1
|
Tejwani V, Siddharthan T. Ventilation Heterogeneity: A Treatable Trait in Asthma. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2024; 12:936-937. [PMID: 38583928 DOI: 10.1016/j.jaip.2024.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 01/04/2024] [Indexed: 04/09/2024]
Affiliation(s)
- Vickram Tejwani
- Department of Pulmonary Medicine, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Trishul Siddharthan
- Department of Pulmonary, Critical Care and Sleep Medicine, University of Miami, Miller School of Medicine, Miami, Florida.
| |
Collapse
|
2
|
Hsia CCW, Bates JHT, Driehuys B, Fain SB, Goldin JG, Hoffman EA, Hogg JC, Levin DL, Lynch DA, Ochs M, Parraga G, Prisk GK, Smith BM, Tawhai M, Vidal Melo MF, Woods JC, Hopkins SR. Quantitative Imaging Metrics for the Assessment of Pulmonary Pathophysiology: An Official American Thoracic Society and Fleischner Society Joint Workshop Report. Ann Am Thorac Soc 2023; 20:161-195. [PMID: 36723475 PMCID: PMC9989862 DOI: 10.1513/annalsats.202211-915st] [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] [Indexed: 02/02/2023] Open
Abstract
Multiple thoracic imaging modalities have been developed to link structure to function in the diagnosis and monitoring of lung disease. Volumetric computed tomography (CT) renders three-dimensional maps of lung structures and may be combined with positron emission tomography (PET) to obtain dynamic physiological data. Magnetic resonance imaging (MRI) using ultrashort-echo time (UTE) sequences has improved signal detection from lung parenchyma; contrast agents are used to deduce airway function, ventilation-perfusion-diffusion, and mechanics. Proton MRI can measure regional ventilation-perfusion ratio. Quantitative imaging (QI)-derived endpoints have been developed to identify structure-function phenotypes, including air-blood-tissue volume partition, bronchovascular remodeling, emphysema, fibrosis, and textural patterns indicating architectural alteration. Coregistered landmarks on paired images obtained at different lung volumes are used to infer airway caliber, air trapping, gas and blood transport, compliance, and deformation. This document summarizes fundamental "good practice" stereological principles in QI study design and analysis; evaluates technical capabilities and limitations of common imaging modalities; and assesses major QI endpoints regarding underlying assumptions and limitations, ability to detect and stratify heterogeneous, overlapping pathophysiology, and monitor disease progression and therapeutic response, correlated with and complementary to, functional indices. The goal is to promote unbiased quantification and interpretation of in vivo imaging data, compare metrics obtained using different QI modalities to ensure accurate and reproducible metric derivation, and avoid misrepresentation of inferred physiological processes. The role of imaging-based computational modeling in advancing these goals is emphasized. Fundamental principles outlined herein are critical for all forms of QI irrespective of acquisition modality or disease entity.
Collapse
|
3
|
Shepelytskyi Y, Grynko V, Rao MR, Li T, Agostino M, Wild JM, Albert MS. Hyperpolarized 129 Xe imaging of the brain: Achievements and future challenges. Magn Reson Med 2022; 88:83-105. [PMID: 35253919 PMCID: PMC9314594 DOI: 10.1002/mrm.29200] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/22/2021] [Accepted: 01/25/2022] [Indexed: 11/25/2022]
Abstract
Hyperpolarized (HP) xenon-129 (129 Xe) brain MRI is a promising imaging modality currently under extensive development. HP 129 Xe is nontoxic, capable of dissolving in pulmonary blood, and is extremely sensitive to the local environment. After dissolution in the pulmonary blood, HP 129 Xe travels with the blood flow to the brain and can be used for functional imaging such as perfusion imaging, hemodynamic response detection, and blood-brain barrier permeability assessment. HP 129 Xe MRI imaging of the brain has been performed in animals, healthy human subjects, and in patients with Alzheimer's disease and stroke. In this review, the overall progress in the field of HP 129 Xe brain imaging is discussed, along with various imaging approaches and pulse sequences used to optimize HP 129 Xe brain MRI. In addition, current challenges and limitations of HP 129 Xe brain imaging are discussed, as well as possible methods for their mitigation. Finally, potential pathways for further development are also discussed. HP 129 Xe MRI of the brain has the potential to become a valuable novel perfusion imaging technique and has the potential to be used in the clinical setting in the future.
