PET, CT and MRI: summary for potential COPD biomarkers
| Modality | Type | Measurement | Potential biomarker of | Radiation | Cost | Time |
| PET | Functional 18F-FDG | Lung FDG uptake Large vessel FDG uptake | Pulmonary inflammation Risk of cardiovascular events | +++ | ++ | +++ |
| CT | Structural Insp only | Lung density Airway structure Vascular pruning | Emphysema, AECOPD risk, FEV1 decline COPD risk, FEV1 decline Mortality risk | + | + | + |
| Functional Insp/Exp | Low density on exp Deformation on image registration | Small airways disease/gas trapping Biomechanics | ++ | + | + | |
| MRI | Functional 3He/129Xe | Ventilation defect percent Dissolved phase | Ventilation heterogeneity Gas exchange | − | +++ | + |
PET: positron emission tomography; CT: computed tomography; MRI: magnetic resonance imaging; Exp: expiratory; Insp: inspiratory; FDG: fluorodeoxyglucose; FEV1: forced expiratory volume in 1 s; AECOPD: acute exacerbation of COPD.