Requirements and limitations of imaging airway smooth muscle throughout the lung in vivo

Michael J Hackmann; John G Elliot; Francis H Y Green; Alvenia Cairncross; Barry Cense; Robert A McLaughlin; David Langton; Alan L James; Peter B Noble; Graham M Donovan

doi:10.1016/j.resp.2022.103884

Requirements and limitations of imaging airway smooth muscle throughout the lung in vivo

Respir Physiol Neurobiol. 2022 Jul:301:103884. doi: 10.1016/j.resp.2022.103884. Epub 2022 Mar 15.

Authors

Affiliations

¹ School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia; School of Engineering, University of Western Australia, Perth, Western Australia, Australia. Electronic address: michael.hackmann@research.uwa.edu.au.
² School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia; West Australian Sleep Disorders Research Institute, Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.
³ Department of Pathology and Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
⁴ School of Human Sciences, The University of Western Australia, Crawley, Western Australia, Australia.
⁵ School of Engineering, University of Western Australia, Perth, Western Australia, Australia; Department of Mechanical Engineering, Yonsei University, Seoul, South-Korea.
⁶ School of Engineering, University of Western Australia, Perth, Western Australia, Australia; Australian Research Council Centre of Excellence for Nanoscale Biophotonics, 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.
⁷ Faculty of Medicine, Nursing and Allied Health, Monash University, Melbourne, Victoria, Australia.
⁸ West Australian Sleep Disorders Research Institute, Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Medical School, The University of Western Australia, Nedlands, Western Australia, Australia.
⁹ Department of Mathematics, University of Auckland, Auckland, New Zealand.

PMID: 35301143
DOI: 10.1016/j.resp.2022.103884

Abstract

Clinical visualization and quantification of the amount and distribution of airway smooth muscle (ASM) in the lungs of individuals with asthma has major implications for our understanding of airway wall remodeling as well as treatments targeted at the ASM. This paper theoretically investigates the feasibility of quantifying airway wall thickness (focusing on the ASM) throughout the lung in vivo by means of bronchoscopic polarization-sensitive optical coherence tomography (PS-OCT). Using extensive human biobank data from subjects with and without asthma in conjunction with a mathematical model of airway compliance, we define constraints that airways of various sizes pose to any endoscopic imaging technique and how this is impacted by physiologically relevant processes such as constriction, inflation and deflation. We identify critical PS-OCT system parameters and pinpoint parts of the airway tree that are conducive to successful quantification of ASM. We further quantify the impact of breathing and ASM contraction on the measurement error and recommend strategies for standardization and normalization.

Keywords: Airway smooth muscle; Asthma; Bronchoscopy; Imaging; Polarization-sensitive optical coherence tomography; Remodeling.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Airway Remodeling
Asthma* / diagnostic imaging
Humans
Lung / diagnostic imaging
Muscle Contraction / physiology
Muscle, Smooth* / diagnostic imaging