Collapse
Affiliation(s)
- Yurii Shepelytskyi
- Chemistry Department, Lakehead University, Thunder Bay, Ontario, Canada.,Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada
| | - Vira Grynko
- Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada.,Chemistry and Materials Science Program, Lakehead University, Thunder Bay, Ontario, Canada
| | - Madhwesha R Rao
- POLARIS, Unit of Academic Radiology, Department of IICD, University of Sheffield, Sheffield, UK
| | - Tao Li
- Chemistry Department, Lakehead University, Thunder Bay, Ontario, Canada
| | - Martina Agostino
- Chemistry Department, Lakehead University, Thunder Bay, Ontario, Canada
| | - Jim M Wild
- POLARIS, Unit of Academic Radiology, Department of IICD, University of Sheffield, Sheffield, UK.,Insigneo Institute for in Silico Medicine, Sheffield, UK
| | - Mitchell S Albert
- Chemistry Department, Lakehead University, Thunder Bay, Ontario, Canada.,Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada.,Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Usmani OS, Han MK, Kaminsky DA, Hogg J, Hjoberg J, Patel N, Hardin M, Keen C, Rennard S, Blé FX, Brown MN. Seven Pillars of Small Airways Disease in Asthma and COPD: Supporting Opportunities for Novel Therapies. Chest 2021; 160:114-134. [PMID: 33819471 DOI: 10.1016/j.chest.2021.03.047] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 03/05/2021] [Accepted: 03/10/2021] [Indexed: 12/29/2022] Open
Abstract
Identification of pathologic changes in early and mild obstructive lung disease has shown the importance of the small airways and their contribution to symptoms. Indeed, significant small airways dysfunction has been found prior to any overt airway obstruction being detectable by conventional spirometry techniques. However, most therapies for the treatment of obstructive lung disease target the physiological changes and associated symptoms that result from chronic lung disease, rather than directly targeting the specific underlying causes of airflow disruption or the drivers of disease progression. In addition, although spirometry is the current standard for diagnosis and monitoring of response to therapy, the most widely used measure, FEV1 , does not align with the pathologic changes in early or mild disease and may not align with symptoms or exacerbation frequency in the individual patient. Newer functional and imaging techniques allow more effective assessment of small airways dysfunction; however, significant gaps in our understanding remain. Improving our knowledge of the role of small airways dysfunction in early disease in the airways, along with the identification of novel end points to measure subclinical changes in this region (ie, those not captured as symptoms or identified through standard FEV1), may lead to the development of novel therapies that directly combat early airways disease processes with a view to slowing disease progression and reversing damage. This expert opinion paper discusses small airways disease in the context of asthma and COPD and highlights gaps in current knowledge that impede earlier identification of obstructive lung disease and the development and standardization of novel small airways-specific end points for use in clinical trials.
Collapse
Affiliation(s)
- Omar S Usmani
- National Heart and Lung Institute, Imperial College London & Royal Brompton Hospital, London, UK.
