Infectious Bronchiolitis

Subacute Hypersensitivity Pneumonitis

Aspiration

Respiratory Bronchiolitis

Follicular Bronchiolitis

Laryngeal Papillomatosis

Vasculitis

Metastatic Pulmonary Calcification

Pulmonary Sarcoidosis

Silicosis/Coal Worker’s Pneumoconiosis

Lymphocytic Interstitial Pneumonia

Nodules (< 1 cm diameter) centered on small airways or blood vessels (centrilobular)

Mosaic attenuation, tree-in-bud opacities, air-trapping, bronchiectasis

Ground-glass nodules usually signify bronchovascular pattern

Lymphatic pattern may have subpleural and fissural nodules that comprise > 10% of total nodules

Lymphatic pattern may not involve peripheral lymphatics

Bronchovascular pattern may have signs of small airways obstruction

Ground-glass nodules usually signify bronchovascular pattern

Centrilobular nodules clustered like grapes

Hematogenous nodules may have feeding vessels

Bronchovascular pattern may have signs of small airways obstruction

Ground-glass nodules usually signify bronchovascular pattern

For less profuse nodules, separation of centrilobular nodules from random difficult

Classically described with mycobacterial disease (endobronchial spread) but nonspecific

Upper lobe centrilobular indistinct ground-glass nodules

Confluent lower lobe ground-glass nodules

Lobular air-trapping on exhalation CT

Rare in smokers

Tree-in-bud opacities especially common in chronic aspiration of legumes

Primarily involves gravity-dependent lung regions

Upper lobe faint centrilobular ground-glass nodules

May be precursor to centrilobular emphysema

Smoking-related lung disease, responds to smoking cessation

Lymphoid hyperplasia of bronchus-associated lymphoid tissue (BALT)

Associated with collagen vascular diseases (rheumatoid arthritis), AIDS, infections, hypersensitivity reaction

Centrilobular nodules most common, usually associated with subpleural nodules and ground-glass opacities

Usually associated with nodules within airways

Distribution often in gravity-dependent lung regions

Nodules may cavitate

Centrilobular nodules from hemosiderin-laden macrophages

Nodules follow episodes of hemorrhage (seen as consolidation and ground-glass opacities)

Usually seen in conditions associated with hypercalcemia (especially renal failure)

Typically upper lobes

Nodules often clustered into rosettes (resembles mulberry)

If disease does not involve peripheral lymphatics, lymphatic pattern may be indistinguishable from bronchovascular pattern