorders that cause neutrophil priming and loss of deformability. Using a range of imaging techniques, including gamma camera imaging, whole-body counting and single photon-emission computerized tomography, labelled granulocytes were subsequently used to image pulmonary trafficking in lobar pneumonia, bronchiectasis, chronic obstructive pulmonary disease and adult respiratory distress syndrome. GROWING POINTS More recently, eosinophils have been separated in pure form using magnetic bead technology for the study of eosinophil trafficking in asthma. AREAS TIMELY FOR DEVELOPING RESEARCH These include advancement of eosinophil imaging, development of monocyte labelling, development of cell labelling with PET tracers and the tracking of lymphocytes.
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Affiliation(s)
- Neda Farahi
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Chrystalla Loutsios
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Nicola Tregay
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Charlotte Summers
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Laurence S C Lok
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Prina Ruparelia
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - Chandra K Solanki
- Department of Nuclear Medicine, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK
| | - Daniel Gillett
- Department of Nuclear Medicine, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, UK
| | - Edwin R Chilvers
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, Cambridgeshire, UK
| | - A Michael Peters
- Department of Nuclear Medicine, Brighton and Sussex Medical School, Brighton, East Sussex, UK
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Racette C, Lu Z, Kowalik K, Cheng O, Bendiak G, Amin R, Dubeau A, Jensen R, Balkovec S, Gustafsson P, Ratjen F, Subbarao P. Lung clearance index is elevated in young children with symptom-controlled asthma. Health Sci Rep 2018; 1:e58. [PMID: 30623093 PMCID: PMC6266588 DOI: 10.1002/hsr2.58] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/11/2018] [Accepted: 05/18/2018] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Pulmonary function testing has been recommended as an adjunct to symptom monitoring for assessment of asthma control. Lung clearance index (LCI) measures ventilation inhomogeneity and is thought to represent changes in the small airways. It has been proposed as a useful early marker of airway disease in asthmatic subjects, and determining it is feasible in preschool children. This study aims to assess whether LCI remains elevated in symptomatically controlled asthmatic children with a history of severe asthma, compared with healthy controls. A secondary aim was to determine whether the results were consistent across the preschool and school-aged populations. METHODS Using a case-control design, we compared 33 children with currently well-controlled symptoms who had a history of severe asthma, to 45 healthy controls (age 3-15 years) matched by age, height, and sex. We performed multiple breath washout tests using sulfur hexafluoride as a tracer gas, to determine their LCI and Scond values. RESULTS In the overall study, LCI z-score values were on average 0.86 units (95% confidence interval: 0.24-1.47, P = 0.01, t-test) higher in children with a history of severe asthma with current well-controlled symptoms compared with healthy controls. In addition, within the subgroup of preschool children (age ≤ 6), the asthmatic had significantly higher LCI z-score values than their healthy controls peers (mean (SD), 0.57 (2.18) vs -1.10 (1.00), P = 0.03, t-test). Twenty-seven percent (27%; 9/33) of subjects had an LCI value greater than the upper limit of our healthy controls despite being symptom controlled. Amongst preschool children, 5 (42%; 5/12) of the asthmatic children had abnormal LCI at the individual level. CONCLUSIONS LCI is elevated in children with asthma, which may be driven by differences in the preschool population. LCI may be useful in defining preschool asthma endotypes with persistent ventilation inhomogeneity despite symptomatic control.
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Affiliation(s)
- Christine Racette
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
| | - Zihang Lu
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
- Dalla Lana School of Public HealthUniversity of TorontoTorontoOntarioCanada
| | - Krzysztof Kowalik
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
- Department of PhysiologyUniversity of TorontoTorontoOntarioCanada
| | - Olivia Cheng
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
| | - Glenda Bendiak
- Department of PediatricsUniversity of CalgaryCalgaryAlbertaCanada
| | - Reshma Amin
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
| | - Aimee Dubeau
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
| | - Renée Jensen
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
| | - Susan Balkovec
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
| | | | - Felix Ratjen
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
| | - Padmaja Subbarao
- Division of Respiratory Medicine, Department of PediatricsHospital for Sick Children and Research InstituteTorontoOntarioCanada
- Department of PhysiologyUniversity of TorontoTorontoOntarioCanada
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29
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Sieren JP, Newell JD, Barr RG, Bleecker ER, Burnette N, Carretta EE, Couper D, Goldin J, Guo J, Han MK, Hansel NN, Kanner RE, Kazerooni EA, Martinez FJ, Rennard S, Woodruff PG, Hoffman EA. SPIROMICS Protocol for Multicenter Quantitative Computed Tomography to Phenotype the Lungs. Am J Respir Crit Care Med 2018; 194:794-806. [PMID: 27482984 DOI: 10.1164/rccm.201506-1208pp] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Multidetector row computed tomography (MDCT) is increasingly taking a central role in identifying subphenotypes within chronic obstructive pulmonary disease (COPD), asthma, and other lung-related disease populations, allowing for the quantification of the amount and distribution of altered parenchyma along with the characterization of airway and vascular anatomy. The embedding of quantitative CT (QCT) into a multicenter trial with a variety of scanner makes and models along with the variety of pressures within a clinical radiology setting has proven challenging, especially in the context of a longitudinal study. SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study), sponsored by the National Institutes of Health, has established a QCT lung assessment system (QCT-LAS), which includes scanner-specific imaging protocols for lung assessment at total lung capacity and residual volume. Also included are monthly scanning of a standardized test object and web-based tools for subject registration, protocol assignment, and data transmission coupled with automated image interrogation to assure protocol adherence. The SPIROMICS QCT-LAS has been adopted and contributed to by a growing number of other multicenter studies in which imaging is embedded. The key components of the SPIROMICS QCT-LAS along with evidence of implementation success are described herein. While imaging technologies continue to evolve, the required components of a QCT-LAS provide the framework for future studies, and the QCT results emanating from SPIROMICS and the growing number of other studies using the SPIROMICS QCT-LAS will provide a shared resource of image-derived pulmonary metrics.
