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Tajima Y, Seow CY, Dong SJ, Tsutsui M, Cheung CY, Welch I, Mowbray L, Imlach B, Hildebrandt R, Apperloo K, Ryomoto B, Goodacre E, Myrdal C, Machan L, Wolff K, Elizur E, Vasilescu DM, Sin DD. Development of a unilateral porcine emphysema model induced by porcine pancreatic elastase. J Appl Physiol (1985) 2023; 135:1001-1011. [PMID: 37767558 DOI: 10.1152/japplphysiol.00801.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 09/05/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Emphysema is one of the pathological hallmarks of chronic obstructive pulmonary disease. We have recently reported that radiofrequency therapy improves lung function in rodent models of emphysema. However, preclinical data using large animals is necessary for clinical translation. Here, we describe the work performed to establish a unilateral porcine emphysema model. Different doses of porcine pancreatic elastase (PPE) were instilled into the left lung of 10 Yucatan pigs. Three additional pigs were used as controls. Six weeks after instillation, lungs were harvested. Lung compliance was measured by a water displacement method and plethysmography. Systematic uniform random sampling of the left and right lungs was performed independently to measure alveolar surface area using micro-computed tomography (micro-CT) and histology. In pigs instilled with 725-750 U/kg of PPE (PPE group, n = 6), the compliance of the left lung was significantly higher by 37.6% than that of the right lung (P = 0.03) using the water displacement method. With plethysmography, the volume of the left lung was significantly larger than that of the right lung at 3, 5, and 10 cmH2O. Measurements from either micro-CT or histology images showed a significant decrease in alveolar surface area by 14.2% or 14.5% (P = 0.031) in the left lung compared with the right lung of the PPE group. A unilateral model for mild emphysema in Yucatan pigs has been established, which can now be used for evaluating novel therapeutics and interventional strategies.NEW & NOTEWORTHY For clinical translation, preclinical data using large animal models is necessary. However, papers describing an emphysema model in pigs, which are anatomically and physiologically similar to humans, are lacking. Here, we report success in creating a unilateral mild-emphysema model in pigs with only one single dose of porcine pancreatic elastase. This model will be useful in bringing novel technologies and therapies from small animals to humans with emphysema.
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Affiliation(s)
- Yuki Tajima
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Chun Y Seow
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shou-Jin Dong
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- Respiratory Department, Chengdu First People's Hospital, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Mai Tsutsui
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Chung Y Cheung
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ian Welch
- Centre for Comparative Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Laura Mowbray
- Centre for Comparative Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Brittany Imlach
- Centre for Comparative Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rhonda Hildebrandt
- Centre for Comparative Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kayla Apperloo
- Centre for Comparative Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian Ryomoto
- Centre for Comparative Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Evan Goodacre
- Ikomed Technologies Inc, Vancouver, British Columbia, Canada
| | - Corey Myrdal
- Ikomed Technologies Inc, Vancouver, British Columbia, Canada
| | - Lindsay Machan
- Ikomed Technologies Inc, Vancouver, British Columbia, Canada
| | - Kim Wolff
- Ikomed Technologies Inc, Vancouver, British Columbia, Canada
| | - Eran Elizur
- Ikomed Technologies Inc, Vancouver, British Columbia, Canada
| | - Dragoș M Vasilescu
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Don D Sin
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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2
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Banerji R, Grifno GN, Shi L, Smolen D, LeBourdais R, Muhvich J, Eberman C, Hiller BE, Lee J, Regan K, Zheng S, Zhang S, Jiang J, Raslan AA, Breda JC, Pihl R, Traber K, Mazzilli S, Ligresti G, Mizgerd JP, Suki B, Nia HT. Crystal ribcage: a platform for probing real-time lung function at cellular resolution. Nat Methods 2023; 20:1790-1801. [PMID: 37710017 PMCID: PMC10860663 DOI: 10.1038/s41592-023-02004-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 08/10/2023] [Indexed: 09/16/2023]
Abstract
Understanding the dynamic pathogenesis and treatment response in pulmonary diseases requires probing the lung at cellular resolution in real time. Despite advances in intravital imaging, optical imaging of the lung during active respiration and circulation has remained challenging. Here, we introduce the crystal ribcage: a transparent ribcage that allows multiscale optical imaging of the functioning lung from whole-organ to single-cell level. It enables the modulation of lung biophysics and immunity through intravascular, intrapulmonary, intraparenchymal and optogenetic interventions, and it preserves the three-dimensional architecture, air-liquid interface, cellular diversity and respiratory-circulatory functions of the lung. Utilizing these capabilities on murine models of pulmonary pathologies we probed remodeling of respiratory-circulatory functions at the single-alveolus and capillary levels during disease progression. The crystal ribcage and its broad applications presented here will facilitate further studies of nearly any pulmonary disease as well as lead to the identification of new targets for treatment strategies.
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Affiliation(s)
- Rohin Banerji
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Gabrielle N Grifno
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Linzheng Shi
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Dylan Smolen
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Rob LeBourdais
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Johnathan Muhvich
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Cate Eberman
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Bradley E Hiller
- Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Jisu Lee
- Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Kathryn Regan
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Siyi Zheng
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sue Zhang
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - John Jiang
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Ahmed A Raslan
- Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
- Department of Zoology, Faculty of Science, Assiut University, Assiut, Egypt
| | - Julia C Breda
- Section of Computational Biomedicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Riley Pihl
- Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Katrina Traber
- Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Sarah Mazzilli
- Section of Computational Biomedicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Giovanni Ligresti
- Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Joseph P Mizgerd
- Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Béla Suki
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Hadi T Nia
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.
- Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA.
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3
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Booth S, Hsieh A, Mostaco-Guidolin L, Koo HK, Wu K, Aminazadeh F, Yang CX, Quail D, Wei Y, Cooper JD, Paré PD, Hogg JC, Vasilescu DM, Hackett TL. A Single-Cell Atlas of Small Airway Disease in Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study. Am J Respir Crit Care Med 2023; 208:472-486. [PMID: 37406359 DOI: 10.1164/rccm.202303-0534oc] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 07/05/2023] [Indexed: 07/07/2023] Open
Abstract
Rationale: Emerging data demonstrate that the smallest conducting airways, terminal bronchioles, are the early site of tissue destruction in chronic obstructive pulmonary disease (COPD) and are reduced by as much as 41% by the time someone is diagnosed with mild (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 1) COPD. Objectives: To develop a single-cell atlas that describes the structural, cellular, and extracellular matrix alterations underlying terminal bronchiole loss in COPD. Methods: This cross-sectional study of 262 lung samples derived from 34 ex-smokers with normal lung function (n = 10) or GOLD stage 1 (n = 10), stage 2 (n = 8), or stage 4 (n = 6) COPD was performed to assess the morphology, extracellular matrix, single-cell atlas, and genes associated with terminal bronchiole reduction using stereology, micro-computed tomography, nonlinear optical microscopy, imaging mass spectrometry, and transcriptomics. Measurements and Main Results: The lumen area of terminal bronchioles progressively narrows with COPD severity as a result of the loss of elastin fibers within alveolar attachments, which was observed before microscopic emphysematous tissue destruction in GOLD stage 1 and 2 COPD. The single-cell atlas of terminal bronchioles in COPD demonstrated M1-like macrophages and neutrophils located within alveolar attachments and associated with the pathobiology of elastin fiber loss, whereas adaptive immune cells (naive, CD4, and CD8 T cells, and B cells) are associated with terminal bronchiole wall remodeling. Terminal bronchiole pathology was associated with the upregulation of genes involved in innate and adaptive immune responses, the interferon response, and the degranulation of neutrophils. Conclusions: This comprehensive single-cell atlas highlights terminal bronchiole alveolar attachments as the initial site of tissue destruction in centrilobular emphysema and an attractive target for disease modification.
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Affiliation(s)
- Steven Booth
- Centre for Heart Lung Innovation
- Department of Anesthesiology, Pharmacology and Therapeutics, and
| | - Aileen Hsieh
- Centre for Heart Lung Innovation
- Department of Anesthesiology, Pharmacology and Therapeutics, and
| | - Leila Mostaco-Guidolin
- Department of Systems and Computer Engineering, Carleton University, Ottawa, Ontario, Canada
| | - Hyun-Kyoung Koo
- Centre for Heart Lung Innovation
- Department of Anesthesiology, Pharmacology and Therapeutics, and
| | - Keith Wu
- Centre for Heart Lung Innovation
- Department of Anesthesiology, Pharmacology and Therapeutics, and
| | - Fatemeh Aminazadeh
- Centre for Heart Lung Innovation
- Department of Anesthesiology, Pharmacology and Therapeutics, and
| | | | - Daniela Quail
- Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Québec, Canada; and
| | - Yuhong Wei
- Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Québec, Canada; and
| | - Joel D Cooper
- Department of Thoracic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - James C Hogg
- Centre for Heart Lung Innovation
- Department of Pathology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dragoş M Vasilescu
- Centre for Heart Lung Innovation
- Department of Pathology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tillie-Louise Hackett
- Centre for Heart Lung Innovation
- Department of Anesthesiology, Pharmacology and Therapeutics, and
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4
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Gracioso Martins AM, Snider DB, Popowski KD, Schuchard KG, Tenorio M, Akunuri S, Wee J, Peters KJ, Jansson A, Shirwaiker R, Cheng K, Freytes DO, Cruse GP. Low-dose intrapulmonary drug delivery device for studies on next-generation therapeutics in mice. J Control Release 2023; 359:287-301. [PMID: 37301267 PMCID: PMC10527740 DOI: 10.1016/j.jconrel.2023.05.039] [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: 10/14/2022] [Revised: 05/16/2023] [Accepted: 05/27/2023] [Indexed: 06/12/2023]
Abstract
Although nebulizers have been developed for delivery of small molecules in human patients, no tunable device has been purpose-built for targeted delivery of modern large molecule and temperature-sensitive therapeutics to mice. Mice are used most of all species in biomedical research and have the highest number of induced models for human-relevant diseases and transgene models. Regulatory approval of large molecule therapeutics, including antibody therapies and modified RNA highlight the need for quantifiable dose delivery in mice to model human delivery, proof-of-concept studies, efficacy, and dose-response. To this end, we developed and characterized a tunable nebulization system composed of an ultrasonic transducer equipped with a mesh nebulizer fitted with a silicone restrictor plate modification to control the nebulization rate. We have identified the elements of design that influence the most critical factors to targeted delivery to the deep lungs of BALB/c mice. By comparing an in silico model of the mouse lung with experimental data, we were able to optimize and confirm the targeted delivery of over 99% of the initial volume to the deep portions of the mouse lung. The resulting nebulizer system provides targeted lung delivery efficiency far exceeding conventional nebulizers preventing waste of expensive biologics and large molecules during proof-of-concept and pre-clinical experiments involving mice. (Word Count =207).
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Affiliation(s)
- Ana Maria Gracioso Martins
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA; Joint Department of Biomedical Engineering, North Carolina State University & University of North Carolina-Chapel Hill, NC, USA
| | - Douglas B Snider
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; Comparative Medicine and Translational Research Training Program, North Carolina State University, Raleigh, NC, USA; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA
| | - Kristen D Popowski
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA; Joint Department of Biomedical Engineering, North Carolina State University & University of North Carolina-Chapel Hill, NC, USA
| | - Karl G Schuchard
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA; Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, Raleigh, NC, USA
| | - Matias Tenorio
- Joint Department of Biomedical Engineering, North Carolina State University & University of North Carolina-Chapel Hill, NC, USA
| | - Sandip Akunuri
- Joint Department of Biomedical Engineering, North Carolina State University & University of North Carolina-Chapel Hill, NC, USA
| | - Junghyun Wee
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, USA
| | - Kara J Peters
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, USA
| | - Anton Jansson
- Analytical Instrumentation Facility, Monteith Research Center, North Carolina State University, Raleigh, NC, USA
| | - Rohan Shirwaiker
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA; Joint Department of Biomedical Engineering, North Carolina State University & University of North Carolina-Chapel Hill, NC, USA; Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, Raleigh, NC, USA; Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, USA
| | - Ke Cheng
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA; Joint Department of Biomedical Engineering, North Carolina State University & University of North Carolina-Chapel Hill, NC, USA
| | - Donald O Freytes
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA; Joint Department of Biomedical Engineering, North Carolina State University & University of North Carolina-Chapel Hill, NC, USA
| | - Glenn P Cruse
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA.
