Structural and functional changes in COPD: What we have learned from imaging

Abstract

Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality worldwide. It is a heterogeneous disease involving different components of the lung to varying extents. Developments in medical imaging and image analysis techniques provide new insights in the assessment of the structural and functional changes of the disease. This article reviews the leading imaging techniques: CT and MRI of the lung in research settings and clinical routine. Both visual and quantitative methods are reviewed, emphasizing their relevance to patient phenotyping and outcome prediction. MORPHOLOGICAL IMAGINGChest CT scans are of great interest in the non-invasive investigation of structural abnormalities involving the separate compartments of the lung, 3,4,[20][21][22][23] allowing for discrimination of different subtypes of COPD patients. 4,15,17,22 Airways Visualization of the bronchial tree with CT images is feasible down to the sixth or seventh generation. 24 Bronchiectasis, chronic bronchitis and mucus plugging are part of the pathological features of the disease. Detection of these airway changes and their regional distribution using CT helps clinicians to better follow-up COPD patients. 25,26 It remains unclear whether bronchiectasis may define the specific phenotype of COPD, although studies have demonstrated more severe exacerbations in patients exhibiting bronchiectasis. 27

Genome-Wide Association Study of Airway Wall Thickening in a Korean Chronic Obstructive Pulmonary Disease Cohort

“…The combination of quantitative parameters offered by these tools enables better analysis of COPD phenotypes and prediction of outcomes. Therefore, in addition to diagnosis, these quantitative measurements allow for the staging of disease severity and phenotyping of patients [ 23 ]. In chest CT scan phenotypes, the estimated heritability of both FEV1 and FEV1/FVC is close to 25%, while the heritability of COPD status was estimated to be 37.7% in non-Hispanic whites and African Americans [ 24 ].…”

Epilogue to contemporary perspectives in COPD: New Horizons

“…New diagnostic techniques and imaging modalities are adding precision and early diagnostic potential. 4 At the same time, the role of non-pharmacological therapies has evolved to be a great deal more than smoking cessation, vaccination and pulmonary rehabilitation. Pharmacological interventions for COPD are now approached with a far more nuanced assessment of patients, based on the severity of airflow limitation, and then independently, symptom and exacerbation burden.…”

“…Worldwide estimates of COPD were based on variable data collection methods, self‐report and doctor diagnosis which had a high degree of unreliability, and began to be addressed by the first major effort to assess global COPD prevalence 2 . It should be reassuring to reflect on what has been achieved since then, specifically in the development of new pharmacotherapies, 3 the application of sophisticated imaging techniques, 4 the widespread use of computed tomography scanning to better understand early disease, 5 the development of widely used patient‐reported outcome measures in clinical trials, 6,7 epidemiology and database analyses 8–10 and practical clinical tools to assess symptom burden and patient progress in the clinic 11 . A multitude of clinical trials have been undertaken focused on exacerbations, mortality and the most troubling symptoms of the disease 12 .…”

“…New treatment innovations, particularly interventional pulmonology, lung volume reduction surgery and lung transplantation, have evolved over this period to become an established part of the management of severe COPD. New diagnostic techniques and imaging modalities are adding precision and early diagnostic potential 4 …”

Computed tomography‐based artificial intelligence in lung disease—Chronic obstructive pulmonary disease

“…5 As COPD progresses, it leads to structural changes within the lungs, including airway wall thickening, bronchial mucus hypersecretion, loss of elasticity, and the destruction of alveoli. 6 Therefore, objective imaging biomarkers are essential in addressing these challenges. Computed tomography (CT) scans offer high-resolution insights into the structural alterations in the lungs, allowing for revealing characteristic signs of COPD, differentiating different phenotypes of COPD, and assessing the degree of structural damage.…”