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Affiliation(s)
- Jered P Sieren
- 1 Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - John D Newell
- 1 Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - R Graham Barr
- 2 Department of Medicine and Department of Epidemiology, Columbia University College of Medicine, New York, New York
| | - Eugene R Bleecker
- 3 Center for Human Genomics and Personalized Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina
| | - Nathan Burnette
- 1 Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Elizabeth E Carretta
- 4 Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina
| | - David Couper
- 4 Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina
| | - Jonathan Goldin
- 5 Department of Radiology, University of California Los Angeles, Los Angeles, California
| | - Junfeng Guo
- 1 Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | | | - Nadia N Hansel
- 7 Department of Medicine, The Johns Hopkins University, Baltimore, Maryland
| | - Richard E Kanner
- 8 Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Ella A Kazerooni
- 9 Department of Radiology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Fernando J Martinez
- 10 Department of Medicine, Weill Cornell Medical College, New York, New York
| | - Stephen Rennard
- 11 Department of Internal Medicine, University of Nebraska, Omaha, Nebraska; and
| | - Prescott G Woodruff
- 12 Department of Medicine, University of California San Francisco, San Francisco, California
| | - Eric A Hoffman
- 1 Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa
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30
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Abstract
PURPOSE OF REVIEW The present review aims to summarize the most recent evidence related to imaging and severe asthma, both with regard to advances in imaging research and to their current and potential clinical implications. RECENT FINDINGS Recent work in imaging in severe asthma has principally been using computed tomography (CT) and MRI, as well as the integration of the two. Some of the most notable findings include the use of CT imaging biomarkers to create unique clusters of asthmatics, and the use of co-registration to link CT images of airways with regional variation in ventilation in MRI. In addition, temporal studies have shown that some the ventilation defects found using MRI in asthmatics are intermittent and others are persistent, but both are associated with lower lung function. SUMMARY The role of imaging in severe asthma currently is primarily in the exclusion of comorbid or other conditions, or in the assessment for complications in the setting of acute decompensation. A rapidly expanding body of literature using CT and MRI suggests that these tools may soon be of utility in the chronic management of the disease.
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Shim SS, Schiebler ML, Evans MD, Jarjour N, Sorkness RL, Denlinger LC, Rodriguez A, Wenzel S, Hoffman EA, Lin CL, Gierada DS, Castro M, Fain SB. Lumen area change (Delta Lumen) between inspiratory and expiratory multidetector computed tomography as a measure of severe outcomes in asthmatic patients. J Allergy Clin Immunol 2018; 142:1773-1780.e9. [PMID: 29438772 DOI: 10.1016/j.jaci.2017.12.1004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 12/11/2017] [Accepted: 12/18/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Quantitative computed tomographic (QCT) biomarkers of airway morphology hold potential for understanding and monitoring regional airway remodeling in asthmatic patients. OBJECTIVE We sought to determine whether the change in airway lumen area between total lung capacity (TLC) and functional residual capacity (FRC) lung volumes measured from CT imaging data was correlated with severe outcomes in asthmatic patients. METHODS We studied 152 asthmatic patients (90 female and 62 male patients) and 33 healthy subjects (12 female and 21 male subjects) using QCT. Postprocessing of airways at generations 1 to 5 (1 = trachea) was performed for wall area percentage, wall thickness percentage (WT%), lumen area at baseline total lung capacity (LATLC), lumen area at baseline functional residual capacity (LAFRC), and low attenuation area at FRC. A new metric (reflecting remodeling, distal air trapping, or both), Delta Lumen, was determined as follows: Percentage difference in lumen area (LATLC - LAFRC)/LATLC × 100. RESULTS Postprocessing of 4501 airway segments was performed (3681 segments in the 152 patients with asthma and 820 segments in the 33 healthy subjects; range, 17-28 segments per subject). Delta Lumen values were negatively correlated with WT% and low attenuation area (P < .01) in asthmatic patients. Delta Lumen values were significantly lower for airway generations 3 to 5 (segmental airways) in subjects undergoing hospitalization because of exacerbation and in patients with refractory asthma requiring treatment with systemic corticosteroids. WT% and low attenuation area were positively and Delta Lumen values were negatively associated with systemic corticosteroid treatment (P < .05), suggesting that a reduced Delta Lumen value is a potential outcome biomarker in patients with severe asthma. CONCLUSION Reduced Delta Lumen value in the central airways measured by using QCT is a promising exploratory biomarker of unstable refractory asthma that warrants further study.