| | - MeiLan K Han
- Division of Pulmonary and Critical Care, University of Michigan, Ann Arbor, MI
| | - David A Kaminsky
- Pulmonary and Critical Care, University of Vermont Larner College of Medicine, Burlington, VT
| | - James Hogg
- James Hogg Research Centre, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada
| | | | | | | | - Christina Keen
- Research and Early Development, Respiratory, Inflammation, and Autoimmune, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Stephen Rennard
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE; Translational Science and Experimental Medicine, Respiratory, Inflammation, and Autoimmune, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - François-Xavier Blé
- Translational Science and Experimental Medicine, Respiratory, Inflammation, and Autoimmune, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Mary N Brown
- Research and Early Development, Respiratory, Inflammation, and Autoimmune, BioPharmaceuticals R&D, AstraZeneca, Boston, MA
| |
Collapse
|
6
|
Nilsen K, Thompson BR, Zajakovski N, Kean M, Harris B, Cowin G, Robinson P, Prisk GK, Thien F. Airway closure is the predominant physiological mechanism of low ventilation seen on hyperpolarized helium-3 MRI lung scans. J Appl Physiol (1985) 2020; 130:781-791. [PMID: 33332988 DOI: 10.1152/japplphysiol.00163.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hyperpolarized helium-3 MRI (3He MRI) provides detailed visualization of low- (hypo- and non-) ventilated lungs. Physiological measures of gas mixing may be assessed by multiple breath nitrogen washout (MBNW) and of airway closure by a forced oscillation technique (FOT). We hypothesize that in patients with asthma, areas of low-ventilated lung on 3He MRI are the result of airway closure. Ten control subjects, ten asthma subjects with normal spirometry (non-obstructed), and ten asthmatic subjects with reduced baseline lung function (obstructed) attended two testing sessions. On visit one, baseline plethysmography was performed followed by spirometry, MBNW, and FOT assessment pre and post methacholine challenge. On visit two, 3He MRI scans were conducted pre and post methacholine challenge. Post methacholine the volume of low-ventilated lung increased from 8.3% to 13.8% in the non-obstructed group (P = 0.012) and from 13.0% to 23.1% in the obstructed group (P = 0.001). For all subjects, the volume of low ventilation from 3He MRI correlated with a marker of airway closure in obstructive subjects, Xrs (6 Hz) and the marker of ventilation heterogeneity Scond with r2 values of 0.61 (P < 0.001) and 0.56 (P < 0.001), respectively. The change in Xrs (6 Hz) correlated well (r2 = 0.45, p < 0.001), whereas the change in Scond was largely independent of the change in low ventilation volume (r2 = 0.13, P < 0.01). The only significant predictor of low ventilation volume from the multi-variate analysis was Xrs (6 Hz). This is consistent with the concept that regions of poor or absent ventilation seen on 3He MRI are primarily the result of airway closure.NEW & NOTEWORTHY This study introduces a novel technique of generating high-resolution 3D ventilation maps from hyperpolarized helium-3 MRI. It is the first study to demonstrate that regions of poor or absent ventilation seen on 3He MRI are primarily the result of airway closure.
Collapse
Affiliation(s)
- Kris Nilsen
- The Alfred Hospital, Melbourne, Australia.,Swinburne University of Technology, Melbourne, Australia
| | - Bruce R Thompson
- Swinburne University of Technology, Melbourne, Australia.,Monash University, Melbourne, Australia
| | | | - Michael Kean
- The Royal Children's Hospital, Melbourne, Australia
| | - Benjamin Harris
- University of Sydney, Sydney, Australia.,Respiratory Medicine, Royal North Shore Hospital, Sydney, Australia
| | - Gary Cowin
- National Imaging Facility, Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
| | - Phil Robinson
- The Royal Children's Hospital, Melbourne, Australia.,University of Melbourne, Melbourne, Australia.,Murdoch Children's Research Institute, Melbourne, Australia
| | - G Kim Prisk
- University of California, San Diego, California
| | - Francis Thien
- Monash University, Melbourne, Australia.,Box Hill Hospital, Eastern Health, Melbourne, Australia
| |
Collapse
|
7
|
Whitfield CA, Latimer P, Horsley A, Wild JM, Collier GJ, Jensen OE. Spectral graph theory efficiently characterizes ventilation heterogeneity in lung airway networks. J R Soc Interface 2020. [PMCID: PMC7423446 DOI: 10.1098/rsif.2020.0253] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This paper introduces a linear operator for the purposes of quantifying the spectral properties of transport within resistive trees, such as airflow in lung airway networks. The operator, which we call the Maury matrix, acts only on the terminal nodes of the tree and is equivalent to the adjacency matrix of a complete graph summarizing the relationships between all pairs of terminal nodes. We show that the eigenmodes of the Maury operator have a direct physical interpretation as the relaxation, or resistive, modes of the network. We apply these findings to both idealized and image-based models of ventilation in lung airway trees and show that the spectral properties of the Maury matrix characterize the flow asymmetry in these networks more concisely than the Laplacian modes, and that eigenvector centrality in the Maury spectrum is closely related to the phenomenon of ventilation heterogeneity caused by airway narrowing or obstruction. This method has applications in dimensionality reduction in simulations of lung mechanics, as well as for characterization of models of the airway tree derived from medical images.
