- Airspace filling
- segmental,
- subsegmental,
- lobular, or acinar (10 mm or less in diameter).
- centrilobular – poorly defined nodules
- with
- fluid,
- cells
- tissue
- extensive interstitial processes
- Resulting in
- homogeneous areas of consolidation
- poorly defined
- air bronchograms or
- air bronchiolograms
- no volume loss
- Differential diagnosis is very wide
- Therefore need clinical input
- Acute
- days to weeks
- most common causes
- edema,
- pneumonia, and
- hemorrhage
- Chronic
- weeks to months
- the differential may include
- granulomatous or inflammatory conditions,
- organizing pneumonia
- interstitial diseases,
- possibly caused by compressive atelectasis
- neoplasms such as
- lymphoma or
- bronchoalveolar cell carcinoma,
- lipoid pneumonia
- alveolar proteinosis,
