Acute<unk><unk> 
Chest radiographs in affected patients may be normal; thin-section CT can be helpful in these patients for showing characteristic centrilobular  ground glass or nodular opacities.
When abnormal, chest radiographs typically show focal or diffuse heterogeneous or homogeneous opacities.
Subacute<unk><unk> 
Patients with subacute disease usually have a more indolent clinical presentation. Nodular opacities are a characteristic feature on chest radiographs and CT. Centrilobular ground-glass or nodular opacities on CT suggest the diagnosis.
Head cheese sign
Chronic<unk><unk> 
Chronic disease typically manifests with upper lung zone fibrosis. Characteristic distribution and presence of centrilobular nodules on CT help distinguish chronic<unk><unk>  from idiopathic pulmonary fibrosis.
Hypersensitivity pneumonitis CT
Eosinophilic pneumonia CT
Cryptogenic organizing pneumonia MRI
Chronic bronchitis CT
Cryptogenic organizing pneumonia CT
Bronchiolitis CT scan
Lipoid pneumonia MRI
Idiopathic pulmonary fibrosis CT