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Affiliation(s)
- Sung Shine Shim
- Department of Radiology, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, Korea
| | | | - Michael D Evans
- Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, Wis
| | - Nizar Jarjour
- Department of Medicine, University of Wisconsin, Madison, Wis
| | - Ron L Sorkness
- School of Pharmacy, University of Wisconsin, Madison, Wis
| | | | - Alfonso Rodriguez
- Department of Medical Physics, University of Wisconsin, Madison, Wis
| | - Sally Wenzel
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pa
| | - Eric A Hoffman
- Departments of Radiology, Biomedical Engineering, Mechanical and Industrial Engineering, and Medicine, University of Iowa, Iowa City, Iowa
| | - Ching-Long Lin
- Departments of Radiology, Biomedical Engineering, Mechanical and Industrial Engineering, and Medicine, University of Iowa, Iowa City, Iowa
| | - David S Gierada
- Department of Radiology, Washington University, St Louis, Mo
| | - Mario Castro
- Department of Medicine, Washington University, St Louis, Mo; Department of Radiology, Washington University, St Louis, Mo
| | - Sean B Fain
- Department of Radiology, University of Wisconsin, Madison, Wis; Department of Medical Physics, University of Wisconsin, Madison, Wis; Department of Biomedical Engineering, University of Wisconsin, Madison, Wis.
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Affiliation(s)
- Elliot Israel
- From the Pulmonary and Critical Care Medicine Division-Division of Rheumatology, Immunology, and Allergy, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston (E.I.); and the Clinical Management Group and Centre for Research Excellence in Severe Asthma, Woolcock Institute of Medical Research, University of Sydney, Sydney (H.K.R.)
| | - Helen K Reddel
- From the Pulmonary and Critical Care Medicine Division-Division of Rheumatology, Immunology, and Allergy, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston (E.I.); and the Clinical Management Group and Centre for Research Excellence in Severe Asthma, Woolcock Institute of Medical Research, University of Sydney, Sydney (H.K.R.)
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Trivedi A, Hall C, Hoffman EA, Woods JC, Gierada DS, Castro M. Using imaging as a biomarker for asthma. J Allergy Clin Immunol 2017; 139:1-10. [PMID: 28065276 DOI: 10.1016/j.jaci.2016.11.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 12/31/2022]
Abstract
There have been significant advancements in the various imaging techniques being used for the evaluation of asthmatic patients, both from a clinical and research perspective. Imaging characteristics can be used to identify specific asthmatic phenotypes and provide a more detailed understanding of endotypes contributing to the pathophysiology of the disease. Computed tomography, magnetic resonance imaging, and positron emission tomography can be used to assess pulmonary structure and function. It has been shown that specific airway and lung density measurements using computed tomography correlate with clinical parameters, including severity of disease and pathology, but also provide unique phenotypes. Hyperpolarized 129Xe and 3He are gases used as contrast media for magnetic resonance imaging that provide measurement of distal lung ventilation reflecting small-airway disease. Positron emission tomography can be useful to identify and target lung inflammation in asthmatic patients. Furthermore, imaging techniques can serve as a potential biomarker and be used to assess response to therapies, including newer biological treatments and bronchial thermoplasty.
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Affiliation(s)
- Abhaya Trivedi
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St Louis, Mo
| | - Chase Hall
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St Louis, Mo
| | - Eric A Hoffman
- Department of Biomedical Engineering, Department of Radiology, University of Iowa College of Medicine, Iowa City, Iowa
| | - Jason C Woods
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - David S Gierada
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St Louis, Mo
| | - Mario Castro
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St Louis, Mo.
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34
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Barnoy EA, Kim HJ, Gjertson DW. Complexity in applying spatial analysis to describe heterogeneous air-trapping in thoracic imaging data. J Appl Stat 2017. [DOI: 10.1080/02664763.2016.1221901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Eran A. Barnoy
- Department of Biostatistics, University of California Los Angeles, Los Angeles CA, USA
- Department of Engineering, Bar Ilan University, Ramat Gan, Israel
| | - Hyun J. Kim
- Department of Biostatistics, University of California Los Angeles, Los Angeles CA, USA
| | - David W. Gjertson
- Department of Biostatistics, University of California Los Angeles, Los Angeles CA, USA
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35
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Airway Evaluation with Multidetector Computed Tomography Post-Processing Methods in Asthmatic Patients. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 934:41-7. [PMID: 27271759 DOI: 10.1007/5584_2016_23] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Asthma is a chronic inflammatory obstructive airways disease. The disease occurs regardless of age and manifests with cough, attacks of breathlessness, and tightness in the chest. The pathophysiology of asthma is complex and still not fully understood. It is essential to find answers concerning the role of each part of the bronchial tree in asthma, especially the role of small bronchioles. With the development of newer generations of multidetector computed tomography (MDCT) and advanced post-processing methods it is possible to obtain more detailed images and gain insight into further aspects of asthma. MDCT post-processing methods can be divided into two-dimensional (2D) and three-dimensional (3D). In 2D projections, visualized hypodense regions correspond to the airway flow limitations. With the more advanced methods, such as multi planar reconstructions (MPR), images in different planes (axial, coronal, or sagittal) can be created. In the MPR technique only the voxels which are adjacent to each other in the predetermined plane can be extracted from the data set. Using the minimal/maximal intensity projections and shaded surface display, the volume of interest (VOI) can be extracted. High resolution CT scans can be used to create a more advanced imaging tool - the virtual bronchoscopy (VB). Using the VB makes it possible to visualize regions of obturation in the bronchi of up to the 5-8th generation. The MDCT with advanced post-processing methods is likely to assume an important role in the differential diagnosis of asthma, particularly when the diagnosis is dubious or hard to settle due to accompanying other lung diseases.
