Airway Quantification Using Ultra-Low-Dose Computed Tomography Correlates With Pulmonary Function Indices in Patients With Asthma.

This prospective cohort study evaluated ultra-low-dose computed tomography (ULDCT) as a tool for quantifying airway and parenchymal abnormalities in 24 patients with asthma. Quantitative indices included the percentage of low-attenuation area (LAA%) for emphysema, parametric response mapping for functional small airway disease (PRMfSAD), and Pi10 for airway thickening, assessed against spirometric parameters at baseline and 1-year follow-up. PRMfSAD showed the strongest and most consistent associations with forced expiratory volume in 1 second (FEV₁) %pred, forced expiratory flow between 25% and 75% (FEF25-75) %pred, and the ratio of FEV₁ to forced vital capacity (FVC). The LAA% correlated mainly with the ratio of FEV₁ to FVC. Pi10 showed significant association only with FEF25-75%pred in the multivariable model. Despite dose-related variability in raw values, correlations with lung function parameters remained stable over time. These findings suggest that indices derived from ULDCT, particularly PRMfSAD, provide practical low-radiation biomarkers of lung function abnormalities in asthma.