Collapse
Affiliation(s)
- Carl A. Whitfield
- Department of Mathematics, University of Manchester, Manchester, UK
- Division of Inflammation, Immunity and Respiratory Medicine, University of Manchester, Manchester, UK
| | - Peter Latimer
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
| | - Alex Horsley
- Division of Inflammation, Immunity and Respiratory Medicine, University of Manchester, Manchester, UK
| | - Jim M. Wild
- POLARIS, Imaging Sciences, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Guilhem J. Collier
- POLARIS, Imaging Sciences, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Oliver E. Jensen
- Department of Mathematics, University of Manchester, Manchester, UK
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Thien F, Thompson BR. Precision Medicine in Asthma: Integrating Imaging and Inflammatory Biomarkers. Am J Respir Crit Care Med 2019; 197:845-846. [PMID: 29351001 DOI: 10.1164/rccm.201801-0031ed] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Francis Thien
- 1 Eastern Health Clinical School Monash University Melbourne, Australia.,2 Box Hill Hospital Melbourne, Australia
| | - Bruce R Thompson
- 3 Department of Allergy, Immunology and Respiratory Medicine Monash University Melbourne, Australia and.,4 Alfred Hospital Melbourne, Australia
| |
Collapse
|
10
|
Young HM, Eddy RL, Parraga G. MRI and CT lung biomarkers: Towards an in vivo understanding of lung biomechanics. Clin Biomech (Bristol, Avon) 2019; 66:107-122. [PMID: 29037603 DOI: 10.1016/j.clinbiomech.2017.09.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 09/22/2017] [Accepted: 09/27/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND The biomechanical properties of the lung are necessarily dependent on its structure and function, both of which are complex and change over time and space. This makes in vivo evaluation of lung biomechanics and a deep understanding of lung biomarkers, very challenging. In patients and animal models of lung disease, in vivo evaluations of lung structure and function are typically made at the mouth and include spirometry, multiple-breath gas washout tests and the forced oscillation technique. These techniques, and the biomarkers they provide, incorporate the properties of the whole organ system including the parenchyma, large and small airways, mouth, diaphragm and intercostal muscles. Unfortunately, these well-established measurements mask regional differences, limiting their ability to probe the lung's gross and micro-biomechanical properties which vary widely throughout the organ and its subcompartments. Pulmonary imaging has the advantage in providing regional, non-invasive measurements of healthy and diseased lung, in vivo. Here we summarize well-established and emerging lung imaging tools and biomarkers and how they may be used to generate lung biomechanical measurements. METHODS We review well-established and emerging lung anatomical, microstructural and functional imaging biomarkers generated using synchrotron x-ray tomographic-microscopy (SRXTM), micro-x-ray computed-tomography (micro-CT), clinical CT as well as magnetic resonance imaging (MRI). FINDINGS Pulmonary imaging provides measurements of lung structure, function and biomechanics with high spatial and temporal resolution. Imaging biomarkers that reflect the biomechanical properties of the lung are now being validated to provide a deeper understanding of the lung that cannot be achieved using measurements made at the mouth.
Collapse
Affiliation(s)
- Heather M Young
- Robarts Research Institute, Western University, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Rachel L Eddy
- Robarts Research Institute, Western University, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Grace Parraga
- Robarts Research Institute, Western University, London, Canada; Department of Medical Biophysics, Western University, London, Canada; Graduate Program in Biomedical Engineering, Western University, London, Canada.
| |
Collapse
|
11
|
Pozin N, Montesantos S, Katz I, Pichelin M, Vignon-Clementel I, Grandmont C. Predicted airway obstruction distribution based on dynamical lung ventilation data: A coupled modeling-machine learning methodology. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e3108. [PMID: 29799665 DOI: 10.1002/cnm.3108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 03/16/2018] [Accepted: 05/18/2018] [Indexed: 06/08/2023]
Abstract
In asthma and chronic obstructive pulmonary disease, some airways of the tracheobronchial tree can be constricted, from moderate narrowing up to closure. Those pathological patterns of obstructions affect the lung ventilation distribution. While some imaging techniques enable visualization and quantification of constrictions in proximal generations, no noninvasive technique exists to provide the airway morphology and obstruction distribution in distal areas. In this work, we propose a method that exploits lung ventilation measures to access positions of airway obstructions (restrictions and closures) in the tree. This identification approach combines a lung ventilation model, in which a 0D tree is strongly coupled to a 3D parenchyma description, along with a machine learning approach. On the basis of synthetic data generated with typical temporal and spatial resolutions as well as reconstruction errors, we obtain very encouraging results of the obstruction distribution, with a detection rate higher than 85%.
