Consolidation
Updates to Article Attributes
Consolidation describes increased lung attenuation sufficient to obscure bronchial walls and blood vessels (on non-enhanced CT). Patent airways can be identified by the endoluminal gas as an air bronchogram. Consolidation can be caused by any process that evacuates alveolar air such as pneumonia, when air is replaced by inflammatory exudate, or tumour, when air is replaced by tumour cells 3.
On radiographs, consolidation appears as air bronchograms within opacity which is otherwise homogeneous.
Pathology
Aetiology
The opacification is caused by fluid or solid material within the airways that causes a difference in the relative attenuation of the lung:
transudate, e.g.pulmonary oedemasecondary toheart failurepus, e.g. bacterialpneumoniablood, e.g. pulmonary haemorrhage
cells, e.g.
bronchoalveolar carcinomaprotein, e.g.alveolar proteinosisadenocarcinomafat, e.g. lipoid pneumonia
gastric contents, e.g. aspiration pneumonia
protein, e.g. alveolar proteinosis
pus, e.g. bacterial pneumonia
transudate, e.g. pulmonary oedema secondary to heart failure
water, e.g. drowning
When considering the likely causes of airspace opacification, it is useful to determine chronicity (by reviewing previous radiographs) and considering laterality.
Additionally, the presence of mediastinal or hilar lymphadenopathy further refines the massive list of differentials:
Patterns of disease
On chest radiography a number of patterns are recognised:
-<li><p>transudate, e.g. <a href="/articles/pulmonary-oedema">pulmonary oedema</a> secondary to <a href="/articles/heart-failure">heart failure</a></p></li>-<li><p>pus, e.g. bacterial <a href="/articles/pneumonia">pneumonia</a></p></li>-<li><p>cells, e.g. <a href="/articles/adenocarcinoma-in-situ-minimally-invasive-adenocarcinoma-and-invasive-adenocarcinoma-of-lung-1">bronchoalveolar carcinoma</a></p></li>-<li><p>protein, e.g. <a href="/articles/pulmonary-alveolar-proteinosis">alveolar proteinosis</a></p></li>- +<li><p>cells, e.g. <a href="/articles/adenocarcinoma-in-situ-minimally-invasive-adenocarcinoma-and-invasive-adenocarcinoma-of-lung-1">adenocarcinoma</a></p></li>
- +<li><p>protein, e.g. <a href="/articles/pulmonary-alveolar-proteinosis">alveolar proteinosis</a></p></li>
- +<li><p>pus, e.g. bacterial <a href="/articles/pneumonia">pneumonia</a></p></li>
- +<li><p>transudate, e.g. <a href="/articles/pulmonary-oedema">pulmonary oedema</a> secondary to <a href="/articles/heart-failure">heart failure</a></p></li>