Simplified definitions

EntityPopulationDiagnostic criteriaDefinition
ILAOnly individuals without known or suspected ILD#Clinical-radiological entityIncidental finding of CT abnormalities affecting more than 5% of any lung zone
Early ILDPre-clinical ILDIndividuals at risk for ILDClinical-radiological-pathological entityAny ILD in asymptomatic patients with preserved lung function
Subclinical ILDIndividuals NOT at risk for ILD
Mild ILDAll individualsClinical-radiological-pathological entityAny clinically significant ILD with minor symptoms and/or trivial PFT abnormalities

ILA: interstitial lung abnormalities; ILD: interstitial lung disease; CT: computed tomography; PFT: pulmonary function test. #: abnormalities identified during screening for ILD in high-risk groups (e.g. those with rheumatoid arthritis, systemic sclerosis or familial ILD) are not considered as ILA because they are not incidental.