The following are radiological criteria to call a shadow on CXR
- Lobar or Segmental Density: The density should either correspond to
the lobe or lung segment.
- Air Bronchogram: Presence of air bronchogram would confirm
an alveolar process.
- No Loss of Lung Volume: Lung volumes increase in early stages of consolidation. In later stages there can be some amount of loss of lung volume due to secretions obstructing airways. As a general rule, there is no significant loss of lung volume in consolidation.