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5
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Rabbani A, Babaei M, Gharib M. Automated segmentation and morphological characterization of placental intervillous space based on a single labeled image. Micron 2023; 169:103448. [PMID: 36965271 DOI: 10.1016/j.micron.2023.103448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/19/2023] [Accepted: 03/20/2023] [Indexed: 03/27/2023]
Abstract
In this study, a novel method of data augmentation has been presented for the segmentation of placental histological images when the labeled data are scarce. This method generates new realizations of the placenta intervillous morphology while maintaining the general textures and orientations. As a result, a diversified artificial dataset of images is generated that can be used for training deep learning segmentation models. We have observed that on average the presented method of data augmentation led to a 42% decrease in the binary cross-entropy loss of the validation dataset compared to the common approach in the literature. Additionally, the morphology of the intervillous space is studied under the effect of the proposed image reconstruction technique, and the diversity of the artificially generated population is quantified. We have demonstrated that the proposed method results in a more accurate morphological characterization of the placental intervillous space with an average feature relative error of 6.5%, which is significantly lower than the 11.5% error observed with conventional augmentation techniques. Due to the high resemblance of the generated images to the real ones, applications of the proposed method may not be limited to placental histological images, and it is recommended that other types of tissue be investigated in future studies.
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Affiliation(s)
- Arash Rabbani
- School of Computing, University of Leeds, Leeds, UK.
| | - Masoud Babaei
- School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, UK
| | - Masoumeh Gharib
- Department of Pathology, Mashhad University of Medical Sciences, Mashhad, Iran
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6
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Reimelt AM, Vasilescu DM, Beare R, Labode J, Knudsen L, Grothausmann R. Analysis of the alveolar shape in 3-D. Am J Physiol Lung Cell Mol Physiol 2023; 324:L358-L372. [PMID: 36719077 DOI: 10.1152/ajplung.00069.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Mechanical forces affect the alveolar shape, depending on location and tissue composition, and vary during the respiratory cycle. This study performs alveolar morphomics in different lobes of human lungs using models generated from three-dimensional (3-D) micro-computed tomography (microCT) images. Cylindrical tissue samples (1.6 cm × 2 cm) were extracted from two nontransplantable donor lungs (one ex-smoker and one smoker, 3 samples per subject) that were air-inflated and frozen solid in liquid nitrogen vapor. Samples were scanned with microCT (11 µm/voxel). Within representative cubic regions of interest (5.5 mm edge length), alveoli were segmented to produce corresponding 3-D models from which quantitative data were obtained. The surface of segmented alveoli (n_alv_total = 23,587) was divided into individual planar surfaces (facets) and angles between facet normals were calculated. Moreover, the number of neighboring alveoli was estimated for every alveolus. In this study, we examined intraindividual differences in alveolar morphology, which were reproducible in the lungs of two subjects. The main aspects are higher mean alveolar volumes (v_alv: 6.64 × 106 and 6.63 × 106 µm3 vs. 5.78 × 106 and 6.29 × 106 µm3) and surface sizes (s_alv: 0.19 and 0.18 mm2 vs. 0.17 mm2 in both lower lobes) in both upper lung lobes compared with the lower lobes. An increasing number of facets (f_alv) from top to bottom (12 and 14 in the upper lobes; 14 and 15 in the lower lobes), as well as a decreasing number of alveolar neighbors (nei_alv: 9 and 8 in the upper lobes; 8 and 7 in the lower lobes) from the upper lobes to the lower lobes were observed. We could observe an increasing ratio of alveolar entrance size to the surface size of the alveoli from top to bottom (S_ratio_alv: 0.71 and 0.64 in the upper lobes, 0.73 and 0.70 in the lower lobes). The angles between facet normals (ang_alv) were larger in the upper lobes (67.72° and 62.44°) of both lungs than in the lower lobes (66.19° and 61.30°). By using this new approach of analyzing alveolar 3-D data, which enables the estimation of facet, neighbor, and shape characteristics, we aimed to establish the baseline measures for in-depth studies of mechanical conditions and morphology.
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Affiliation(s)
- Alex M Reimelt
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Dragoș M Vasilescu
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Richard Beare
- Academic Unit, Medicine, Peninsula Clinical School, Monash University, Melbourne, Victoria, Australia.,Developmental Imaging, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Jonas Labode
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Roman Grothausmann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Faculty of Engineering and Health, HAWK University of Applied Sciences and Arts, Göttingen, Germany
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7
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Neelakantan S, Ismail MK, Mukherjee T, Smith BJ, Rizi R, Avazmohammadi R. Volumetric versus distortional deformation in rat lungs. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2023; 12466:124661R. [PMID: 37565032 PMCID: PMC10414622 DOI: 10.1117/12.2653648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
There are several lung diseases that lead to alterations in regional lung mechanics, including acute respiratory distress syndrome. Such alterations can lead to localized underventilation of the affected areas resulting in the overdistension of the surrounding healthy regions. They can also lead to the surrounding alveoli expanding unevenly or distorting. Therefore, the quantification of the regional deformation in the lungs offers insights into identifying the regions at risk of lung injury. Although few recent studies have developed image processing techniques to quantify the regional volumetric deformation in the lung from dynamic imaging, the presence and extent of distortional deformation in the lung, and its correlation with volumetric deformation, remain poorly understood. In this study, we present a method that uses the four-dimensional displacement field obtained from image registration to quantify both regional volumetric and distortional deformation in the lung. We used dynamic computed tomography scans in a healthy rat over the course of one respiratory cycle in free breathing. Non-rigid image registration was performed to quantify voxel displacement during respiration. The deformation gradient was calculated using the displacement field and its determinant was used to quantify regional volumetric deformation. Regional distortion was calculated as the ratio of maximum to minimum principal stretches using the isochoric part of the Cauchy green tensor. We found an inverse correlation between volumetric strains and distortion indicating that poorly expanding alveoli tend to experience larger distortion. The combination of regional volumetric strains and distortion may serve as high-fidelity biomarkers to identify the regions at risk of most adverse lung injuries.
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Affiliation(s)
- Sunder Neelakantan
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Mostafa K Ismail
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Tanmay Mukherjee
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Bradford J Smith
- Department of Bioengineering, University of Colorado Denver | Anschutz Medical Campus, Aurora, CO, USA
- Department of Pediatric Pulmonary and Sleep Medicine, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Rahim Rizi
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Reza Avazmohammadi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA
- Department of Cardiovascular Sciences, Houston Methodist Academic Institute, Houston, TX, USA
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8
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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.
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9
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Neelakantan S, Xin Y, Gaver DP, Cereda M, Rizi R, Smith BJ, Avazmohammadi R. Computational lung modelling in respiratory medicine. J R Soc Interface 2022; 19:20220062. [PMID: 35673857 PMCID: PMC9174712 DOI: 10.1098/rsif.2022.0062] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Computational modelling of the lungs is an active field of study that integrates computational advances with lung biophysics, biomechanics, physiology and medical imaging to promote individualized diagnosis, prognosis and therapy evaluation in lung diseases. The complex and hierarchical architecture of the lung offers a rich, but also challenging, research area demanding a cross-scale understanding of lung mechanics and advanced computational tools to effectively model lung biomechanics in both health and disease. Various approaches have been proposed to study different aspects of respiration, ranging from compartmental to discrete micromechanical and continuum representations of the lungs. This article reviews several developments in computational lung modelling and how they are integrated with preclinical and clinical data. We begin with a description of lung anatomy and how different tissue components across multiple length scales affect lung mechanics at the organ level. We then review common physiological and imaging data acquisition methods used to inform modelling efforts. Building on these reviews, we next present a selection of model-based paradigms that integrate data acquisitions with modelling to understand, simulate and predict lung dynamics in health and disease. Finally, we highlight possible future directions where computational modelling can improve our understanding of the structure–function relationship in the lung.
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Affiliation(s)
- Sunder Neelakantan
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Yi Xin
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Donald P. Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Rahim Rizi
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Bradford J. Smith
- Department of Bioengineering, University of Colorado Denver
- Anschutz Medical Campus, Aurora, CO, USA
- Department of Pediatric Pulmonary and Sleep Medicine, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Reza Avazmohammadi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA
- Department of Cardiovascular Sciences, Houston Methodist Academic Institute, Houston, TX, USA
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10
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Hoffman EA. Origins of and lessons from quantitative functional X-ray computed tomography of the lung. Br J Radiol 2022; 95:20211364. [PMID: 35193364 PMCID: PMC9153696 DOI: 10.1259/bjr.20211364] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/20/2022] [Accepted: 01/27/2022] [Indexed: 12/16/2022] Open
Abstract
Functional CT of the lung has emerged from quantitative CT (qCT). Structural details extracted at multiple lung volumes offer indices of function. Additionally, single volumetric images, if acquired at standardized lung volumes and body posture, can be used to model function by employing such engineering techniques as computational fluid dynamics. With the emergence of multispectral CT imaging including dual energy from energy integrating CT scanners and multienergy binning using the newly released photon counting CT technology, function is tagged via use of contrast agents. Lung disease phenotypes have previously been lumped together by the limitations of spirometry and plethysmography. QCT and its functional embodiment have been imbedded into studies seeking to characterize chronic obstructive pulmonary disease, severe asthma, interstitial lung disease and more. Reductions in radiation dose by an order of magnitude or more have been achieved. At the same time, we have seen significant increases in spatial and density resolution along with methodologic validations of extracted metrics. Together, these have allowed attention to turn towards more mild forms of disease and younger populations. In early applications, clinical CT offered anatomic details of the lung. Functional CT offers regional measures of lung mechanics, the assessment of functional small airways disease, as well as regional ventilation-perfusion matching (V/Q) and more. This paper will focus on the use of quantitative/functional CT for the non-invasive exploration of dynamic three-dimensional functioning of the breathing lung and beating heart within the unique negative pressure intrathoracic environment of the closed chest.
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Affiliation(s)
- Eric A Hoffman
- Departments of Radiology, Internal Medicine and Biomedical Engineering University of Iowa, Iowa, United States
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11
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Tanabe N, Hirai T. Recent advances in airway imaging using micro-computed tomography and computed tomography for chronic obstructive pulmonary disease. Korean J Intern Med 2021; 36:1294-1304. [PMID: 34607419 PMCID: PMC8588974 DOI: 10.3904/kjim.2021.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/14/2021] [Indexed: 12/13/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a complex lung disease characterized by a combination of airway disease and emphysema. Emphysema is classified as centrilobular emphysema (CLE), paraseptal emphysema (PSE), or panlobular emphysema (PLE), and airway disease extends from the respiratory, terminal, and preterminal bronchioles to the central segmental airways. Although clinical computed tomography (CT) cannot be used to visualize the small airways, micro-CT has shown that terminal bronchiole disease is more severe in CLE than in PSE and PLE, and micro-CT findings suggest that the loss and luminal narrowing of terminal bronchioles is an early pathological change in CLE. Furthermore, the introduction of ultra-high-resolution CT has enabled direct evaluation of the proximal small (1 to 2-mm diameter) airways, and new CT analytical methods have enabled estimation of small airway disease and prediction of future COPD onset and lung function decline in smokers with and without COPD. This review discusses the literature on micro-CT and the technical advancements in clinical CT analysis for COPD. Hopefully, novel micro-CT findings will improve our understanding of the distinct pathogeneses of the emphysema subtypes to enable exploration of new therapeutic targets, and sophisticated CT imaging methods will be integrated into clinical practice to achieve more personalized management.
