This is a basic article for medical students and other non-radiologists
Air-space opacification is a descriptive term that refers to filling of the lung parenchyma with material that attenuates x-rays more than the unaffected surrounding lung tissue. It is the radiological correlate of the pathological diagnosis of pulmonary consolidation.
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Reference article
This is a summary article; read more in our article on air-space opacification.
Summary
- anatomy
-
pathophysiology
- material fills the lung parenchyma
- fluid: pulmonary edema
- pus: pneumonia
- blood: pulmonary hemorrhage
- cells: cancer
- protein: alveolar proteinosis (rare)
- distribution
- patchy
- air-space filling is incomplete and non-contiguous
- residual gas within the alveoli
- lobar
- complete filling of a lobe of the lung
- clear delineation between consolidation and adjacent gas-filled structures
- the remainder of the lung or in bronchi traveling through the lobe
- no margin between consolidation and other soft-tissue density structures
- mediastinum or diaphragm
- multifocal
- symmetrical or asymmetrical
- perihilar or peripheral
- often non-specific without clinical history and examination findings
- patchy
- material fills the lung parenchyma
-
role of imaging
- confirm air-space opacification and differentiate from atelectasis or pleural effusion where possible
- help to determine the cause, e.g. other signs of heart failure
- identify complications, e.g. abscess formation
- demonstrate accompanying pathology, e.g. effusion or empyema
- determine severity and extent, e.g. number of lobes involved, uni- or bilaterality
- common pathology
Radiographic features
Chest x-ray
- normal air-filled lung is black
- air-space opacification is radiopaque (white)
- aerated bronchi
CT chest
- air-space opacification looks very similar to the chest x-ray
- distribution can be assessed more accurately
- assessment of complications is more accurate