Collapse
Affiliation(s)
- N Pozin
- INRIA Paris, 2 Rue Simone IFF, Paris, 75012, France
- Laboratoire Jacques-Louis Lions, Sorbonne Université, UPMC, Paris, 75252, France
- Medical R&D, WBL Healthcare, Air Liquide Santé International, 1 Chemin de la Porte des Loges, Les Loges-en-Josas, 78350, France
| | - S Montesantos
- Medical R&D, WBL Healthcare, Air Liquide Santé International, 1 Chemin de la Porte des Loges, Les Loges-en-Josas, 78350, France
| | - I Katz
- Medical R&D, WBL Healthcare, Air Liquide Santé International, 1 Chemin de la Porte des Loges, Les Loges-en-Josas, 78350, France
- Department of Mechanical Engineering, Lafayette College, Easton, PA, 18042, USA
| | - M Pichelin
- Medical R&D, WBL Healthcare, Air Liquide Santé International, 1 Chemin de la Porte des Loges, Les Loges-en-Josas, 78350, France
| | - I Vignon-Clementel
- INRIA Paris, 2 Rue Simone IFF, Paris, 75012, France
- Laboratoire Jacques-Louis Lions, Sorbonne Université, UPMC, Paris, 75252, France
| | - C Grandmont
- INRIA Paris, 2 Rue Simone IFF, Paris, 75012, France
- Laboratoire Jacques-Louis Lions, Sorbonne Université, UPMC, Paris, 75252, France
| |
Collapse
|
12
|
Young HM, Guo F, Eddy RL, Maksym G, Parraga G. Oscillometry and pulmonary MRI measurements of ventilation heterogeneity in obstructive lung disease: relationship to quality of life and disease control. J Appl Physiol (1985) 2018. [PMID: 29543132 DOI: 10.1152/japplphysiol.01031.2017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Ventilation heterogeneity is a hallmark finding in obstructive lung disease and may be evaluated using a variety of methods, including multiple-breath gas washout and pulmonary imaging. Such methods provide an opportunity to better understand the relationships between structural and functional abnormalities in the lungs, and their relationships with important clinical outcomes. We measured ventilation heterogeneity and respiratory impedance in 100 subjects [50 patients with asthma, 22 ex-smokers, and 28 patients with chronic obstructive pulmonary disease (COPD)] using oscillometry and hyperpolarized 3He magnetic resonance imaging (MRI) and determined their relationships with quality of life scores and disease control/exacerbations. We also coregistered MRI ventilation maps to a computational airway tree model to generate patient-specific respiratory impedance predictions for comparison with experimental measurements. In COPD and asthma patients, respectively, forced oscillation technique (FOT)-derived peripheral resistance (5-19 Hz) and MRI ventilation defect percentage (VDP) were significantly related to quality of life (FOT: COPD ρ = 0.4, P = 0.004; asthma ρ = -0.3, P = 0.04; VDP: COPD ρ = 0.6, P = 0.003; asthma ρ = -0.3, P = 0.04). Patients with poorly controlled asthma (Asthmatic Control Questionnaire >2) had significantly increased resistance (5 Hz: P = 0.01; 5-19 Hz: P = 0.006) and reactance (5 Hz: P = 0.03). FOT-derived peripheral resistance (5-19 Hz) was significantly related to VDP in patients with asthma and COPD patients (asthma: ρ = 0.5, P < 0.001; COPD: ρ = 0.5, P = 0.01), whereas total respiratory impedance was related to VDP only in patients with asthma (resistance 5 Hz: ρ = 0.3, P = 0.02; reactance 5 Hz: ρ = -0.5, P < 0.001). Model-predicted and FOT-measured reactance (5 Hz) were correlated in patients with asthma (ρ = 0.5, P = 0.001), whereas in COPD patients, model-predicted and FOT-measured resistance (5-19 Hz) were correlated (ρ = 0.5, P = 0.004). In summary, in patients with asthma and COPD patients, we observed significant, independent relationships for FOT-measured impedance and MRI ventilation heterogeneity measurements with one another and with quality of life scores. NEW & NOTEWORTHY In 100 patients, including patients with asthma and ex-smokers, 3He MRI ventilation heterogeneity and respiratory system impedance were correlated and both were independently related to quality of life scores and asthma control. These findings demonstrated the critical relationships between respiratory system impedance and ventilation heterogeneity and their role in determining quality of life and disease control. These observations underscore the dominant role that abnormalities in the lung periphery play in ventilation heterogeneity that results in patients' symptoms.