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Affiliation(s)
- Naoya Tanabe
- Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toyohiro Hirai
- Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
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12
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Balasch A, Metze P, Li H, Rottbauer W, Abaei A, Rasche V. Tiny golden angle ultrashort echo-time lung imaging in mice. NMR IN BIOMEDICINE 2021; 34:e4591. [PMID: 34322941 DOI: 10.1002/nbm.4591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 06/25/2021] [Accepted: 07/04/2021] [Indexed: 06/13/2023]
Abstract
Imaging the lung parenchyma with MRI is particularly difficult in small animals due to the high respiratory and heart rates, and ultrashort T2* at high magnetic field strength caused by the high susceptibilities induced by the air-tissue interfaces. In this study, a 2D ultrashort echo-time (UTE) technique was combined with tiny golden angle (tyGA) ordering. Data were acquired continuously at 11.7 T and retrospective center-of-k-space gating was applied to reconstruct respiratory multistage images. Lung (proton) density (fP ), T2*, signal-to-noise ratio (SNR), fractional ventilation (FV) and perfusion (f) were quantified, and the application to dynamic contrast agent (CA)-enhanced (DCE) qualitative perfusion assessment tested. The interobserver and intraobserver and interstudy reproducibility of the quantitative parameters were investigated. High-quality images of the lung parenchyma could be acquired in all animals. Over all lung regions a mean T2* of 0.20 ± 0.05 ms was observed. FV resulted as 0.31 ± 0.13, and a trend towards lower SNR values during inspiration (EX: SNR = 12.48 ± 6.68, IN: SNR = 11.79 ± 5.86) and a significant (P < 0.001) decrease in lung density (EX: fP = 0.69 ± 0.13, IN: fP = 0.62 ± 0.13) were observed. Quantitative perfusion results as 34.63 ± 9.05 mL/cm3 /min (systole) and 32.77 ± 8.55 mL/cm3 /min (diastole) on average. The CA dynamics could be assessed and, because of the continuous nature of the data acquisition, reconstructed at different temporal resolutions. Where a good to excellent interobserver reproducibility and an excellent intraobserver reproducibility resulted, the interstudy reproducibility was only fair to good. In conclusion, the combination of tiny golden angles with UTE (2D tyGA UTE) resulted in a reliable imaging technique for lung morphology and function in mice, providing uniform k-space coverage and thus low-artefact images of the lung parenchyma after gating.
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Affiliation(s)
- Anke Balasch
- Department of Internal Medicine II, Ulm University Medical Centre, Ulm, Germany
| | - Patrick Metze
- Department of Internal Medicine II, Ulm University Medical Centre, Ulm, Germany
| | - Hao Li
- Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Cardiac Electrophysiology and Arrhythmia, People's Republic of China
- Core Facility Small Animal Imaging (CF-SANI), Ulm University, Ulm, Germany
| | - Wolfgang Rottbauer
- Department of Internal Medicine II, Ulm University Medical Centre, Ulm, Germany
| | - Alireza Abaei
- Core Facility Small Animal Imaging (CF-SANI), Ulm University, Ulm, Germany
| | - Volker Rasche
- Department of Internal Medicine II, Ulm University Medical Centre, Ulm, Germany
- Core Facility Small Animal Imaging (CF-SANI), Ulm University, Ulm, Germany
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13
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Ikezoe K, Hackett TL, Peterson S, Prins D, Hague CJ, Murphy D, LeDoux S, Chu F, Xu F, Cooper JD, Tanabe N, Ryerson CJ, Paré PD, Coxson HO, Colby TV, Hogg JC, Vasilescu DM. Small Airway Reduction and Fibrosis is an Early Pathologic Feature of Idiopathic Pulmonary Fibrosis. Am J Respir Crit Care Med 2021; 204:1048-1059. [PMID: 34343057 DOI: 10.1164/rccm.202103-0585oc] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE To improve disease outcomes in idiopathic pulmonary fibrosis (IPF) it is essential to understand its early pathophysiology so that it can be targeted therapeutically. OBJECTIVES Perform three-dimensional (3D) assessment of the IPF lung micro-structure using stereology and multi-resolution computed tomography (CT) imaging. METHODS Explanted lungs from IPF patients (n=8) and donor controls (n=8) were inflated with air and frozen. CT scans were used to assess large airways. Unbiased, systematic uniform random (SUR) samples (n=8/lung) were scanned with microCT for stereological assessment of small airways (number, airway wall and lumen area) and parenchymal fibrosis (volume fraction of tissue, alveolar surface area, and septal wall thickness). RESULTS The total number of airways on clinical CT was greater in IPF lungs than control lungs (p<0.01), due to an increase in the wall (p<0.05) and lumen area (p<0.05) resulting in more visible airways with a lumen larger than 2 mm. In IPF tissue samples without microscopic fibrosis, assessed by the volume fraction of tissue using microCT, there was a reduction in the number of the terminal (p<0.01) and transitional (p<0.001) bronchioles, and an increase in terminal bronchiole wall area (p<0.001) compared to control lungs. In IPF tissue samples with microscopic parenchymal fibrosis, terminal bronchioles had increased airway wall thickness (p<0.05), and dilated airway lumens (p<0.001) leading to honeycomb cyst formations. CONCLUSION This study has important implications for the current thinking on how the lung tissue is remodeled in IPF, and highlights small airways as a potential target to modify IPF outcomes.
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Affiliation(s)
- Kohei Ikezoe
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada
| | - Tillie-Louise Hackett
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada
| | | | - Dante Prins
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada
| | - Cameron J Hague
- The University of British Columbia Department of Radiology, 478400, Vancouver, British Columbia, Canada
| | - Darra Murphy
- The University of British Columbia Department of Radiology, 478400, Vancouver, British Columbia, Canada
| | - Stacey LeDoux
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada
| | - Fanny Chu
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada
| | - Feng Xu
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Pathology and Lab Medicine, Vancouver, British Columbia, Canada
| | - Joel D Cooper
- University of Pennsylvania, 6572, Thoracic surgery, Philadelphia, Pennsylvania, United States
| | - Naoya Tanabe
- Kyoto University Graduate School of Medicine Department of Respiratory Medicine, 215651, Kyoto, Japan
| | - Christopher J Ryerson
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Medicine, Vancouver, British Columbia, Canada
| | - Peter D Paré
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada
| | - Harvey O Coxson
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada
| | - Thomas V Colby
- Mayo Clinic Department of Laboratory Medicine and Pathology, 195112, Rochester, Minnesota, United States
| | - James C Hogg
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada
| | - Dragoş M Vasilescu
- The University of British Columbia Centre for Heart Lung Innovation, 539747, Vancouver, British Columbia, Canada;
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14
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Mühlfeld C. Stereology and three-dimensional reconstructions to analyze the pulmonary vasculature. Histochem Cell Biol 2021; 156:83-93. [PMID: 34272602 PMCID: PMC8397636 DOI: 10.1007/s00418-021-02013-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2021] [Indexed: 02/05/2023]
Abstract
The pulmonary vasculature consists of a large arterial and venous tree with a vast alveolar capillary network (ACN) in between. Both conducting blood vessels and the gas-exchanging capillaries are part of important human lung diseases, including bronchopulmonary dysplasia, pulmonary hypertension and chronic obstructive pulmonary disease. Morphological tools to investigate the different parts of the pulmonary vasculature quantitatively and in three dimensions are crucial for a better understanding of the contribution of the blood vessels to the pathophysiology and effects of lung diseases. In recent years, new stereological methods and imaging techniques have expanded the analytical tool box and therefore the conclusive power of morphological analyses of the pulmonary vasculature. Three of these developments are presented and discussed in this review article, namely (1) stereological quantification of the number of capillary loops, (2) serial block-face scanning electron microscopy of the ACN and (3) labeling of branching generations in light microscopic sections based on arterial tree segmentations of micro-computed tomography data sets of whole lungs. The implementation of these approaches in research work requires expertise in lung preparation, multimodal imaging at different scales, an advanced IT infrastructure and expertise in image analysis. However, they are expected to provide important data that cannot be obtained by previously existing methodology.
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Affiliation(s)
- Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany. .,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany. .,Research Core Unit Electron Microscopy, Hannover Medical School, 30625, Hannover, Germany.
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15
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Combination of µCT and light microscopy for generation-specific stereological analysis of pulmonary arterial branches: a proof-of-concept study. Histochem Cell Biol 2020; 155:227-239. [PMID: 33263790 PMCID: PMC7709482 DOI: 10.1007/s00418-020-01946-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2020] [Indexed: 12/21/2022]
Abstract
Various lung diseases, including pulmonary hypertension, chronic obstructive pulmonary disease or bronchopulmonary dysplasia, are associated with structural and architectural alterations of the pulmonary vasculature. The light microscopic (LM) analysis of the blood vessels is limited by the fact that it is impossible to identify which generation of the arterial tree an arterial profile within a LM microscopic section belongs to. Therefore, we established a workflow that allows for the generation-specific quantitative (stereological) analysis of pulmonary blood vessels. A whole left rabbit lung was fixed by vascular perfusion, embedded in glycol methacrylate and imaged by micro-computed tomography (µCT). The lung was then exhaustively sectioned and 20 consecutive sections were collected every 100 µm to obtain a systematic uniform random sample of the whole lung. The digital processing involved segmentation of the arterial tree, generation analysis, registration of LM sections with the µCT data as well as registration of the segmentation and the LM images. The present study demonstrates that it is feasible to identify arterial profiles according to their generation based on a generation-specific color code. Stereological analysis for the first three arterial generations of the monopodial branching of the vasculature included volume fraction, total volume, lumen-to-wall ratio and wall thickness for each arterial generation. In conclusion, the correlative image analysis of µCT and LM-based datasets is an innovative method to assess the pulmonary vasculature quantitatively.
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16
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Knudsen L, Brandenberger C, Ochs M. Stereology as the 3D tool to quantitate lung architecture. Histochem Cell Biol 2020; 155:163-181. [PMID: 33051774 PMCID: PMC7910236 DOI: 10.1007/s00418-020-01927-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2020] [Indexed: 01/12/2023]
Abstract
Stereology is the method of choice for the quantitative assessment of biological objects in microscopy. It takes into account the fact that, in traditional microscopy such as conventional light and transmission electron microscopy, although one has to rely on measurements on nearly two-dimensional sections from fixed and embedded tissue samples, the quantitative data obtained by these measurements should characterize the real three-dimensional properties of the biological objects and not just their “flatland” appearance on the sections. Thus, three-dimensionality is a built-in property of stereological sampling and measurement tools. Stereology is, therefore, perfectly suited to be combined with 3D imaging techniques which cover a wide range of complementary sample sizes and resolutions, e.g. micro-computed tomography, confocal microscopy and volume electron microscopy. Here, we review those stereological principles that are of particular relevance for 3D imaging and provide an overview of applications of 3D imaging-based stereology to the lung in health and disease. The symbiosis of stereology and 3D imaging thus provides the unique opportunity for unbiased and comprehensive quantitative characterization of the three-dimensional architecture of the lung from macro to nano scale.
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Affiliation(s)
- Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.,REBIRTH Cluster of Excellence, Hannover, Germany
| | - Christina Brandenberger
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.,REBIRTH Cluster of Excellence, Hannover, Germany
| | - Matthias Ochs
- Institute of Functional Anatomy, Charité-Universitätsmedizin Berlin, Philippstr. 11, 10115, Berlin, Germany. .,German Center for Lung Research (DZL), Berlin, Germany.
