History 1:  Chronic cough

History 2:  

Acute chest pain and shortness of breath

History 3:  

Asymptomatic (CT done as normal control for a clinical study)

ALVEOLAR: fluffy, ill-defined margins, air-bronchograms

INTERSTITIAL: linear, reticular opacities, Kerley B lines

alveolar-sarcoidosis

interstitial-idiopathic pulmonary fibrosis

alveolar-acute pulmonary edema

interstitial-chronic pulmonary edema

alveolar -pulmonary lymphoma

interstitial-drug toxicity or hypersensitivity