Collapse
Affiliation(s)
- Heather M Young
- Robarts Research Institute, Western University , London, Ontario , Canada.,Department of Medical Biophysics, Western University , London, Ontario , Canada
| | - Fumin Guo
- Robarts Research Institute, Western University , London, Ontario , Canada.,Graduate Program in Biomedical Engineering, Western University , London, Ontario , Canada
| | - Rachel L Eddy
- Robarts Research Institute, Western University , London, Ontario , Canada.,Department of Medical Biophysics, Western University , London, Ontario , Canada
| | - Geoffrey Maksym
- School of Biomedical Engineering, Dalhousie University , Halifax, Nova Scotia , Canada
| | - Grace Parraga
- Robarts Research Institute, Western University , London, Ontario , Canada.,Department of Medical Biophysics, Western University , London, Ontario , Canada.,Graduate Program in Biomedical Engineering, Western University , London, Ontario , Canada
| |
Collapse
|
13
|
Affiliation(s)
- Toshihiro Shirai
- Department of Respiratory Medicine, Shizuoka General Hospital, Shizuoka, Japan.
| |
Collapse
|
14
|
Tiddens HAWM, Kuo W, van Straten M, Ciet P. Paediatric lung imaging: the times they are a-changin'. Eur Respir Rev 2018; 27:27/147/170097. [PMID: 29491035 DOI: 10.1183/16000617.0097-2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 12/13/2017] [Indexed: 02/06/2023] Open
Abstract
Until recently, functional tests were the most important tools for the diagnosis and monitoring of lung diseases in the paediatric population. Chest imaging has gained considerable importance for paediatric pulmonology as a diagnostic and monitoring tool to evaluate lung structure over the past decade. Since January 2016, a large number of papers have been published on innovations in chest computed tomography (CT) and/or magnetic resonance imaging (MRI) technology, acquisition techniques, image analysis strategies and their application in different disease areas. Together, these papers underline the importance and potential of chest imaging and image analysis for today's paediatric pulmonology practice. The focus of this review is chest CT and MRI, as these are, and will be, the modalities that will be increasingly used by most practices. Special attention is given to standardisation of image acquisition, image analysis and novel applications in chest MRI. The publications discussed underline the need for the paediatric pulmonology community to implement and integrate state-of-the-art imaging and image analysis modalities into their structure-function laboratory for the benefit of their patients.
Collapse
Affiliation(s)
- Harm A W M Tiddens
- Pediatric Pulmonology and Allergology, Erasmus MC - Sophia Children's Hospital, University Medical Centre, Rotterdam, The Netherlands .,Radiology and Nuclear Medicine, Erasmus University Medical Center - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Wieying Kuo
- Pediatric Pulmonology and Allergology, Erasmus MC - Sophia Children's Hospital, University Medical Centre, Rotterdam, The Netherlands.,Radiology and Nuclear Medicine, Erasmus University Medical Center - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Marcel van Straten
- Radiology and Nuclear Medicine, Erasmus University Medical Center - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Pierluigi Ciet
- Pediatric Pulmonology and Allergology, Erasmus MC - Sophia Children's Hospital, University Medical Centre, Rotterdam, The Netherlands.,Radiology and Nuclear Medicine, Erasmus University Medical Center - Sophia Children's Hospital, Rotterdam, The Netherlands
| |
Collapse
|
15
|
Lui JK, Lutchen KR. The role of heterogeneity in asthma: a structure-to-function perspective. Clin Transl Med 2017; 6:29. [PMID: 28776171 PMCID: PMC5543015 DOI: 10.1186/s40169-017-0159-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 07/26/2017] [Indexed: 02/07/2023] Open
Abstract
A number of methods have evolved through the years in probing the dysfunction that impacts mechanics and ventilation in asthma. What has been consistently found is the notion of heterogeneity that is not only captured in the frequency dependence of lung mechanics measurements but also rendered on imaging as patchy diffuse areas of ventilation defects. The degree of heterogeneity has been linked to airway hyperresponsiveness, a hallmark feature of asthma. How these heterogeneous constriction patterns lead to functional impairment in asthma have only been recently explored using computational airway tree models. By synthesizing measurements of lung mechanics and advances in imaging, computational airway tree models serve as a powerful engine to accelerate our understanding of the physiologic changes that occur in asthma. This review will be focused on the current state of investigational work on the role of heterogeneity in asthma, specifically exploring the structural and functional relationships.