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17
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Salaets T, Tack B, Gie A, Pavie B, Sindhwani N, Jimenez J, Regin Y, Allegaert K, Deprest J, Toelen J. A semi-automated method for unbiased alveolar morphometry: Validation in a bronchopulmonary dysplasia model. PLoS One 2020; 15:e0239562. [PMID: 32966330 PMCID: PMC7511023 DOI: 10.1371/journal.pone.0239562] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/08/2020] [Indexed: 11/18/2022] Open
Abstract
Reproducible and unbiased methods to quantify alveolar structure are important for research on many lung diseases. However, manually estimating alveolar structure through stereology is time consuming and inter-observer variability is high. The objective of this work was to develop and validate a fast, reproducible and accurate (semi-)automatic alternative. A FIJI-macro was designed that automatically segments lung images to binary masks, and counts the number of test points falling on tissue and the number of intersections of the air-tissue interface with a set of test lines. Manual selection remains necessary for the recognition of non-parenchymal tissue and alveolar exudates. Volume density of alveolar septa ( VVsep) and mean linear intercept of the airspaces (Lm) as measured by the macro were compared to theoretical values for 11 artificial test images and to manually counted values for 17 lungs slides using linear regression and Bland-Altman plots. Inter-observer agreement between 3 observers, measuring 8 lungs both manually and automatically, was assessed using intraclass correlation coefficients (ICC). VVsep and Lm measured by the macro closely approached theoretical values for artificial test images (R2 of 0.9750 and 0.9573 and bias of 0.34% and 8.7%). The macro data in lungs were slightly higher for VVsep and slightly lower for Lm in comparison to manually counted values (R2 of 0.8262 and 0.8288 and bias of -6.0% and 12.1%). Visually, semi-automatic segmentation was accurate. Most importantly, manually counted VVsep and Lm had only moderate to good inter-observer agreement (ICC 0.859 and 0.643), but agreements were excellent for semi-automatically counted values (ICC 0.956 and 0.900). This semi-automatic method provides accurate and highly reproducible alveolar morphometry results. Future efforts should focus on refining methods for automatic detection of non-parenchymal tissue or exudates, and for assessment of lung structure on 3D reconstructions of lungs scanned with microCT.
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Affiliation(s)
- Thomas Salaets
- Department of Development and Regeneration, KULeuven, Leuven, Belgium
- Department of Pediatrics, UZ Leuven, Leuven, Belgium
- * E-mail:
| | - Bieke Tack
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - André Gie
- Department of Development and Regeneration, KULeuven, Leuven, Belgium
| | - Benjamin Pavie
- Department of Imaging and Pathology, KULeuven, Leuven, Belgium
| | - Nikhil Sindhwani
- Department of Development and Regeneration, KULeuven, Leuven, Belgium
| | - Julio Jimenez
- Facultad de Medicina, Universidad del Desarollo, Clínica Alemana, Santiago de Chile, Chile
| | - Yannick Regin
- Department of Development and Regeneration, KULeuven, Leuven, Belgium
| | - Karel Allegaert
- Department of Pharmaceutical and Pharmacological Sciences, KULeuven, Leuven, Belgium
- Department of Clinical Pharmacy, Erasmus MC, Rotterdam, The Netherlands
| | - Jan Deprest
- Department of Development and Regeneration, KULeuven, Leuven, Belgium
- Department of Obstetrics and Gynecology, UZ Leuven, Leuven, Belgium
- Institute for Women’s Health, University College London Hospital, London, United Kingdom
| | - Jaan Toelen
- Department of Development and Regeneration, KULeuven, Leuven, Belgium
- Department of Pediatrics, UZ Leuven, Leuven, Belgium
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18
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Verleden SE, Tanabe N, McDonough JE, Vasilescu DM, Xu F, Wuyts WA, Piloni D, De Sadeleer L, Willems S, Mai C, Hostens J, Cooper JD, Verbeken EK, Verschakelen J, Galban CJ, Van Raemdonck DE, Colby TV, Decramer M, Verleden GM, Kaminski N, Hackett TL, Vanaudenaerde BM, Hogg JC. Small airways pathology in idiopathic pulmonary fibrosis: a retrospective cohort study. THE LANCET. RESPIRATORY MEDICINE 2020; 8:573-584. [PMID: 32061334 PMCID: PMC7292784 DOI: 10.1016/s2213-2600(19)30356-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/09/2019] [Accepted: 09/11/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND The observation that patients with idiopathic pulmonary fibrosis (IPF) can have higher than normal expiratory flow rates at low lung volumes led to the conclusion that the airways are spared in IPF. This study aimed to re-examine the hypothesis that airways are spared in IPF using a multiresolution imaging protocol that combines multidetector CT (MDCT), with micro-CT and histology. METHODS This was a retrospective cohort study comparing explanted lungs from patients with severe IPF treated by lung transplantation with a cohort of unused donor (control) lungs. The donor control lungs had no known lung disease, comorbidities, or structural lung injury, and were deemed appropriate for transplantation on review of the clinical files. The diagnosis of IPF in the lungs from patients was established by a multidisciplinary consensus committee according to existing guidelines, and was confirmed by video-assisted thoracic surgical biopsy or by pathological examination of the contralateral lung. The control and IPF groups were matched for age, sex, height, and bodyweight. Samples of lung tissue were compared using the multiresolution imaging approach: a cascade of clinical MDCT, micro-CT, and histological imaging. We did two experiments: in experiment 1, all the lungs were randomly sampled; in experiment 2, samples were selected from regions of minimal and established fibrosis. The patients and donors were recruited from the Katholieke Universiteit Leuven (Leuven, Belgium) and the University of Pennsylvania Hospital (Philadelphia, PA, USA). The study took place at the Katholieke Universiteit Leuven, and the University of British Columbia (Vancouver, BC, Canada). FINDINGS Between Oct 5, 2009, and July 22, 2016, explanted lungs from patients with severe IPF (n=11), were compared with a cohort of unused donor (control) lungs (n=10), providing 240 samples of lung tissue for comparison using the multiresolution imaging approach. The MDCT specimen scans show that the number of visible airways located between the ninth generation (control 69 [SD 22] versus patients with IPF 105 [33], p=0·0023) and 14th generation (control 9 [6] versus patients with IPF 49 [28], p<0·0001) of airway branching are increased in patients with IPF, which we show by micro-CT is due to thickening of their walls and distortion of their lumens. The micro-CT analysis showed that compared with healthy (control) lung anatomy (mean 5·6 terminal bronchioles per mL [SD 1·6]), minimal fibrosis in IPF tissue was associated with a 57% loss of the terminal bronchioles (mean 2·4 terminal bronchioles per mL [SD 1·0]; p<0·0001), the appearance of fibroblastic foci, and infiltration of the tissue by inflammatory immune cells capable of forming lymphoid follicles. Established fibrosis in IPF tissue had a similar reduction (66%) in the number of terminal bronchioles (mean 1·9 terminal bronchioles per mL [SD 1·4]; p<0·0001) and was dominated by increased airspace size, Ashcroft fibrosis score, and volume fractions of tissue and collagen. INTERPRETATION Small airways disease is a feature of IPF, with significant loss of terminal bronchioles occuring within regions of minimal fibrosis. On the basis of these findings, we postulate that the small airways could become a potential therapeutic target in IPF. FUNDING Katholieke Universiteit Leuven, US National Institutes of Health, BC Lung Association, and Genentech.
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Affiliation(s)
- Stijn E Verleden
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Naoya Tanabe
- University of British Columbia, Department of Pathology and Center for Heart and Lung Innovation at St Paul's Hospital, Vancouver, BC, Canada; Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - John E McDonough
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Dragoş M Vasilescu
- University of British Columbia, Department of Pathology and Center for Heart and Lung Innovation at St Paul's Hospital, Vancouver, BC, Canada
| | - Feng Xu
- University of British Columbia, Department of Pathology and Center for Heart and Lung Innovation at St Paul's Hospital, Vancouver, BC, Canada
| | - Wim A Wuyts
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Davide Piloni
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium; The Respiratory Disease Unit, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy
| | - Laurens De Sadeleer
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Stijn Willems
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Cindy Mai
- Department of Radiology, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | | | - Joel D Cooper
- Department of Thoracic Surgery University of Pennsylvania, Philadelphia, PA, USA
| | - Erik K Verbeken
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Johny Verschakelen
- Department of Radiology, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Craig J Galban
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Dirk E Van Raemdonck
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Thomas V Colby
- Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, Phoenix, AZ, USA
| | - Marc Decramer
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Geert M Verleden
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - Naftali Kaminski
- Section of Pulmonary, Critical Care and Sleep Medicine, Yale University, New Haven, CT, USA
| | - Tillie-Louise Hackett
- University of British Columbia, Department of Pathology and Center for Heart and Lung Innovation at St Paul's Hospital, Vancouver, BC, Canada
| | - Bart M Vanaudenaerde
- Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, Katholieke Universiteit Leuven, University Hospitals Leuven, Leuven, Belgium
| | - James C Hogg
- University of British Columbia, Department of Pathology and Center for Heart and Lung Innovation at St Paul's Hospital, Vancouver, BC, Canada.
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Vasilescu DM, Phillion AB, Kinose D, Verleden SE, Vanaudenaerde BM, Verleden GM, Van Raemdonck D, Stevenson CS, Hague CJ, Han MK, Cooper JD, Hackett TL, Hogg JC. Comprehensive stereological assessment of the human lung using multiresolution computed tomography. J Appl Physiol (1985) 2020; 128:1604-1616. [PMID: 32298211 DOI: 10.1152/japplphysiol.00803.2019] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The application of stereology to lung casts and two-dimensional microscopy images is the gold standard for quantification of the human lung anatomy. However, these techniques are labor intensive, involving fixation, embedding, and histological sectioning of samples and thus have prevented comprehensive studies. Our objective was to demonstrate the application of stereology to volumetric multiresolution computed tomography (CT) to efficiently and extensively quantify the human lung anatomy. Nontransplantable donor lungs from individuals with no evidence of respiratory disease (n = 13) were air inflated, frozen at 10 cmH2O, and scanned using CT. Systematic uniform random samples were taken, scanned using micro-CT, and assessed using stereology. The application of stereology to volumetric CT imaging enabled comprehensive quantification of total lung volume, volume fractions of alveolar, alveolar duct, and tissue, mean linear intercept, alveolar surface area, alveolar surface area density, septal wall thickness, alveolar number, number-weighted mean alveolar volume, and the number and morphometry of terminal and transitional bronchioles. With the use of this data set, we found that women and men have the same number of terminal bronchioles (last generation of conducting airways), but men have longer terminal bronchioles, a smaller wall area percentage, and larger lungs due to a greater number of alveoli per acinus. The application of stereology to multiresolution CT imaging enables comprehensive analysis of the human lung parenchyma that identifies differences between men and women. The reported data set of normal donor lungs aged 25-77 yr provides reference data for future studies of chronic lung disease to determine exact changes in tissue pathology.NEW & NOTEWORTHY Stereology has been the gold standard to quantify the three-dimensional lung anatomy using two-dimensional microscopy images. However, such techniques are labor intensive. This study provides a method that applies stereology to volumetric computed tomography images of frozen whole human lungs and systematic uniform random samples. The method yielded a comprehensive data set on the small airways and parenchymal lung structures, highlighting morphometric sex differences and providing a reference data set for future pathological studies.
