Using pulmonary imaging to move chronic obstructive pulmonary disease beyond FEV1

Area of Science:

• Pulmonary medicine
• Medical imaging
• Respiratory diseases

Background:

• For decades, Forced Expiratory Volume in 1 second (FEV1) has been the primary measure for chronic obstructive pulmonary disease (COPD) research and therapy development.
• However, FEV1 has a weak correlation with symptoms and outcomes and does not capture COPD's heterogeneity or phenotypes.
• Current COPD therapies primarily focus on treatments that acutely improve FEV1.

Purpose of the Study:

• To highlight the limitations of FEV1 in assessing COPD.
• To introduce thoracic imaging as a method to visualize and quantify COPD's structural and functional consequences.
• To discuss the implications of imaging findings for future COPD biomarker and therapy research.

Main Methods:

• Review of pulmonary imaging techniques including X-ray computed tomography and various magnetic resonance imaging methods (e.g., 1H, 129Xe, 3He, O2, 19F).
• Focus on imaging's ability to quantify airway remodeling, emphysema, regional ventilation abnormalities, and gas trapping.
• Application of imaging in both ex-smokers with normal FEV1 and COPD patients with mild lung function decline.

Main Results:

• Thoracic imaging provides direct visualization of structural and functional changes in COPD.
• Imaging can quantify regional ventilation defects, gas trapping, emphysema, and airway remodeling with high resolution.
• These methods are valuable for understanding COPD mechanisms, progression, and treatment response, especially when FEV1 is insufficient.

Conclusions:

• Pulmonary imaging offers a more comprehensive assessment of COPD than FEV1 alone.
• Imaging can reveal disease heterogeneity and phenotypes not captured by spirometry.
• Future research should leverage advanced imaging findings to develop targeted biomarkers and therapies for improved COPD outcomes.