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Hackmann MJ, Cairncross A, Elliot JG, Mulrennan S, Nilsen K, Thompson BR, Li Q, Karnowski K, Sampson DD, McLaughlin RA, Cense B, James AL, Noble PB. Quantification of smooth muscle in human airways by polarization-sensitive optical coherence tomography requires correction for perichondrium. Am J Physiol Lung Cell Mol Physiol 2024; 326:L393-L408. [PMID: 38261720 DOI: 10.1152/ajplung.00254.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 12/05/2023] [Accepted: 01/12/2024] [Indexed: 01/25/2024] Open
Abstract
Quantifying airway smooth muscle (ASM) in patients with asthma raises the possibility of improved and personalized disease management. Endobronchial polarization-sensitive optical coherence tomography (PS-OCT) is a promising quantitative imaging approach that is in the early stages of clinical translation. To date, only animal tissues have been used to assess the accuracy of PS-OCT to quantify absolute (rather than relative) ASM in cross sections with directly matched histological cross sections as validation. We report the use of whole fresh human and pig airways to perform a detailed side-by-side qualitative and quantitative validation of PS-OCT against gold-standard histology. We matched and quantified 120 sections from five human and seven pig (small and large) airways and linked PS-OCT signatures of ASM to the tissue structural appearance in histology. Notably, we found that human cartilage perichondrium can share with ASM the properties of birefringence and circumferential alignment of fibers, making it a significant confounder for ASM detection. Measurements not corrected for perichondrium overestimated ASM content several-fold (P < 0.001, paired t test). After careful exclusion of perichondrium, we found a strong positive correlation (r = 0.96, P < 0.00001) of ASM area measured by PS-OCT and histology, supporting the method's application in human subjects. Matching human histology further indicated that PS-OCT allows conclusions on the intralayer composition and in turn potential contractile capacity of ASM bands. Together these results form a reliable basis for future clinical studies.NEW & NOTEWORTHY Polarization-sensitive optical coherence tomography (PS-OCT) may facilitate in vivo measurement of airway smooth muscle (ASM). We present a quantitative validation correlating absolute ASM area from PS-OCT to directly matched histological cross sections using human tissue. A major confounder for ASM quantification was observed and resolved: fibrous perichondrium surrounding hyaline cartilage in human airways presents a PS-OCT signature similar to ASM for birefringence and optic axis orientation. Findings impact the development of automated methods for ASM segmentation.
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Affiliation(s)
- Michael J Hackmann
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Electrical, Electronic, and Computer Engineering, The University of Western Australia, Crawley, Western Australia, Australia
| | - Alvenia Cairncross
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Western Australia, Australia
| | - John G Elliot
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Western Australia, Australia
| | - Siobhain Mulrennan
- Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
- Institute of Respiratory Health, The University of Western Australia, Crawley, Western Australia, Australia
- Medical School, The University of Western Australia, Crawley, Western Australia, Australia
| | - Kris Nilsen
- Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Bruce R Thompson
- Melbourne School of Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Qingyun Li
- Department of Electrical, Electronic, and Computer Engineering, The University of Western Australia, Crawley, Western Australia, Australia
| | - Karol Karnowski
- Department of Electrical, Electronic, and Computer Engineering, The University of Western Australia, Crawley, Western Australia, Australia
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - David D Sampson
- School of Computer Science and Electronic Engineering, University of Surrey, Guildford, United Kingdom
| | - Robert A McLaughlin
- Department of Electrical, Electronic, and Computer Engineering, The University of Western Australia, Crawley, Western Australia, Australia
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- Institute for Photonics and Advanced Sensing, The University of Adelaide, Adelaide, South Australia, Australia
| | - Barry Cense
- Department of Electrical, Electronic, and Computer Engineering, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Mechanical Engineering, Yonsei University, Seoul, South Korea
| | - Alan L James
- Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Western Australia, Australia
- Medical School, The University of Western Australia, Crawley, Western Australia, Australia
| | - Peter B Noble
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
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Donovan GM. Which airways should we treat? Structure-function relationships and estimation of the singular input modes from the forward model alone. Math Med Biol 2023; 40:291-307. [PMID: 37775271 DOI: 10.1093/imammb/dqad006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 09/10/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023]
Abstract
Structure-function relationships occur throughout the sciences. Motivated by optimization of such systems, we develop a framework for estimating the input modes from the singular value decomposition from the action of the forward operator alone. These can then be used to determine the input (structure) changes, which induce the largest output (function) changes. The accuracy of the estimate is determined by reference to the method of snapshots. The proposed method is demonstrated on several example problems, and finally used to approximate the optimal airway treatment set for a problem in respiratory physiology.
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Affiliation(s)
- Graham M Donovan
- Department of Mathematics, The University of Auckland, Private Bag 92019, 1142, Auckland, New Zealand
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Donovan GM, Wang KCW, Elliot JG, James AL, Noble PB. Quantifying airway remodelling for research or clinical purposes: How should we normalize for airway size? Respirology 2023; 28:223-225. [PMID: 36691759 DOI: 10.1111/resp.14454] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/08/2023] [Indexed: 01/25/2023]
Affiliation(s)
- Graham M Donovan
- Department of Mathematics, University of Auckland, Auckland, New Zealand
| | - Kimberley C W Wang
- Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia, Australia.,School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - John G Elliot
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia.,Department of Pulmonary Physiology and Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Alan L James
- Department of Pulmonary Physiology and Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.,Medical School, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Peter B Noble
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
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Donovan GM, Noble PB, Langton D. Therapeutic response to bronchial thermoplasty: toward feasibility of patient selection based on modeling predictions. J Appl Physiol (1985) 2022; 133:1341-1348. [PMID: 36356255 DOI: 10.1152/japplphysiol.00493.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bronchial thermoplasty (BT) is a treatment for moderate-to-severe asthma in which the airway smooth muscle layer is targeted directly using thermal ablation. Although it has been shown to be safe and effective in long-term follow-up, questions remain about its mechanism of action, patient selection, and optimization of protocol based on structural phenotype. Using a cohort of 20 subjects who underwent thermoplasty and assessment by computed tomography (CT), we demonstrate that response to BT can be feasibly predicted based on pretreatment airway dimensions that inform a subject-specific computational model. Analysis revealed the need for CT assessment at total lung capacity, rather than functional residual capacity, which was less sensitive to the effects of BT. Final model predictions compared favorably with observed outcomes in terms of airway caliber and asthma control, suggesting that this approach could form the basis of improved clinical practice.NEW & NOTEWORTHY Bronchial thermoplasty is a treatment for asthma that targets the airway smooth muscle directly. We demonstrate the feasibility and constraints of predicting patient-specific response to thermoplasty using a computational model informed by pretreatment CT scans at different lung volumes. Predictions are compared with functional outcomes and posttreatment CT scans. This has the potential to form the basis for improved clinical practice.
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Affiliation(s)
- G M Donovan
- Department of Mathematics, The University of Auckland, Auckland, New Zealand
| | - P B Noble
- School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - D Langton
- Faculty of Medicine, Nursing and Allied Health, Monash University, Melbourne, Victoria, Australia
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