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Rodriguez A, Ranallo FN, Judy PF, Fain SB. The effects of iterative reconstruction and kernel selection on quantitative computed tomography measures of lung density. Med Phys 2017; 44:2267-2280. [PMID: 28376262 DOI: 10.1002/mp.12255] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/23/2017] [Accepted: 02/08/2017] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To determine the effects of iterative reconstruction (IR) and high-frequency kernels on quantitative computed tomography (qCT) density measures at reduced X-ray dose. MATERIALS AND METHODS The COPDGene 2 Phantom (CTP 698, The Phantom Laboratory, Salem, NY) with four embedded lung mimicking foam densities (12lb, 20lb, and 4lb), as well as water, air, and acrylic reference inserts, was imaged using a GE 64 slice CT750 HD scanner in helical mode with four current-time products ranging from 12 to 100 mAs. The raw acquired data were reconstructed using standard (STD - low frequency) and Bone (high frequency) kernels with filtered back projection (FBP), 100% ASiR, and Veo reconstruction algorithms. The reference density inserts were manually segmented using Slicer3D (www.slicer.org), and the mean, standard deviation, and histograms of the segmented regions were generated using Fiji (http://fiji.sc/Fiji) for each reconstruction. Measurements of threshold values placed on the cumulative frequency distribution of voxels determined by these measured histograms at 5%, PD5phant , and 15%, PD15phant , (analogous to the relative area below -950 HU (RA-950) and percent density 15 (PD15) in human lung emphysema quantification, respectively), were also performed. RESULTS The use of high-resolution kernels in conjunction with ASiR and Veo did not significantly affect the mean Hounsfield units (HU) of each of the density standards (< 4 HU deviation) and current-time products within the phantom when compared with the STD+FBP reconstruction conventionally used in clinical applications. A truncation of the scanner reported HU values at -1024 that shifts the mean toward more positive values was found to cause a systematic error in lower attenuating regions. Use of IR drove convergence toward the mean of measured histograms (~100-137% increase in the number measured voxels at the mean of the histogram), while the combination of Bone+ASiR preserved the standard deviation of HU values about the mean compared to STD+FBP, with the added effect of improved spatial resolution and accuracy in airway measures. PD5phant and PD15phant were most similar between the Bone+ASiR and STD+FBP in all regions except those affected by the -1024 truncation artifact. CONCLUSIONS Extension of the scanner reportable HU values below the present limit of -1024 will mitigate discrepancies found in qCT lung densitometry in low-density regions. The density histogram became more sharply peaked, and standard deviation was reduced for IR, directly effecting density thresholds, PD5phant and PD15phant, placed on the cumulative frequency distribution of each region in the phantom, which serve as analogs to RA-950 and PD15 typically used in lung density quantitation. The combination of high-frequency kernels (Bone) with ASiR mitigates this effect and preserves density measures derived from the image histogram. Moreover, previous studies have shown improved accuracy of qCT airway measures of wall thickness (WT) and wall area percentage (WA%) when using high-frequency kernels in combination with ASiR to better represent airway walls. The results therefore suggest an IR approach for accurate assessment of airway and parenchymal density measures in the lungs.
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Affiliation(s)
- Alfonso Rodriguez
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Frank N Ranallo
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | | | - Sean B Fain
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Department of Biomedical Engineering, University of Wisconsin School of Engineering, Madison, WI, USA
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Adamson EB, Ludwig KD, Mummy DG, Fain SB. Magnetic resonance imaging with hyperpolarized agents: methods and applications. Phys Med Biol 2017; 62:R81-R123. [PMID: 28384123 DOI: 10.1088/1361-6560/aa6be8] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In the past decade, hyperpolarized (HP) contrast agents have been under active development for MRI applications to address the twin challenges of functional and quantitative imaging. Both HP helium (3He) and xenon (129Xe) gases have reached the stage where they are under study in clinical research. HP 129Xe, in particular, is poised for larger scale clinical research to investigate asthma, chronic obstructive pulmonary disease, and fibrotic lung diseases. With advances in polarizer technology and unique capabilities for imaging of 129Xe gas exchange into lung tissue and blood, HP 129Xe MRI is attracting new attention. In parallel, HP 13C and 15N MRI methods have steadily advanced in a wide range of pre-clinical research applications for imaging metabolism in various cancers and cardiac disease. The HP [1-13C] pyruvate MRI technique, in particular, has undergone phase I trials in prostate cancer and is poised for investigational new drug trials at multiple institutions in cancer and cardiac applications. This review treats the methodology behind both HP gases and HP 13C and 15N liquid state agents. Gas and liquid phase HP agents share similar technologies for achieving non-equilibrium polarization outside the field of the MRI scanner, strategies for image data acquisition, and translational challenges in moving from pre-clinical to clinical research. To cover the wide array of methods and applications, this review is organized by numerical section into (1) a brief introduction, (2) the physical and biological properties of the most common polarized agents with a brief summary of applications and methods of polarization, (3) methods for image acquisition and reconstruction specific to improving data acquisition efficiency for HP MRI, (4) the main physical properties that enable unique measures of physiology or metabolic pathways, followed by a more detailed review of the literature describing the use of HP agents to study: (5) metabolic pathways in cancer and cardiac disease and (6) lung function in both pre-clinical and clinical research studies, concluding with (7) some future directions and challenges, and (8) an overall summary.