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Affiliation(s)
- Dragoş M Vasilescu
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver, British Columbia, Canada
| | - André B Phillion
- Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Daisuke Kinose
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stijn E Verleden
- Leuven Lung Transplant Unit, Katholieke Universiteit Leuven and Universitair Ziekenhuis Leuven-Gasthuisberg, Leuven, Belgium
| | - Bart M Vanaudenaerde
- Leuven Lung Transplant Unit, Katholieke Universiteit Leuven and Universitair Ziekenhuis Leuven-Gasthuisberg, Leuven, Belgium
| | - Geert M Verleden
- Leuven Lung Transplant Unit, Katholieke Universiteit Leuven and Universitair Ziekenhuis Leuven-Gasthuisberg, Leuven, Belgium
| | - Dirk Van Raemdonck
- Leuven Lung Transplant Unit, Katholieke Universiteit Leuven and Universitair Ziekenhuis Leuven-Gasthuisberg, Leuven, Belgium
| | | | - Cameron J Hague
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - MeiLan K Han
- Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, Michigan
| | - Joel D Cooper
- Division of Thoracic Surgery, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Tillie-Louise Hackett
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver, British Columbia, Canada
| | - James C Hogg
- Centre for Heart Lung Innovation, University of British Columbia, Vancouver, British Columbia, Canada
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Vasilescu DM, Martinez FJ, Marchetti N, Galbán CJ, Hatt C, Meldrum CA, Dass C, Tanabe N, Reddy RM, Lagstein A, Ross BD, Labaki WW, Murray S, Meng X, Curtis JL, Hackett TL, Kazerooni EA, Criner GJ, Hogg JC, Han MK. Noninvasive Imaging Biomarker Identifies Small Airway Damage in Severe Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Med 2019; 200:575-581. [PMID: 30794432 PMCID: PMC6727153 DOI: 10.1164/rccm.201811-2083oc] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 02/21/2019] [Indexed: 02/02/2023] Open
Abstract
Rationale: Evidence suggests damage to small airways is a key pathologic lesion in chronic obstructive pulmonary disease (COPD). Computed tomography densitometry has been demonstrated to identify emphysema, but no such studies have been performed linking an imaging metric to small airway abnormality.Objectives: To correlate ex vivo parametric response mapping (PRM) analysis to in vivo lung tissue measurements of patients with severe COPD treated by lung transplantation and control subjects.Methods: Resected lungs were inflated, frozen, and systematically sampled, generating 33 COPD (n = 11 subjects) and 22 control tissue samples (n = 3 subjects) for micro-computed tomography analysis of terminal bronchioles (TBs; last generation of conducting airways) and emphysema.Measurements and Main Results: PRM analysis was conducted to differentiate functional small airways disease (PRMfSAD) from emphysema (PRMEmph). In COPD lungs, TB numbers were reduced (P = 0.01); surviving TBs had increased wall area percentage (P < 0.001), decreased circularity (P < 0.001), reduced cross-sectional luminal area (P < 0.001), and greater airway obstruction (P = 0.008). COPD lungs had increased airspace size (P < 0.001) and decreased alveolar surface area (P < 0.001). Regression analyses demonstrated unique correlations between PRMfSAD and TBs, with decreased circularity (P < 0.001), decreased luminal area (P < 0.001), and complete obstruction (P = 0.008). PRMEmph correlated with increased airspace size (P < 0.001), decreased alveolar surface area (P = 0.003), and fewer alveolar attachments per TB (P = 0.01).Conclusions: PRMfSAD identifies areas of lung tissue with TB loss, luminal narrowing, and obstruction. This is the first confirmation that an imaging biomarker can identify terminal bronchial pathology in established COPD and provides a noninvasive imaging methodology to identify small airway damage in COPD.
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Affiliation(s)
| | | | - Nathaniel Marchetti
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | | | - Charles Hatt
- University of Michigan, Ann Arbor, Michigan
- Imbio, Minneapolis, Minnesota
| | | | - Chandra Dass
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | | | | | | | | | | | | | - Xia Meng
- University of British Columbia, Vancouver, British Columbia, Canada
- Weill Cornell Medical College, New York, New York
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
- University of Michigan, Ann Arbor, Michigan
- Imbio, Minneapolis, Minnesota
- Kyoto University, Kyoto, Japan; and
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan
| | - Jeffrey L. Curtis
- University of Michigan, Ann Arbor, Michigan
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan
| | | | | | - Gerard J. Criner
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - James C. Hogg
- University of British Columbia, Vancouver, British Columbia, Canada
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Evidence of CD40L/CD40 pathway involvement in experimental transfusion-related acute lung injury. Sci Rep 2019; 9:12536. [PMID: 31467410 PMCID: PMC6715651 DOI: 10.1038/s41598-019-49040-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 08/05/2019] [Indexed: 01/04/2023] Open
Abstract
Platelet transfusions can cause adverse reactions in their recipients, including transfusion-related acute lung injury (TRALI). The pathophysiology of TRALI depends on a number of signaling pathways and the inflammatory role played by blood platelets remains controversial. Platelets are important in inflammation, particularly via the immunomodulator complex CD40/CD40L. We studied the specific function of the CD40/CD40L interaction in regulating an experimental TRALI Two-hit model. A mouse model of immune TRALI was triggered by injection of LPS and an anti-MHC I antibody, and the effect of injection of a neutralizing anti-CD40L antibody before induction of TRALI investigated. The characteristics of TRALI were decreased body temperature, pulmonary lesions, and immune cell infiltration into the alveolar space. Pulmonary infiltration was evaluated by blood counts of specific immune cells and their detection in lung sections. Inhibition of the CD40/CD40L immunomodulator interaction significantly reduced communication between immune and/or endothelial cells and the development of pulmonary edema. Hence, our results indicate that targeting of the CD40/CD40L interaction could be an important method to prevent TRALI. While considering that our work concerned a mouse model, we postulate that improvement of the conditions under which platelet concentrates are prepared/stored would assist in alleviating the risk of TRALI.
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LIU TIANYA, WANG YUXING, LIU XIAOYU, YUAN LAN, LI DEYU, QIAO HUITING, FAN YUBO. EFFECTS OF ALVEOLAR MORPHOLOGY ON ALVEOLAR MECHANICS: AN EXPERIMENTAL STUDY OF MOUSE LUNG BASED ON TWO- AND THREE-DIMENSIONAL IMAGING METHODS. J MECH MED BIOL 2019. [DOI: 10.1142/s0219519419500271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Understanding alveolar mechanics is important for preventing the possible lung injuries during mechanical ventilation. Alveolar clusters with smaller size are found having lower compliance in two-dimensional studies. But the influence of alveolar shape on compliance is unclear. In order to investigate how alveolar morphology affects their behavior, we tracked subpleural alveoli of isolated mouse lungs during quasi-static ventilation using two- and three-dimensional imaging techniques. Results showed that alveolar clusters with smaller size and more spherical shape had lower compliance. There was a better correlation of sphericity rather than circularity with alveolar compliance. The compliance of clusters with great shape change was larger than that with relatively slight shape change. These findings suggest the contribution of lung heterogeneous expansion to lung injuries associated with mechanical ventilation.
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Affiliation(s)
- TIANYA LIU
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - YUXING WANG
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - XIAOYU LIU
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - LAN YUAN
- Beijing Key Laboratory of Rehabilitation Engineering for Elderly, National Research Center for Rehabilitation Technical Aids, Beijing 100176, P. R. China
| | - DEYU LI
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - HUITING QIAO
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
| | - YUBO FAN
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, P. R. China
- Medical and Health Analysis Center, Peking University, Beijing 100191, P. R. China
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Schittny JC. How high resolution 3-dimensional imaging changes our understanding of postnatal lung development. Histochem Cell Biol 2018; 150:677-691. [PMID: 30390117 PMCID: PMC6267404 DOI: 10.1007/s00418-018-1749-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2018] [Indexed: 12/24/2022]
Abstract
During the last 10 + years biologically and clinically significant questions about postnatal lung development could be answered due to the application of modern cutting-edge microscopic and quantitative histological techniques. These are in particular synchrotron radiation based X-ray tomographic microscopy (SRXTM), but also 3Helium Magnetic Resonance Imaging, as well as the stereological estimation of the number of alveoli and the length of the free septal edge. First, the most important new finding may be the following: alveolarization of the lung does not cease after the maturation of the alveolar microvasculature but continues until young adulthood and, even more important, maybe reactivated lifelong if needed to rescue structural damages of the lungs. Second, the pulmonary acinus represents the functional unit of the lung. Because the borders of the acini could not be detected in classical histological sections, any investigation of the acini requires 3-dimensional (imaging) methods. Based on SRXTM it was shown that in rat lungs the number of acini stays constant, meaning that their volume increases by a factor of ~ 11 after birth. The latter is very important for acinar ventilation and particle deposition.
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Affiliation(s)
- Johannes C Schittny
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012, Bern, Switzerland.
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24
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Mühlfeld C, Wrede C, Knudsen L, Buchacker T, Ochs M, Grothausmann R. Recent developments in 3-D reconstruction and stereology to study the pulmonary vasculature. Am J Physiol Lung Cell Mol Physiol 2018; 315:L173-L183. [DOI: 10.1152/ajplung.00541.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Alterations of the pulmonary vasculature are an important feature of human lung diseases such as chronic obstructive pulmonary disease, pulmonary hypertension, and bronchopulmonary dysplasia. Experimental studies to investigate the pathogenesis or a therapeutic intervention in animal models of these diseases often require robust, meaningful, and efficient morphometric data that allow for appropriate statistical testing. The gold standard for obtaining such data is design-based stereology. However, certain morphological characteristics of the pulmonary vasculature make the implementation of stereological methods challenging. For example, the alveolar capillary network functions according to the sheet flow principle, thus making unbiased length estimations impossible and requiring other strategies to obtain mechanistic morphometric data. Another example is the location of pathological changes along the branches of the vascular tree. For developmental defects like in bronchopulmonary dysplasia or for pulmonary hypertension, it is important to know whether certain segments of the vascular tree are preferentially altered. This cannot be overcome by traditional stereological methods but requires the combination of a three-dimensional data set and stereology. The present review aims at highlighting the great potential while discussing the major challenges (such as time consumption and data volume) of this combined approach. We hope to raise interest in the potential of this approach and thus stimulate solutions to overcome the existing challenges.
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Affiliation(s)
- Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Tobias Buchacker
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Roman Grothausmann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
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25
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Koo HK, Vasilescu DM, Booth S, Hsieh A, Katsamenis OL, Fishbane N, Elliott WM, Kirby M, Lackie P, Sinclair I, Warner JA, Cooper JD, Coxson HO, Paré PD, Hogg JC, Hackett TL. Small airways disease in mild and moderate chronic obstructive pulmonary disease: a cross-sectional study. THE LANCET RESPIRATORY MEDICINE 2018; 6:591-602. [PMID: 30072106 DOI: 10.1016/s2213-2600(18)30196-6] [Citation(s) in RCA: 184] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/18/2018] [Accepted: 04/30/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND The concept that small conducting airways less than 2 mm in diameter become the major site of airflow obstruction in chronic obstructive pulmonary disease (COPD) is well established in the scientific literature, and the last generation of small conducting airways, terminal bronchioles, are known to be destroyed in patients with very severe COPD. We aimed to determine whether destruction of the terminal and transitional bronchioles (the first generation of respiratory airways) occurs before, or in parallel with, emphysematous tissue destruction. METHODS In this cross-sectional analysis, we applied a novel multiresolution CT imaging protocol to tissue samples obtained using a systematic uniform sampling method to obtain representative unbiased samples of the whole lung or lobe of smokers with normal lung function (controls) and patients with mild COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 1), moderate COPD (GOLD 2), or very severe COPD (GOLD 4). Patients with GOLD 1 or GOLD 2 COPD and smokers with normal lung function had undergone lobectomy and pneumonectomy, and patients with GOLD 4 COPD had undergone lung transplantation. Lung tissue samples were used for stereological assessment of the number and morphology of terminal and transitional bronchioles, airspace size (mean linear intercept), and alveolar surface area. FINDINGS Of the 34 patients included in this study, ten were controls (smokers with normal lung function), ten patients had GOLD 1 COPD, eight had GOLD 2 COPD, and six had GOLD 4 COPD with centrilobular emphysema. The 34 lung specimens provided 262 lung samples. Compared with control smokers, the number of terminal bronchioles decreased by 40% in patients with GOLD 1 COPD (p=0·014) and 43% in patients with GOLD 2 COPD (p=0·036), the number of transitional bronchioles decreased by 56% in patients with GOLD 1 COPD (p=0·0001) and 59% in patients with GOLD 2 COPD (p=0·0001), and alveolar surface area decreased by 33% in patients with GOLD 1 COPD (p=0·019) and 45% in patients with GOLD 2 COPD (p=0·0021). These pathological changes were found to correlate with lung function decline. We also showed significant loss of terminal and transitional bronchioles in lung samples from patients with GOLD 1 or GOLD 2 COPD that had a normal alveolar surface area. Remaining small airways were found to have thickened walls and narrowed lumens, which become more obstructed with increasing COPD GOLD stage. INTERPRETATION These data show that small airways disease is a pathological feature in mild and moderate COPD. Importantly, this study emphasises that early intervention for disease modification might be required by patients with mild or moderate COPD. FUNDING Canadian Institutes of Health Research.
