Table 2.

Visual Features Evaluated in the COPDGene Study

Visual Metric	Definition	Comments
Centrilobular emphysema (8)	Focal lucencies in the lung, classified as trace, mild centrilobular, moderate centrilobular, confluent, and advanced destructive	Present in up to 44% of cigarette smokers without COPD. Associated with increased risk of mortality and increased risk of lung cancer
Panlobular emphysema	Diffuse decrease in density in the lung, often lower lung predominant	This term is usually reserved for emphysema occurring in patients with known alpha-1 antitrypsin deficiency
Paraseptal emphysema	Subpleural lucencies, classified as mild or substantial	—
Bronchial wall thickening	Subjective thickening of the walls of bronchi, classified as probable or definite	—
Interstitial lung abnormalities (60)	Nondependent abnormalities affecting >5% of any lung zone, including reticular, ground-glass changes, centrilobular nodularity, nonemphysematous cysts, honeycombing, and traction bronchiectasis	Associated with restrictive lung physiology and with increased risk of mortality

Definition of abbreviation: COPD = chronic obstructive pulmonary disease; COPDGene = Genetic Epidemiology of COPD.