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Affiliation(s)
- Erin B Adamson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States of America
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Choi S, Hoffman EA, Wenzel SE, Castro M, Fain S, Jarjour N, Schiebler ML, Chen K, Lin CL. Quantitative computed tomographic imaging-based clustering differentiates asthmatic subgroups with distinctive clinical phenotypes. J Allergy Clin Immunol 2017; 140:690-700.e8. [PMID: 28143694 DOI: 10.1016/j.jaci.2016.11.053] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 10/15/2016] [Accepted: 11/21/2016] [Indexed: 12/27/2022]
Abstract
BACKGROUND Imaging variables, including airway diameter, wall thickness, and air trapping, have been found to be important metrics when differentiating patients with severe asthma from those with nonsevere asthma and healthy subjects. OBJECTIVE The objective of this study was to identify imaging-based clusters and to explore the association of the clusters with existing clinical metrics. METHODS We performed an imaging-based cluster analysis using quantitative computed tomography-based structural and functional variables extracted from the respective inspiration and expiration scans of 248 asthmatic patients. The imaging-based metrics included a broader set of multiscale variables, such as inspiratory airway dimension, expiratory air trapping, and registration-based lung deformation (inspiration vs expiration). Asthma subgroups derived from a clustering method were associated with subject demographics, questionnaire results, medication history, and biomarker variables. RESULTS Cluster 1 was composed of younger patients with early-onset nonsevere asthma and reversible airflow obstruction and normal airway structure. Cluster 2 was composed of patients with a mix of patients with nonsevere and severe asthma with marginal inflammation who exhibited airway luminal narrowing without wall thickening. Clusters 3 and 4 were dominated by patients with severe asthma. Cluster 3 patients were obese female patients with reversible airflow obstruction who exhibited airway wall thickening without airway narrowing. Cluster 4 patients were late-onset older male subjects with persistent airflow obstruction who exhibited significant air trapping and reduced regional deformation. Cluster 3 and 4 patients also showed decreased lymphocyte and increased neutrophil counts, respectively. CONCLUSIONS Four image-based clusters were identified and shown to be correlated with clinical characteristics. Such clustering serves to differentiate asthma subgroups that can be used as a basis for the development of new therapies.
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Affiliation(s)
- Sanghun Choi
- Department of Mechanical and Industrial Engineering, University of Iowa, Iowa City, Iowa; IIHR-Hydroscience and Engineering, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | - Eric A Hoffman
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa; Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Internal Medicine, University of Iowa, Iowa City, Iowa
| | - Sally E Wenzel
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pa
| | - Mario Castro
- Departments of Internal Medicine and Pediatrics, Washington University School of Medicine, St Louis, Mo
| | - Sean Fain
- School of Medicine & Public Health, University of Wisconsin, Madison, Wis
| | - Nizar Jarjour
- School of Medicine & Public Health, University of Wisconsin, Madison, Wis
| | - Mark L Schiebler
- School of Medicine & Public Health, University of Wisconsin, Madison, Wis
| | - Kun Chen
- Department of Statistics, University of Connecticut, Storrs, Conn
| | - Ching-Long Lin
- Department of Mechanical and Industrial Engineering, University of Iowa, Iowa City, Iowa; IIHR-Hydroscience and Engineering, University of Iowa, Iowa City, Iowa; Department of Radiology, University of Iowa, Iowa City, Iowa.
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Tashkin DP, Kim HJ, Zeidler M, Kleerup E, Goldin J. Evaluating small-airways disease in asthmatic patients: The utility of quantitative computed tomography. J Allergy Clin Immunol 2016; 139:49-51.e2. [PMID: 27884601 DOI: 10.1016/j.jaci.2016.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 11/17/2016] [Indexed: 10/20/2022]
Affiliation(s)
- Donald P Tashkin
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, Calif.
| | - Hyun J Kim
- Department of Radiologic Sciences, David Geffen School of Medicine at UCLA, Los Angeles, Calif
| | - Michelle Zeidler
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, Calif
| | - Eric Kleerup
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, Calif
| | - Jonathan Goldin
- Department of Radiologic Sciences, David Geffen School of Medicine at UCLA, Los Angeles, Calif
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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: 1.0] [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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Soyer O, Ozen C, Cavkaytar O, Senyücel C, Dallar Y. Right middle lobe atelectasis in children with asthma and prognostic factors. Allergol Int 2016; 65:253-8. [PMID: 26806056 DOI: 10.1016/j.alit.2015.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 12/08/2015] [Accepted: 12/09/2015] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND Although right middle lobe (RML)-atelectasis of the lungs is a common complication of asthma, the relevant data is limited. The aim of this study is to define the characteristics of RML atelectasis in asthma during childhood. METHODS Children with asthma who had recently developed RML atelectasis were included; anti-inflammatory medications, clarithromycin, and inhaled salbutamol were prescribed, chest-physiotherapy (starting on the sixth day) was applied. Patients were reevaluated on the sixth, fourteenth, thirtieth, and ninetieth days, chest X-rays were taken if the atelectasis had not resolved at the time of the previous visit. RESULTS Twenty-seven patients (6.8 (4.8-8.3) years, 48.1% male) with RML atelectasis were included. Symptoms started 15 (7-30) days before admission. The thickness of the atelectasis was 11.8 ± 5.8 mm; FEV1% was 75.9 ± 14.2 and Childhood Asthma Control Test scores were 11.8 ± 5.6 at the time of admission. The atelectasis had been resolved by the sixth (n = 3), fourteenth (n = 9), thirtieth (n = 10), and ninetieth days (n = 3). The treatment response of the patients whose atelectasis resolved in fourteen days was better on the sixth-day (atelectasis thickness: 4.7 ± 1.7 vs. 11.9 ± 7.3 mm, p = 0.021) compared to those whose atelectasis resolved later. Nearly half (54.5%) of the patients whose atelectasis had resolved by fourteen days were using controller medications at the time of admission. However, only two patients (13.3%) were on controller treatment in the latter group (p = 0.032). Regression analysis didn't reveal any prognostic factors for the early resolution of atelectasis. CONCLUSIONS Early diagnosis and treatment of RML atelectasis prevents complications. Patients who had early resolution of atelectasis had already been on anti-inflammatory medications, and responded better to aggressive treatment within the first week.
