Chest X Ray - Four Patterns

Chest X Ray - Four Patterns

Lung abnormalities with an increased density - also called opacities - are the most common.
A practical approach is to divide these into four patterns:

1. Consolidation
2. Interstitial
3. Nodules or masses
4. Atelectasis 
   
   
   Whenever you see an area of increased density within the lung, it must be the result of one of these four patterns. 
   
   
   Consolidation - any pathologic process that fills the alveoli with fluid, pus, blood, cells (including tumor cells) or other substances resulting in lobar, diffuse or multifocal ill-defined opacities. 
   
   
   Interstitial - involvement of the supporting tissue of the lung parenchyma resulting in fine or coarse reticular opacities or small nodules. 
   
   
   Nodule or mass - any space occupying lesion either solitary or multiple. 
   
   
   Atelectasis - collapse of a part of the lung due to a decrease in the amount of air in the alveoli resulting in volume loss and increased density.