Noninvasive Imaging Biomarker Identifies Small Airway Damage in Severe Chronic Obstructive Pulmonary Disease

Evidence suggests damage to small airways is a key pathologic lesion in chronic obstructive pulmonary disease (COPD). Computed tomography densitometry has been demonstrated to identify emphysema, but no such studies have been performed linking an imaging metric to small airway abnormality. To correlate parametric response mapping (PRM) analysis to lung tissue measurements of patients with severe COPD treated by lung transplantation and control subjects. Resected lungs were inflated, frozen, and systematically sampled, generating 33 COPD ( = 11 subjects) and 22 control tissue samples ( = 3 subjects) for micro-computed tomography analysis of terminal bronchioles (TBs; last generation of conducting airways) and emphysema. PRM analysis was conducted to differentiate functional small airways disease (PRM ) from emphysema (PRM ). In COPD lungs, TB numbers were reduced ( = 0.01); surviving TBs had increased wall area percentage (