Opacity

Mass vs. Infiltrate

 

 

The basic diagnostic instance is to detect an abnormality.  In both of the cases above, there is an abnormal opacity.  It is most useful to state the diagnostic findings as specifically as possible, then try to put these together and construct a useful differential diagnosis using the clinical information to order it.

In each of the cases above, there is an abnormal opacity in the left upper lobe.  In the case on the left, the opacity would best be described as a mass because it is well-defined.  The case on the right has an opacity that is poorly defined.  This is airspace disease such as pneumonia.