Abstract
ObjectivesTo investigate the association between emphysema heterogeneity in spatial distribution, pulmonary function and disease severity.Methods and MaterialsWe ascertained a dataset of anonymized Computed Tomography (CT) examinations acquired on 565 participants in a COPD study. Subjects with chronic bronchitis (CB) and/or bronchodilator response were excluded resulting in 190 cases without COPD and 160 cases with COPD. Low attenuations areas (LAAs) (≤950 Hounsfield Unit (HU)) were identified and quantified at the level of individual lobes. Emphysema heterogeneity was defined in a manner that ranged in value from −100% to 100%. The association between emphysema heterogeneity and pulmonary function measures (e.g., FEV1% predicted, RV/TLC, and DLco% predicted) adjusted for age, sex, and smoking history (pack-years) was assessed using multiple linear regression analysis.ResultsThe majority (128/160) of the subjects with COPD had a heterogeneity greater than zero. After adjusting for age, gender, smoking history, and extent of emphysema, heterogeneity in depicted disease in upper lobe dominant cases was positively associated with pulmonary function measures, such as FEV1 Predicted (p<.001) and FEV1/FVC (p<.001), as well as disease severity (p<0.05). We found a negative association between HI% , RV/TLC (p<0.001), and DLco% (albeit not a statistically significant one, p = 0.06) in this group of patients.ConclusionSubjects with more homogeneous distribution of emphysema and/or lower lung dominant emphysema tend to have worse pulmonary function.
Highlights
As the most common phenotype of chronic obstructive pulmonary disease (COPD), emphysema is one of the leading cause of disability and death in the United States and worldwide [1]
Subjects with COPD and upper lung dominant emphysema (i.e., heterogeneity index (HI)%.0) had significantly higher FEV1% predicted (p = 0.01) and, lower Global Initiative for Obstructive Lung Disease (GOLD) scores (p = 0.02) than COPD subjects with lower lung dominant emphysema (Table 2)
The chance of a rapid decline in lung function is relatively lower in subjects with upper dominant and heterogeneous emphysema
Summary
As the most common phenotype of chronic obstructive pulmonary disease (COPD), emphysema is one of the leading cause of disability and death in the United States and worldwide [1]. This disease often goes undiagnosed for many years and irreversibly destroys lung parenchyma (alveoli), causes hyperinflation, and reduces lung elasticity [2]. Emphysema is typically diagnosed by pulmonary function tests (PFTs), medical history, and physical examination. It is widely believed that spatial distribution and pattern of emphysema may be important for understanding the observed lack of concordance between pulmonary function and the amount of diseased lung
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