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Bronchial thermoplasty and biological therapy as targeted treatments for severe uncontrolled asthma. THE LANCET RESPIRATORY MEDICINE 2016; 4:585-592. [PMID: 27230825 DOI: 10.1016/s2213-2600(16)30018-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 03/08/2016] [Accepted: 03/15/2016] [Indexed: 01/08/2023]
Abstract
Although a small proportion of patients with asthma have severe disease, it accounts for the majority of morbidity related to the illness. Severe asthma comprises a heterogeneous group of phenotypes. Targeted treatments for these phenotypes represent a major advancement in the management of severe asthma. Omalizumab, a monoclonal antibody to IgE, improves asthma control in patients with a predominant allergic phenotype. Monoclonal antibodies targeted to interleukin 4α and interleukin 5 have shown substantial benefit in patients with the eosinophilic asthma phenotype; so too have monoclonal antibodies targeted to interleukin 13 in patients with a type 2 allergic phenotype. Bronchial thermoplasty, a new technique to reduce airway smooth muscle mass, improves symptoms and reduces exacerbations in patients with severe uncontrolled asthma and the chronic airflow obstruction phenotype. While awaiting comparative trials, we can now use a targeted approach with these phenotypes, guiding our treatment selection with the best evidence. This Review will focus on the latest developments in these new treatments and inform the clinician on how to select the appropriate patient for these treatments.
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Levy BD, Noel PJ, Freemer MM, Cloutier MM, Georas SN, Jarjour NN, Ober C, Woodruff PG, Barnes KC, Bender BG, Camargo CA, Chupp GL, Denlinger LC, Fahy JV, Fitzpatrick AM, Fuhlbrigge A, Gaston BM, Hartert TV, Kolls JK, Lynch SV, Moore WC, Morgan WJ, Nadeau KC, Ownby DR, Solway J, Szefler SJ, Wenzel SE, Wright RJ, Smith RA, Erzurum SC. Future Research Directions in Asthma. An NHLBI Working Group Report. Am J Respir Crit Care Med 2016; 192:1366-72. [PMID: 26305520 DOI: 10.1164/rccm.201505-0963ws] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Asthma is a common chronic disease without cure. Our understanding of asthma onset, pathobiology, classification, and management has evolved substantially over the past decade; however, significant asthma-related morbidity and excess healthcare use and costs persist. To address this important clinical condition, the NHLBI convened a group of extramural investigators for an Asthma Research Strategic Planning workshop on September 18-19, 2014, to accelerate discoveries and their translation to patients. The workshop focused on (1) in utero and early-life origins of asthma, (2) the use of phenotypes and endotypes to classify disease, (3) defining disease modification, (4) disease management, and (5) implementation research. This report summarizes the workshop and produces recommendations to guide future research in asthma.