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Affiliation(s)
- Hyun-Kyoung Koo
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada; Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Dragoş M Vasilescu
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada
| | - Steven Booth
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada; Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Aileen Hsieh
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada
| | - Orestis L Katsamenis
- μ-VIS X-ray Imaging Centre, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - Nick Fishbane
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada
| | - W Mark Elliott
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada
| | - Miranda Kirby
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada
| | - Peter Lackie
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Ian Sinclair
- μ-VIS X-ray Imaging Centre, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - Jane A Warner
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Joel D Cooper
- Division of Thoracic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Harvey O Coxson
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada
| | - Peter D Paré
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada; Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - James C Hogg
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada; Department of Pathology, University of British Columbia, Vancouver, BC, Canada
| | - Tillie-Louise Hackett
- Centre for Heart Lung Innovation, University of British Columbia, St Paul's Hospital, Vancouver, BC, Canada; Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada.
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26
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Zhou Y, Horowitz JC, Naba A, Ambalavanan N, Atabai K, Balestrini J, Bitterman PB, Corley RA, Ding BS, Engler AJ, Hansen KC, Hagood JS, Kheradmand F, Lin QS, Neptune E, Niklason L, Ortiz LA, Parks WC, Tschumperlin DJ, White ES, Chapman HA, Thannickal VJ. Extracellular matrix in lung development, homeostasis and disease. Matrix Biol 2018. [PMID: 29524630 DOI: 10.1016/j.matbio.2018.03.005] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The lung's unique extracellular matrix (ECM), while providing structural support for cells, is critical in the regulation of developmental organogenesis, homeostasis and injury-repair responses. The ECM, via biochemical or biomechanical cues, regulates diverse cell functions, fate and phenotype. The composition and function of lung ECM become markedly deranged in pathological tissue remodeling. ECM-based therapeutics and bioengineering approaches represent promising novel strategies for regeneration/repair of the lung and treatment of chronic lung diseases. In this review, we assess the current state of lung ECM biology, including fundamental advances in ECM composition, dynamics, topography, and biomechanics; the role of the ECM in normal and aberrant lung development, adult lung diseases and autoimmunity; and ECM in the regulation of the stem cell niche. We identify opportunities to advance the field of lung ECM biology and provide a set recommendations for research priorities to advance knowledge that would inform novel approaches to the pathogenesis, diagnosis, and treatment of chronic lung diseases.
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Affiliation(s)
- Yong Zhou
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, United States.
| | - Jeffrey C Horowitz
- Division of Pulmonary and Critical Care Medicine, University of Michigan, United States.
| | - Alexandra Naba
- Department of Physiology & Biophysics, University of Illinois at Chicago, United States.
| | | | - Kamran Atabai
- Lung Biology Center, University of California, San Francisco, United States.
| | | | | | - Richard A Corley
- Systems Toxicology & Exposure Science, Pacific Northwest National Laboratory, United States.
| | - Bi-Sen Ding
- Weill Cornell Medical College, United States.
| | - Adam J Engler
- Sanford Consortium for Regenerative Medicine, University of California, San Diego, United States.
| | - Kirk C Hansen
- Biochemistry & Molecular Genetics, University of Colorado Denver, United States.
| | - James S Hagood
- Pediatric Respiratory Medicine, University of California San Diego, United States.
| | - Farrah Kheradmand
- Division of Pulmonary and Critical Care, Baylor College of Medicine, United States.
| | - Qing S Lin
- Division of Lung Diseases, National Heart, Lung, and Blood Institute, United States.
| | - Enid Neptune
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, United States.
| | - Laura Niklason
- Department of Anesthesiology, Yale University, United States.
| | - Luis A Ortiz
- Division of Environmental and Occupational Health, University of Pittsburgh, United States.
| | - William C Parks
- Department of Medicine, Cedars-Sinai Medical Center, United States.
| | - Daniel J Tschumperlin
- Department of Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, United States.
| | - Eric S White
- Division of Pulmonary and Critical Care Medicine, University of Michigan, United States.
| | - Harold A Chapman
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, United States.
| | - Victor J Thannickal
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, United States.
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Abstract
Elastase and chronic cigarette smoke exposure animal models are commonly used to study lung morphologic and functional changes associated with emphysema-like airspace enlargement in various animal species. This chapter describes the rationale for using these two models to study mechanisms of COPD pathogenesis and provides protocols for their implementation. E-cigarettes are an emerging health concern and may also contribute to lung disease. Accordingly, approaches to study e-cigarette vapors are provided. This chapter also includes methods and tools necessary to assess lung morphologic and functional changes in animals with emphysema-like airspace enlargement.
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Affiliation(s)
- Karina A Serban
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, University of Colorado Denver, Anschutz Medical Campus, Denver, CO, USA.
| | - Irina Petrache
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, University of Colorado Denver, Anschutz Medical Campus, Denver, CO, USA
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28
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Lovric G, Vogiatzis Oikonomidis I, Mokso R, Stampanoni M, Roth-Kleiner M, Schittny JC. Automated computer-assisted quantitative analysis of intact murine lungs at the alveolar scale. PLoS One 2017; 12:e0183979. [PMID: 28934236 PMCID: PMC5608210 DOI: 10.1371/journal.pone.0183979] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 08/15/2017] [Indexed: 12/13/2022] Open
Abstract
Using state-of-the-art X-ray tomographic microscopy we can image lung tissue in three dimensions in intact animals down to a micrometer precision. The structural complexity and hierarchical branching scheme of the lung at this level of details, however, renders the extraction of biologically relevant quantities particularly challenging. We have developed a methodology for a detailed description of lung inflation patterns by measuring the size and the local curvature of the parenchymal airspaces. These quantitative tools for morphological and topological analyses were applied to high-resolution murine 3D lung image data, inflated at different pressure levels under immediate post mortem conditions. We show for the first time direct indications of heterogeneous intra-lobar and inter-lobar distension patterns at the alveolar level. Furthermore, we did not find any indication that a cyclic opening-and-collapse (recruitment) of a large number of alveoli takes place.
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Affiliation(s)
- Goran Lovric
- Centre d’Imagerie BioMédicale, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
- Swiss Light Source, Paul Scherrer Institute, 5234 Villigen, Switzerland
- Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Ioannis Vogiatzis Oikonomidis
- Swiss Light Source, Paul Scherrer Institute, 5234 Villigen, Switzerland
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland
| | - Rajmund Mokso
- Max IV Laboratory, Lund University, SE-221 00 Lund, Sweden
| | - Marco Stampanoni
- Swiss Light Source, Paul Scherrer Institute, 5234 Villigen, Switzerland
- Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Matthias Roth-Kleiner
- Clinic of Neonatology, University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland
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Tanabe N, Vasilescu DM, McDonough JE, Kinose D, Suzuki M, Cooper JD, Paré PD, Hogg JC. Micro-Computed Tomography Comparison of Preterminal Bronchioles in Centrilobular and Panlobular Emphysema. Am J Respir Crit Care Med 2017; 195:630-638. [PMID: 27611890 DOI: 10.1164/rccm.201602-0278oc] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
RATIONALE Very little is known about airways that are too small to be visible on thoracic multidetector computed tomography but larger than the terminal bronchioles. OBJECTIVES To examine the structure of preterminal bronchioles located one generation proximal to terminal bronchioles in centrilobular and panlobular emphysema. METHODS Preterminal bronchioles were identified by backtracking from the terminal bronchioles, and their centerlines were established along the entire length of their lumens. Multiple cross-sectional images perpendicular to the centerline were reconstructed to evaluate the bronchiolar wall and lumen, and the alveolar attachments to the outer airway walls in relation to emphysematous destruction in 28 lung samples from six patients with centrilobular emphysema, 20 lung samples from seven patients with panlobular emphysema associated with alpha-1 antitrypsin deficiency, and 47 samples from seven control (donor) lungs. MEASUREMENTS AND MAIN RESULTS The preterminal bronchiolar length, wall volume, total volume (wall + lumen), lumen circularity, and number of alveolar attachments were reduced in both centrilobular and panlobular emphysema compared with control lungs. In contrast, thickening of the wall and narrowing of the lumen were more severe and heterogeneous in centrilobular than in panlobular emphysema. The bronchiolar lumen was narrower in the middle than at both ends, and the decreased number of alveolar attachments was associated with increased wall thickness in centrilobular emphysema. CONCLUSIONS These results provide new information about small airways pathology in centrilobular and panlobular emphysema and show that these changes affect airways that are not visible with thoracic multidetector computed tomography scans but located proximal to the terminal bronchioles in chronic obstructive pulmonary disease.
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Affiliation(s)
- Naoya Tanabe
- 1 Centre for Heart and Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dragoş M Vasilescu
- 1 Centre for Heart and Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - John E McDonough
- 1 Centre for Heart and Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.,2 Department of Clinical and Experimental Medicine, Division of Respiratory Diseases, KU Leuven-University of Leuven, Leuven, Belgium
| | - Daisuke Kinose
- 1 Centre for Heart and Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Masaru Suzuki
- 1 Centre for Heart and Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.,3 First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan; and
| | - Joel D Cooper
- 4 Division of Thoracic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Peter D Paré
- 1 Centre for Heart and Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - James C Hogg
- 1 Centre for Heart and Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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Larsson DH, Vågberg W, Yaroshenko A, Yildirim AÖ, Hertz HM. High-resolution short-exposure small-animal laboratory x-ray phase-contrast tomography. Sci Rep 2016; 6:39074. [PMID: 27958376 PMCID: PMC5153650 DOI: 10.1038/srep39074] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 11/17/2016] [Indexed: 01/06/2023] Open
Abstract
X-ray computed tomography of small animals and their organs is an essential tool in basic and preclinical biomedical research. In both phase-contrast and absorption tomography high spatial resolution and short exposure times are of key importance. However, the observable spatial resolutions and achievable exposure times are presently limited by system parameters rather than more fundamental constraints like, e.g., dose. Here we demonstrate laboratory tomography with few-ten μm spatial resolution and few-minute exposure time at an acceptable dose for small-animal imaging, both with absorption contrast and phase contrast. The method relies on a magnifying imaging scheme in combination with a high-power small-spot liquid-metal-jet electron-impact source. The tomographic imaging is demonstrated on intact mouse, phantoms and excised lungs, both healthy and with pulmonary emphysema.
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Affiliation(s)
- Daniel H. Larsson
- Department of Applied Physics, KTH Royal Institute of Technology/Albanova, 106 91 Stockholm, Sweden
| | - William Vågberg
- Department of Applied Physics, KTH Royal Institute of Technology/Albanova, 106 91 Stockholm, Sweden
| | - Andre Yaroshenko
- Physik-Department & Institut für Medizintechnik, Technische Universität München, Garching, Germany
| | - Ali Önder Yildirim
- Institute of Lung Biology and Disease, Member of the German Center for Lung Research (DZL), Helmholtz Zentrum München, Neuherberg, Germany
| | - Hans M. Hertz
- Department of Applied Physics, KTH Royal Institute of Technology/Albanova, 106 91 Stockholm, Sweden
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31
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Kizhakke Puliyakote AS, Vasilescu DM, Newell JD, Wang G, Weibel ER, Hoffman EA. Morphometric differences between central vs. surface acini in A/J mice using high-resolution micro-computed tomography. J Appl Physiol (1985) 2016; 121:115-22. [PMID: 27174924 DOI: 10.1152/japplphysiol.00317.2016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 05/06/2016] [Indexed: 11/22/2022] Open
Abstract
Through interior tomography, high-resolution microcomputed tomography (μCT) systems provide the ability to nondestructively assess the pulmonary acinus at micron and submicron resolutions. With the application of systematic uniform random sampling (SURS) principles applied to in situ fixed, intact, ex vivo lungs, we have sought to characterize morphometric differences in central vs. surface acini to better understand how well surface acini reflect global acinar geometry. Lungs from six mice (A/J strain, 15-20 wk of age) were perfusion fixed in situ and imaged using a multiresolution μCT system (Micro XCT 400, Zeiss). With the use of lower-resolution whole lung images, SURS methods were used for identification of central and surface foci for high-resolution imaging. Acinar morphometric metrics included diameters, lengths, and branching angles for each alveolar duct and total path lengths from entrance of the acinus to the terminal alveolar sacs. In addition, acinar volume, alveolar surface area, and surface area/volume ratios were assessed. A generation-based analysis demonstrated that central acini have significantly smaller branch diameters at each generation with no significant increase in branch lengths. In addition to larger-diameter alveolar ducts, surface acini had significantly increased numbers of branches and terminal alveolar sacs. The total path lengths from the acinar entrance to the terminal nodes were found to be higher in the case of surface acini. Volumes and surface areas of surface acini are greater than central acini, but there were no differences in surface/volume ratios. In conclusion, there are significant structural differences between surface and central acini in the A/J mouse.