Collapse
Affiliation(s)
- Justin K. Lui
- Department of Medicine, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655 USA
| | - Kenneth R. Lutchen
- Department of Biomedical Engineering, Boston University, Boston, MA 02215 USA
| |
Collapse
|
16
|
Leary D, Svenningsen S, Guo F, Bhatawadekar S, Parraga G, Maksym GN. Hyperpolarized 3He magnetic resonance imaging ventilation defects in asthma: relationship to airway mechanics. Physiol Rep 2016; 4:4/7/e12761. [PMID: 27053294 PMCID: PMC4831329 DOI: 10.14814/phy2.12761] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 03/17/2016] [Indexed: 11/24/2022] Open
Abstract
In patients with asthma, magnetic resonance imaging (MRI) provides direct measurements of regional ventilation heterogeneity, the etiology of which is not well‐understood, nor is the relationship of ventilation abnormalities with lung mechanics. In addition, respiratory resistance and reactance are often abnormal in asthmatics and the frequency dependence of respiratory resistance is thought to reflect ventilation heterogeneity. We acquired MRI ventilation defect maps, forced expiratory volume in one‐second (FEV1), and airways resistance (Raw) measurements, and used a computational airway model to explore the relationship of ventilation defect percent (VDP) with simulated measurements of respiratory system resistance (Rrs) and reactance (Xrs). MRI ventilation defect maps were experimentally acquired in 25 asthmatics before, during, and after methacholine challenge and these were nonrigidly coregistered to the airway tree model. Using the model coregistered to ventilation defect maps, we narrowed proximal (9th) and distal (14th) generation airways that were spatially related to the MRI ventilation defects. The relationships for VDP with Raw measured using plethysmography (r = 0.79), and model predictions of Rrs>14 (r = 0.91, P < 0.0001) and Rrs>9 (r = 0.88, P < 0.0001) were significantly stronger (P = 0.005; P = 0.03, respectively) than with FEV1 (r = −0.68, P = 0.0001). The slopes for the relationship of VDP with simulated lung mechanics measurements were different (P < 0.0001); among these, the slope for the VDP‐Xrs0.2 relationship was largest, suggesting that VDP was dominated by peripheral airway heterogeneity in these patients. In conclusion, as a first step toward understanding potential links between lung mechanics and ventilation defects, impedance predictions were made using a computational airway tree model with simulated constriction of airways related to ventilation defects measured in mild‐moderate asthmatics.
Collapse
Affiliation(s)
- Del Leary
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado
| | - Sarah Svenningsen
- Robarts Research Institute, The University of Western Ontario, London, Canada Department of Medical Biophysics, The University of Western Ontario, London, Canada
| | - Fumin Guo
- Robarts Research Institute, The University of Western Ontario, London, Canada Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Canada
| | - Swati Bhatawadekar
- University Health Network-Toronto Rehabilitation Institute, Toronto, Canada
| | - Grace Parraga
- Robarts Research Institute, The University of Western Ontario, London, Canada Department of Medical Biophysics, The University of Western Ontario, London, Canada Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Canada
| | - Geoffrey N Maksym
- School of Biomedical Engineering, Dalhousie University, Halifax, Canada
| |
Collapse
|