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Affiliation(s)
- Bruce D Levy
- 1 Brigham and Women's Hospital, Boston, Massachusetts
| | - Patricia J Noel
- 2 National Heart, Lung, and Blood Institute, Bethesda, Maryland
| | | | | | | | - Nizar N Jarjour
- 5 University of Wisconsin Hospital and Clinics, Madison, Wisconsin
| | - Carole Ober
- 6 The University of Chicago, Chicago, Illinois
| | | | | | | | | | - Geoff L Chupp
- 11 Yale University School of Medicine, New Haven, Connecticut
| | | | - John V Fahy
- 7 University of California at San Francisco, San Francisco, California
| | | | | | - Ben M Gaston
- 13 Case Western Reserve University, Cleveland, Ohio
| | - Tina V Hartert
- 14 Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jay K Kolls
- 15 University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Susan V Lynch
- 7 University of California at San Francisco, San Francisco, California
| | - Wendy C Moore
- 16 Wake Forest School of Medicine, Winston Salem, North Carolina
| | | | - Kari C Nadeau
- 18 Stanford School of Medicine, Stanford, California
| | | | | | - Stanley J Szefler
- 20 Children's Hospital Colorado and the University of Colorado School of Medicine, Denver, Colorado
| | - Sally E Wenzel
- 15 University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | - Robert A Smith
- 2 National Heart, Lung, and Blood Institute, Bethesda, Maryland
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Hoffman EA, Lynch DA, Barr RG, van Beek EJR, Parraga G. Pulmonary CT and MRI phenotypes that help explain chronic pulmonary obstruction disease pathophysiology and outcomes. J Magn Reson Imaging 2016; 43:544-57. [PMID: 26199216 PMCID: PMC5207206 DOI: 10.1002/jmri.25010] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/01/2015] [Indexed: 12/12/2022] Open
Abstract
Pulmonary x-ray computed tomographic (CT) and magnetic resonance imaging (MRI) research and development has been motivated, in part, by the quest to subphenotype common chronic lung diseases such as chronic obstructive pulmonary disease (COPD). For thoracic CT and MRI, the main COPD research tools, disease biomarkers are being validated that go beyond anatomy and structure to include pulmonary functional measurements such as regional ventilation, perfusion, and inflammation. In addition, there has also been a drive to improve spatial and contrast resolution while at the same time reducing or eliminating radiation exposure. Therefore, this review focuses on our evolving understanding of patient-relevant and clinically important COPD endpoints and how current and emerging MRI and CT tools and measurements may be exploited for their identification, quantification, and utilization. Since reviews of the imaging physics of pulmonary CT and MRI and reviews of other COPD imaging methods were previously published and well-summarized, we focus on the current clinical challenges in COPD and the potential of newly emerging MR and CT imaging measurements to address them. Here we summarize MRI and CT imaging methods and their clinical translation for generating reproducible and sensitive measurements of COPD related to pulmonary ventilation and perfusion as well as parenchyma morphology. The key clinical problems in COPD provide an important framework in which pulmonary imaging needs to rapidly move in order to address the staggering burden, costs, as well as the mortality and morbidity associated with COPD.
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Affiliation(s)
- Eric A Hoffman
- Department of Radiology, University of Iowa, Iowa City, Iowa, USA
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA
| | - David A Lynch
- Department of Radiology, National Jewish Health Center, Denver, Colorado, USA
| | - R Graham Barr
- Division of General Medicine, Division of Pulmonary, Allergy and Critical Care, Department of Medicine, Columbia University Medical Center, New York, New York, USA
- Department of Epidemiology, Columbia University Medical Center, New York, New York, USA
| | - Edwin J R van Beek
- Clinical Research Imaging Centre, Queen's Medical Research Institute, University of Edinburgh, Scotland, UK
| | - Grace Parraga
- Robarts Research Institute, University of Western Ontario, London, Canada
- Department of Medical Biophysics, University of Western Ontario, London, Canada
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Fregonese L. Regulatory perspective on the use of lung imaging in drug development. IMAGING 2016. [DOI: 10.1183/2312508x.10003515] [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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Kruger SJ, Nagle SK, Couch MJ, Ohno Y, Albert M, Fain SB. Functional imaging of the lungs with gas agents. J Magn Reson Imaging 2016; 43:295-315. [PMID: 26218920 PMCID: PMC4733870 DOI: 10.1002/jmri.25002] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 06/26/2015] [Indexed: 12/22/2022] Open
Abstract
This review focuses on the state-of-the-art of the three major classes of gas contrast agents used in magnetic resonance imaging (MRI)-hyperpolarized (HP) gas, molecular oxygen, and fluorinated gas--and their application to clinical pulmonary research. During the past several years there has been accelerated development of pulmonary MRI. This has been driven in part by concerns regarding ionizing radiation using multidetector computed tomography (CT). However, MRI also offers capabilities for fast multispectral and functional imaging using gas agents that are not technically feasible with CT. Recent improvements in gradient performance and radial acquisition methods using ultrashort echo time (UTE) have contributed to advances in these functional pulmonary MRI techniques. The relative strengths and weaknesses of the main functional imaging methods and gas agents are compared and applications to measures of ventilation, diffusion, and gas exchange are presented. Functional lung MRI methods using these gas agents are improving our understanding of a wide range of chronic lung diseases, including chronic obstructive pulmonary disease, asthma, and cystic fibrosis in both adults and children.