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Affiliation(s)
- Abhilash S Kizhakke Puliyakote
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | | | - John D Newell
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | - Ge Wang
- Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia; Department of Biomedical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | | | - Eric A Hoffman
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa; Department of Medicine, University of Iowa, Iowa City, Iowa;
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Kizhakke Puliyakote AS, Vasilescu DM, Sen Sharma K, Wang G, Hoffman EA. A skeleton-tree-based approach to acinar morphometric analysis using microcomputed tomography with comparison of acini in young and old C57BL/6 mice. J Appl Physiol (1985) 2016; 120:1402-9. [PMID: 26940656 DOI: 10.1152/japplphysiol.00923.2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 02/29/2016] [Indexed: 11/22/2022] Open
Abstract
We seek to establish a method using interior tomographic techniques (Xradia MicroXCT-400) for acinar morphometric analysis using the pathway center lines from micro X-ray computed tomographic (Micro-CT) images as the road map. Through the application of these techniques, we present a method to extend the atlas of murine lungs to acinar levels and present a comparison between two age groups of the C57BL/6 strain. Lungs fixed via vascular perfusion were scanned using high-resolution Micro-CT protocols. Individual acini were segmented, and skeletonized paths to alveolar sacs from the entrance to the acinus were formed. Morphometric parameters, including branch lengths, diameters, and branching angles, were generated. Six mice each, at two age groups (∼20 and ∼90 wk of age), were studied. Additive Gaussian noise (0 mean and SD 1, 2, 5, and 10) was used to test the robustness of the analytical method. Noise-based variations were within ±6 μm for branch lengths and ±5 μm for diameters. At a noise level of 10, errors increased. Branch diameters were less susceptible to noise than lengths. There was >95% center line overlap across all noise levels. The measurements obtained using the center lines as a road map were not affected by added noise. Acini from younger mice had smaller branch diameters and lengths at all generations without significant differences in branching angles. The relative distribution of volume in the alveolar ducts was similar across both age groups. The method has been demonstrated to be repeatable and robust to image noise and provides a new, nondestructive technique to assess and compare acinar morphometry quantitatively.
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Affiliation(s)
- Abhilash S Kizhakke Puliyakote
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | | | - Kriti Sen Sharma
- Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia; and
| | - Ge Wang
- Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia; and Department of Biomedical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - Eric A Hoffman
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa; Department of Medicine, University of Iowa, Iowa City, Iowa;
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Mühlfeld C, Hegermann J, Wrede C, Ochs M. A review of recent developments and applications of morphometry/stereology in lung research. Am J Physiol Lung Cell Mol Physiol 2015; 309:L526-36. [DOI: 10.1152/ajplung.00047.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 07/09/2015] [Indexed: 11/22/2022] Open
Abstract
Design-based stereology is the gold standard of morphometry in lung research. Here, we analyze the current use of morphometric and stereological methods in lung research and provide an overview on recent methodological developments and biological observations made by the use of stereology. Based on this analysis we hope to provide useful recommendations for a good stereological practice to further the use of advanced and unbiased stereological methods.
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Affiliation(s)
- Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany; and
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
| | - Jan Hegermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany; and
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
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Scott AE, Vasilescu DM, Seal KAD, Keyes SD, Mavrogordato MN, Hogg JC, Sinclair I, Warner JA, Hackett TL, Lackie PM. Three dimensional imaging of paraffin embedded human lung tissue samples by micro-computed tomography. PLoS One 2015; 10:e0126230. [PMID: 26030902 PMCID: PMC4452358 DOI: 10.1371/journal.pone.0126230] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 03/30/2015] [Indexed: 11/21/2022] Open
Abstract
Background Understanding the three-dimensional (3-D) micro-architecture of lung tissue can provide insights into the pathology of lung disease. Micro computed tomography (µCT) has previously been used to elucidate lung 3D histology and morphometry in fixed samples that have been stained with contrast agents or air inflated and dried. However, non-destructive microstructural 3D imaging of formalin-fixed paraffin embedded (FFPE) tissues would facilitate retrospective analysis of extensive tissue archives of lung FFPE lung samples with linked clinical data. Methods FFPE human lung tissue samples (n = 4) were scanned using a Nikon metrology µCT scanner. Semi-automatic techniques were used to segment the 3D structure of airways and blood vessels. Airspace size (mean linear intercept, Lm) was measured on µCT images and on matched histological sections from the same FFPE samples imaged by light microscopy to validate µCT imaging. Results The µCT imaging protocol provided contrast between tissue and paraffin in FFPE samples (15mm x 7mm). Resolution (voxel size 6.7 µm) in the reconstructed images was sufficient for semi-automatic image segmentation of airways and blood vessels as well as quantitative airspace analysis. The scans were also used to scout for regions of interest, enabling time-efficient preparation of conventional histological sections. The Lm measurements from µCT images were not significantly different to those from matched histological sections. Conclusion We demonstrated how non-destructive imaging of routinely prepared FFPE samples by laboratory µCT can be used to visualize and assess the 3D morphology of the lung including by morphometric analysis.
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Affiliation(s)
- Anna E. Scott
- μ-VIS Centre, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
| | - Dragos M. Vasilescu
- James Hogg Research Centre, University of British Columbia, Vancouver, Canada
| | | | - Samuel D. Keyes
- μ-VIS Centre, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
| | - Mark N. Mavrogordato
- μ-VIS Centre, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
| | - James C. Hogg
- James Hogg Research Centre, University of British Columbia, Vancouver, Canada
| | - Ian Sinclair
- μ-VIS Centre, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
| | - Jane A. Warner
- Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
| | - Tillie-Louise Hackett
- James Hogg Research Centre, University of British Columbia, Vancouver, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Peter M. Lackie
- Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom
- * E-mail:
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35
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Mayhew T. Morphomics: An integral part of systems biology of the human placenta. Placenta 2015; 36:329-40. [DOI: 10.1016/j.placenta.2015.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/05/2015] [Accepted: 01/07/2015] [Indexed: 01/03/2023]
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36
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Mayhew TM, Lucocq JM. From gross anatomy to the nanomorphome: stereological tools provide a paradigm for advancing research in quantitative morphomics. J Anat 2015; 226:309-21. [PMID: 25753334 DOI: 10.1111/joa.12287] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2015] [Indexed: 01/08/2023] Open
Abstract
The terms morphome and morphomics are not new but, recently, a group of morphologists and cell biologists has given them clear definitions and emphasised their integral importance in systems biology. By analogy to other '-omes', the morphome refers to the distribution of matter within 3-dimensional (3D) space. It equates to the totality of morphological features within a biological system (virus, single cell, multicellular organism or populations thereof) and morphomics is the systematic study of those structures. Morphomics research has the potential to generate 'big data' because it includes all imaging techniques at all levels of achievable resolution and all structural scales from gross anatomy and medical imaging, via optical and electron microscopy, to molecular characterisation. As with other '-omics', quantification is an important part of morphomics and, because biological systems exist and operate in 3D space, precise descriptions of form, content and spatial relationships require the quantification of structure in 3D. Revealing and quantifying structural detail inside the specimen is achieved currently in two main ways: (i) by some form of reconstruction from serial physical or tomographic slices or (ii) by using randomly-sampled sections and simple test probes (points, lines, areas, volumes) to derive stereological estimates of global and/or individual quantities. The latter include volumes, surfaces, lengths and numbers of interesting features and spatial relationships between them. This article emphasises the value of stereological design, sampling principles and estimation tools as a template for combining with alternative imaging techniques to tackle the 'big data' issue and advance knowledge and understanding of the morphome. The combination of stereology, TEM and immunogold cytochemistry provides a practical illustration of how this has been achieved in the sub-field of nanomorphomics. Applying these quantitative tools/techniques in a carefully managed study design offers us a deeper appreciation of the spatiotemporal relationships between the genome, metabolome and morphome which are integral to systems biology.
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Affiliation(s)
- Terry M Mayhew
- School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK; School of Medicine, University of St Andrews, St Andrews, UK
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Chang S, Kwon N, Kim J, Kohmura Y, Ishikawa T, Rhee CK, Je JH, Tsuda A. Synchrotron X-ray imaging of pulmonary alveoli in respiration in live intact mice. Sci Rep 2015; 5:8760. [PMID: 25737245 PMCID: PMC4348649 DOI: 10.1038/srep08760] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/03/2015] [Indexed: 12/29/2022] Open
Abstract
Despite nearly a half century of studies, it has not been fully understood how pulmonary alveoli, the elementary gas exchange units in mammalian lungs, inflate and deflate during respiration. Understanding alveolar dynamics is crucial for treating patients with pulmonary diseases. In-vivo, real-time visualization of the alveoli during respiration has been hampered by active lung movement. Previous studies have been therefore limited to alveoli at lung apices or subpleural alveoli under open thorax conditions. Here we report direct and real-time visualization of alveoli of live intact mice during respiration using tracking X-ray microscopy. Our studies, for the first time, determine the alveolar size of normal mice in respiration without positive end expiratory pressure as 58 ± 14 (mean ± s.d.) μm on average, accurately measured in the lung bases as well as the apices. Individual alveoli of normal lungs clearly show heterogeneous inflation from zero to ~25% (6.7 ± 4.7% (mean ± s.d.)) in size. The degree of inflation is higher in the lung bases (8.7 ± 4.3% (mean ± s.d.)) than in the apices (5.7 ± 3.2% (mean ± s.d.)). The fraction of the total tidal volume allocated for alveolar inflation is 34 ± 3.8% (mean ± s.e.m). This study contributes to the better understanding of alveolar dynamics and helps to develop potential treatment options for pulmonary diseases.
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Affiliation(s)
- Soeun Chang
- 1] X-ray Imaging Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea [2] Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea
| | - Namseop Kwon
- 1] X-ray Imaging Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea [2] School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea
| | - Jinkyung Kim
- X-ray Imaging Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea
| | - Yoshiki Kohmura
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo, Hyogo, 679-5198, Japan
| | - Tetsuya Ishikawa
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo, Hyogo, 679-5198, Japan
| | - Chin Kook Rhee
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, 505 Banpo-dong, Seocho-Gu, Seoul, 137-701, Korea
| | - Jung Ho Je
- 1] X-ray Imaging Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea [2] Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang, 790-784, Korea [3] RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo, Hyogo, 679-5198, Japan
| | - Akira Tsuda
- Harvard School of Public Health, Boston, Massachusetts, USA
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Suki B, Parameswaran H. Computational modeling helps uncover mechanisms related to the progression of emphysema. ACTA ACUST UNITED AC 2015; 70:4245-4249. [PMID: 24904681 DOI: 10.1016/j.ddmod.2014.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Emphysema is a progressive disease characterized by deterioration of alveolar structure and decline in lung function. While morphometric and molecular biology studies have not fully uncovered the underlying mechanisms, they have produced data to advance computational modeling. In this review, we discuss examples in which modeling has led to novel insight into mechanisms related to disease progression. Finally, we propose a general scheme of multiscale modeling approach that could help unravel the progressive nature of emphysema and provide patient specific mechanisms perhaps suitable for use in treatment therapies.
