| Key
Facts |
- Nonspecific pathologic
reaction to smoke and dust
- Clustered macrophages
surrounding respiratory bronchioles
- Extension to interstitium:
Respiratory bronchiolitis associated interstitial lung disease (RB-ILD)
- Extension to airspace:
Desquamative interstitial pneumonia (DIP)
|
| Imaging
Findings |
Chest
radiography
- Usually normal
or mild hyperinflation
- Mild interstitial
thickening (RB-ILD)
- Mild ground glass
opacities (DIP)
CT/HRCT
- Centrilobular micronodules
(rare tree-in-bud) predominantly upper lobes
- Mosaic perfusion
- Lucent lung, small
vessels in lucent lung
- Expiratory scanning
useful to differentiate from vascular disease
|
| Differential
Diagnosis |
- Asthma
- Panlobular emphysema
- Langerhans cell
granulomatosis
- Viral pneumonia
- Hypersensitivity
pneumonitis
|
| Pathological
Features |
- Pigmented “dirty”
marcophages surrounding respiratory bronchioles
- May be precursor
of centriacinar emphysema
|
| Clinical
Presentation |
- Respiratory bronchiolitis
usually asymptomatic
- Cough and dyspnea
|
| References |
Desai
SR et al. Small airways disease: Expiratory computed tomography comes
of age. Clin Radiol 52: 332-7, 1997
|