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Affiliation(s)
- Stanley J. Kruger
- Department of Medical Physics, University of Wisconsin – Madison, WI, U.S.A
| | - Scott K. Nagle
- Department of Medical Physics, University of Wisconsin – Madison, WI, U.S.A
- Department of Radiology, University of Wisconsin – Madison, WI, U.S.A
- Department of Pediatrics, University of Wisconsin – Madison, WI, U.S.A
| | - Marcus J. Couch
- Thunder Bay Regional Research Institute, Thunder Bay, ON, Canada
- Biotechnology Program, Lakehead University, Thunder Bay, ON, Canada
| | - Yoshiharu Ohno
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Mitchell Albert
- Thunder Bay Regional Research Institute, Thunder Bay, ON, Canada
- Department of Chemistry, Lakehead University, Thunder Bay, ON, Canada
| | - Sean B. Fain
- Department of Medical Physics, University of Wisconsin – Madison, WI, U.S.A
- Department of Radiology, University of Wisconsin – Madison, WI, U.S.A
- Department of Biomedical Engineering, University of Wisconsin – Madison, WI, U.S.A
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Altes TA, Mugler JP, Ruppert K, Tustison NJ, Gersbach J, Szentpetery S, Meyer CH, de Lange EE, Teague WG. Clinical correlates of lung ventilation defects in asthmatic children. J Allergy Clin Immunol 2015; 137:789-96.e7. [PMID: 26521043 DOI: 10.1016/j.jaci.2015.08.045] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 08/18/2015] [Accepted: 08/21/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Lung ventilation defects identified by using hyperpolarized 3-helium gas ((3)He) lung magnetic resonance imaging (MRI) are prevalent in asthmatic patients, but the clinical importance of ventilation defects is poorly understood. OBJECTIVES We sought to correlate the lung defect volume quantified by using (3)He MRI with clinical features in children with mild and severe asthma. METHODS Thirty-one children with asthma (median age, 10 years; age range, 3-17 years) underwent detailed characterization and (3)He lung MRI. Quantification of the (3)He signal defined ventilation defect and hypoventilated, ventilated, and well-ventilated volumes. RESULTS The ventilation defect to total lung volume fraction ranged from 0.1% to 11.6%. Children with ventilation defect percentages in the upper tercile were more likely to have severe asthma than children in the lower terciles (P = .005). The ventilation defect percentage correlated (P < .05 for all) positively with the inhaled corticosteroid dose, total number of controller medications, and total blood eosinophil counts and negatively with the Asthma Control Test score, FEV1 (percent predicted), FEV1/forced vital capacity ratio (percent predicted), and forced expiratory flow rate from 25% to 75% of expired volume (percent predicted). CONCLUSION The lung defect volume percentage measured by using (3)He MRI correlates with several clinical features of asthma, including severity, symptom score, medication requirement, airway physiology, and atopic markers.
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Affiliation(s)
- Talissa A Altes
- Department of Radiology, University of Missouri School of Medicine, Columbia, Mo
| | - John P Mugler
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va; Department of Biomedical Engineering, University of Virginia, Charlottesville, Va
| | - Kai Ruppert
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Nicholas J Tustison
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va
| | - Joanne Gersbach
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va
| | - Sylvia Szentpetery
- Child Health Research Center, Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Va
| | - Craig H Meyer
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va; Department of Biomedical Engineering, University of Virginia, Charlottesville, Va
| | - Eduard E de Lange
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va
| | - W Gerald Teague
- Child Health Research Center, Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Va.
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Larsson E, Tromba G, Uvdal K, Accardo A, Monego SD, Biffi S, Garrovo C, Lorenzon A, Dullin C. Quantification of structural alterations in lung disease—a proposed analysis methodology of CT scans of preclinical mouse models and patients. Biomed Phys Eng Express 2015. [DOI: 10.1088/2057-1976/1/3/035201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Sumino K, Sheshadri A, Castro M. Calcium channel blocker reduces airway remodeling-or does it? Am J Respir Crit Care Med 2015; 191:863-4. [PMID: 25876196 DOI: 10.1164/rccm.201502-0322ed] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Kaharu Sumino
- 1 Division of Pulmonary and Critical Care Medicine Washington University School of Medicine Saint Louis, Missouri and
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Wu D, Miyawaki S, Tawhai MH, Hoffman EA, Lin CL. A Numerical Study of Water Loss Rate Distributions in MDCT-Based Human Airway Models. Ann Biomed Eng 2015; 43:2708-21. [PMID: 25869455 DOI: 10.1007/s10439-015-1318-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 04/03/2015] [Indexed: 01/06/2023]
Abstract
Both three-dimensional (3D) and one-dimensional (1D) computational fluid dynamics methods are applied to study regional water loss in three multi-detector row computed-tomography-based human airway models at the minute ventilations of 6, 15 and 30 L/min. The overall water losses predicted by both 3D and 1D models in the entire respiratory tract agree with available experimental measurements. However, 3D and 1D models reveal different regional water loss rate distributions due to the 3D secondary flows formed at bifurcations. The secondary flows cause local skewed temperature and humidity distributions on inspiration acting to elevate the local water loss rate; and the secondary flow at the carina tends to distribute more cold air to the lower lobes. As a result, the 3D model predicts that the water loss rate first increases with increasing airway generation, and then decreases as the air approaches saturation, while the 1D model predicts a monotonic decrease of water loss rate with increasing airway generation. Moreover, the 3D (or 1D) model predicts relatively higher water loss rates in lower (or upper) lobes. The regional water loss rate can be related to the non-dimensional wall shear stress (τ (*)) by the non-dimensional mass transfer coefficient (h 0 (*) ) as [Formula: see text].
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Affiliation(s)
- Dan Wu
- Department of Mechanical and Industrial Engineering, 2406 Seamans Center for the Engineering Arts and Sciences, The University of Iowa, Iowa City, 52242, Iowa, USA.,Department of IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, 52242, Iowa, USA
| | - Shinjiro Miyawaki
- Department of IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, 52242, Iowa, USA
| | - Merryn H Tawhai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Eric A Hoffman
- Department of Biomedical Engineering, The University of Iowa, Iowa City, 52242, Iowa, USA.,Department of Internal Medicine, The University of Iowa, Iowa City, 52242, Iowa, USA.,Department of Radiology, The University of Iowa, Iowa City, 52242, Iowa, USA
| | - Ching-Long Lin
- Department of Mechanical and Industrial Engineering, 2406 Seamans Center for the Engineering Arts and Sciences, The University of Iowa, Iowa City, 52242, Iowa, USA. .,Department of IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, 52242, Iowa, USA.
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