Airway wall thickness and airflow limitations in asthma assessed in quantitative computed tomography

Abstract

Background: Asthma is a frequent chronic disease of the airways. In spite of the fact that symptoms of asthma are well known, the pathogenesis has not yet been fully understood. Quantitative computed tomography (qCT) of the lung allows for the measurment of a set of parameters. The aim of this study was to evaluate the usefulness of quantitative computed tomography in the assessment of airway wall thickness in asthma. Methods: The prospective study was performed on a group of 83 patients with well-defined, long-term asthma between 2016 and 2018. The control group was composed of 30 healthy volunteers. All examined subjects were non-smokers. All computed tomography (CT) studies were performed using a 128 multi-slice CT scanner with no contrast, following a chest scanning protocol in the supine position, at full inspiration and breath-holds. Results: Quantitative bronchial tree measurements were obtained from the third up to the ninth generation of the posterior basal bronchi (B10) of the right lung in a blinded fashion. The value of the wall thickness in patients with asthma was significantly higher in all measured generations of the bronchial tree (third to ninth generation). The lumen area and the inner diameter significantly correlated with the lung function tests and were substantially smaller in the examined group from the seventh to the ninth generation of the bronchi ( p < 0.05). Conclusions: We conclude that airway remodelling occurs in most patients with long-term asthma and is associated mainly with the medium and small airways. Imaging techniques, especially qCT can be useful in the diagnosis and management of asthma. The reviews of this paper are available via the supplemental material section.

Similarities in Quantitative Computed Tomography Imaging of the Lung in Severe Asthma with Persistent Airflow Limitation and Chronic Obstructive Pulmonary Disease

“…The full methodology of CT scanning, lung function testing, and statistical analysis were described in the associated publication: Patyk M. et al (2020) [ 20 ].…”

Structure and function of small airways in asthma patients revisited

“…Thanks to the development of high-resolution CT scanners and advanced reconstruction techniques it is now possible to visualise airways in the range of 1 mm in diameter using low-dose protocols. CT images acquired during a breath hold at full inspiration can provide detailed information on airway generation and airway wall dimensions (figure 3) [138]. In operated patients with COPD it was shown that airway size measured by pre-operative CT correlated to airway size as measured histologically [139].…”

“…In asthma it was shown that the airway walls, as measured on CT, were thicker compared to healthy subjects. Furthermore, it was shown that increased airway wall thickness observed on CT was related to lower forced expiratory volume in 1 s and higher risk of exacerbations [138,140]. Static CT images acquired during expiration can show regions of low attenuation that are thought to reflect SAD (figure 2).…”

Airway remodeling assessed by quantitative computed tomography at various stages of asthma severity defined according to Global Initiative for Asthma report: a single-center study

“…More details of the computed tomography scanning protocol, measuring of the bronchial tree features are described in Patyk et al (2020) study [12].…”

“…The influence of airway remodeling on lung function is postulated, and the relationship is still under investigation [11]. In the previous study significant increase of airway thickness in patients with asthma comparing to healthy subjects was revealed [12].…”