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Affiliation(s)
- Béla Suki
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
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40
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Milne S, King GG. Advanced imaging in COPD: insights into pulmonary pathophysiology. J Thorac Dis 2014; 6:1570-85. [PMID: 25478198 DOI: 10.3978/j.issn.2072-1439.2014.11.30] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 11/10/2014] [Indexed: 12/31/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) involves a complex interaction of structural and functional abnormalities. The two have long been studied in isolation. However, advanced imaging techniques allow us to simultaneously assess pathological processes and their physiological consequences. This review gives a comprehensive account of the various advanced imaging modalities used to study COPD, including computed tomography (CT), magnetic resonance imaging (MRI), and the nuclear medicine techniques positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Some more recent developments in imaging technology, including micro-CT, synchrotron imaging, optical coherence tomography (OCT) and electrical impedance tomography (EIT), are also described. The authors identify the pathophysiological insights gained from these techniques, and speculate on the future role of advanced imaging in both clinical and research settings.
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Affiliation(s)
- Stephen Milne
- 1 The Woolcock Institute of Medical Research, Glebe, Sydney NSW 2037, Australia ; 2 Northern Clinical School, University of Sydney, NSW 2006, Australia ; 3 Northern and Central Clinical Schools, University of Sydney, NSW 2006, Australia ; 4 Department of Respiratory Medicine, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
| | - Gregory G King
- 1 The Woolcock Institute of Medical Research, Glebe, Sydney NSW 2037, Australia ; 2 Northern Clinical School, University of Sydney, NSW 2006, Australia ; 3 Northern and Central Clinical Schools, University of Sydney, NSW 2006, Australia ; 4 Department of Respiratory Medicine, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
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Yoder BA, Coalson JJ. Animal models of bronchopulmonary dysplasia. The preterm baboon models. Am J Physiol Lung Cell Mol Physiol 2014; 307:L970-7. [PMID: 25281639 DOI: 10.1152/ajplung.00171.2014] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Much of the progress in improved neonatal care, particularly management of underdeveloped preterm lungs, has been aided by investigations of multiple animal models, including the neonatal baboon (Papio species). In this article we highlight how the preterm baboon model at both 140 and 125 days gestation (term equivalent 185 days) has advanced our understanding and management of the immature human infant with neonatal lung disease. Not only is the 125-day baboon model extremely relevant to the condition of bronchopulmonary dysplasia but there are also critical neurodevelopmental and other end-organ pathological features associated with this model not fully discussed in this limited forum. We also describe efforts to incorporate perinatal infection into these preterm models, both fetal and neonatal, and particularly associated with Ureaplasma/Mycoplasma organisms. Efforts to rekindle the preterm primate model for future evaluations of therapies such as stem cell replacement, early lung recruitment interventions coupled with noninvasive surfactant and high-frequency nasal ventilation, and surfactant therapy coupled with antioxidant or anti-inflammatory medications, to name a few, should be undertaken.
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Affiliation(s)
- Bradley A Yoder
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Jacqueline J Coalson
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
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Thane K, Ingenito EP, Hoffman AM. Lung regeneration and translational implications of the postpneumonectomy model. Transl Res 2014; 163:363-76. [PMID: 24316173 DOI: 10.1016/j.trsl.2013.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/30/2013] [Accepted: 11/18/2013] [Indexed: 10/26/2022]
Abstract
Lung regeneration research is yielding data with increasing translational value. The classical models of lung development, postnatal alveolarization, and postpneumonectomy alveolarization have contributed to a broader understanding of the cellular participants including stem-progenitor cells, cell-cell signaling pathways, and the roles of mechanical deformation and other physiologic factors that have the potential to be modulated in human and animal patients. Although recent information is available describing the lineage fate of lung fibroblasts, genetic fate mapping, and clonal studies are lacking in the study of lung regeneration and deserve further examination. In addition to increasing knowledge concerning classical alveolarization (postnatal, postpneumonectomy), there is increasing evidence for remodeling of the adult lung after partial pneumonectomy. Though limited in scope, compelling data have emerged describing restoration of lung tissue mass in the adult human and in large animal models. The basis for this long-term adaptation to pneumonectomy is poorly understood, but investigations into mechanisms of lung regeneration in older animals that have lost their capacity for rapid re-alveolarization are warranted, as there would be great translational value in modulating these mechanisms. In addition, quantitative morphometric analysis has progressed in conjunction with developments in advanced imaging, which allow for longitudinal and nonterminal evaluation of pulmonary regenerative responses in animals and humans. This review focuses on the cellular and molecular events that have been observed in animals and humans after pneumonectomy because this model is closest to classical regeneration in other mammalian systems and has revealed several new fronts of translational research that deserve consideration.
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Affiliation(s)
- Kristen Thane
- Department of Clinical Sciences, Regenerative Medicine Laboratory, Tufts University Cummings School of Veterinary Medicine, North Grafton, Mass
| | - Edward P Ingenito
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brigham and Women's Hospital, Boston, Mass
| | - Andrew M Hoffman
- Department of Clinical Sciences, Regenerative Medicine Laboratory, Tufts University Cummings School of Veterinary Medicine, North Grafton, Mass.
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Ochs M. Estimating structural alterations in animal models of lung emphysema. Is there a gold standard? Ann Anat 2013; 196:26-33. [PMID: 24268708 DOI: 10.1016/j.aanat.2013.10.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 10/07/2013] [Accepted: 10/12/2013] [Indexed: 01/08/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases. The major component of COPD, which affects the gas-exchanging parenchyma of the lung, emphysema, is characterized by destruction of alveolar septae leading to loss of functional surface, loss of alveoli and enlargement of remaining distal airspaces. These microstructural alterations can be modeled in animals and can be measured using stereological methods applied to imaging datasets. Many animal models of emphysema exist, but most of them are insufficiently characterized with respect to the underlying nature (e.g. destructive or developmental) and the degree of the structural alterations. The most popular parameter for assessment of emphysematous alterations, mean linear intercept length, has severe limitations. It can, therefore, not be recommended. Better design-based stereological alternatives exist but are less often applied, such as total volumes of parenchymal compartments (alveolar airspace, alveolar duct airspace, alveolar septum), total alveolar surface area, total alveolar number and mean alveolar size and its size variation. A prerequisite is the use of appropriate fixation, sampling, and specimen processing protocols. This article reviews the challenges of stereologic assessment of emphysematous alterations in the lung and illustrates possible strategies.
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Affiliation(s)
- Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany.
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Sen Sharma K, Holzner C, Vasilescu DM, Jin X, Narayanan S, Agah M, Hoffman EA, Yu H, Wang G. Scout-view assisted interior micro-CT. Phys Med Biol 2013; 58:4297-314. [PMID: 23732478 PMCID: PMC3732817 DOI: 10.1088/0031-9155/58/12/4297] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Micro computed tomography (micro-CT) is a widely-used imaging technique. A challenge of micro-CT is to quantitatively reconstruct a sample larger than the field-of-view (FOV) of the detector. This scenario is characterized by truncated projections and associated image artifacts. However, for such truncated scans, a low resolution scout scan with an increased FOV is frequently acquired so as to position the sample properly. This study shows that the otherwise discarded scout scans can provide sufficient additional information to uniquely and stably reconstruct the interior region of interest. Two interior reconstruction methods are designed to utilize the multi-resolution data without significant computational overhead. While most previous studies used numerically truncated global projections as interior data, this study uses truly hybrid scans where global and interior scans were carried out at different resolutions. Additionally, owing to the lack of standard interior micro-CT phantoms, we designed and fabricated novel interior micro-CT phantoms for this study to provide means of validation for our algorithms. Finally, two characteristic samples from separate studies were scanned to show the effect of our reconstructions. The presented methods show significant improvements over existing reconstruction algorithms.
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Affiliation(s)
- Kriti Sen Sharma
- Dept. of Elec. & Comp. Eng., Virginia Tech, Blacksburg, VA 24061, USA
| | | | - Dragoş M. Vasilescu
- UBC James Hogg Research Centre at the Heart & Lung Institute, St Paul’s Hospital, Vancouver, B.C., V6Z 1Y6, Canada
| | - Xin Jin
- Dept. of Eng. Phys., Tsinghua Univ., Beijing 100084, China
| | - Shree Narayanan
- Dept. of Elec. & Comp. Eng., Virginia Tech, Blacksburg, VA 24061, USA
| | - Masoud Agah
- Dept. of Elec. & Comp. Eng., Virginia Tech, Blacksburg, VA 24061, USA
| | | | - Hengyong Yu
- Biomedical Imaging Division, VT-WFU School of Biomedical Eng. & Sciences, Wake Forest Univ. Health Sciences, Winston-Salem, NC 27157, USA
| | - Ge Wang
- Biomedical Imaging Center, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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Sera T, Yokota H, Tanaka G, Uesugi K, Yagi N, Schroter RC. Murine pulmonary acinar mechanics during quasi-static inflation using synchrotron refraction-enhanced computed tomography. J Appl Physiol (1985) 2013; 115:219-28. [PMID: 23661619 DOI: 10.1152/japplphysiol.01105.2012] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We visualized pulmonary acini in the core regions of the mouse lung in situ using synchrotron refraction-enhanced computed tomography (CT) and evaluated their kinematics during quasi-static inflation. This CT system (with a cube voxel of 2.8 μm) allows excellent visualization of not just the conducting airways, but also the alveolar ducts and sacs, and tracking of the acinar shape and its deformation during inflation. The kinematics of individual alveoli and alveolar clusters with a group of terminal alveoli is influenced not only by the connecting alveolar duct and alveoli, but also by the neighboring structures. Acinar volume was not a linear function of lung volume. The alveolar duct diameter changed dramatically during inflation at low pressures and remained relatively constant above an airway pressure of ∼8 cmH2O during inflation. The ratio of acinar surface area to acinar volume indicates that acinar distension during low-pressure inflation differed from that during inflation over a higher pressure range; in particular, acinar deformation was accordion-like during low-pressure inflation. These results indicated that the alveoli and duct expand differently as total acinar volume increases and that the alveolar duct may expand predominantly during low-pressure inflation. Our findings suggest that acinar deformation in the core regions of the lung is complex and heterogeneous.
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Affiliation(s)
- Toshihiro Sera
- Center for Advanced Medical Engineering and Informatics, Osaka University, Osaka, Japan.
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Kumar H, Vasilescu DM, Yin Y, Hoffman EA, Tawhai MH, Lin CL. Multiscale imaging and registration-driven model for pulmonary acinar mechanics in the mouse. J Appl Physiol (1985) 2013; 114:971-8. [PMID: 23412896 DOI: 10.1152/japplphysiol.01136.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A registration-based multiscale method to obtain a deforming geometric model of mouse acinus is presented. An intact mouse lung was fixed by means of vascular perfusion at a hydrostatic inflation pressure of 20 cmH(2)O. Microcomputed tomography (μCT) scans were obtained at multiple resolutions. Substructural morphometric analysis of a complete acinus was performed by computing a surface-to-volume (S/V) ratio directly from the 3D reconstruction of the acinar geometry. A geometric similarity is observed to exist in the acinus where S/V is approximately preserved anywhere in the model. Using multiscale registration, the shape of the acinus at an elevated inflation pressure of 25 cmH(2)O is estimated. Changes in the alveolar geometry suggest that the deformation within the acinus is not isotropic. In particular, the expansion of the acinus (from 20 to 25 cmH(2)O) is accompanied by an increase in both surface area and volume in such a way that the S/V ratio is not significantly altered. The developed method forms a useful tool in registration-driven fluid and solid mechanics studies as displacement of the alveolar wall becomes available in a discrete sense.
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Affiliation(s)
- Haribalan Kumar
- Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242-1527, USA
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