FINDINGS:
The heart is at the upper limits of normal size.  The mediastinal
 and hilar contours appear unchanged.  There is slight relative elevation of
 the right hemidiaphragm compared to the left, as before.  A fine reticular
 interstitial abnormality has overall increased substantially and again has an
 asymmetric appearance with greater involvement of the left lung than right, as
 was seen previously.  The distribution is predominantly peripheral. 
 Otherwise, there has been little if any change.  There is no pleural effusion
 or pneumothorax.  Bony structures are unremarkable.

IMPRESSION:
Increased reticular abnormality with a similar peripheral and
 asymmetric distribution, worse in the left lung than right.  This appearance
 suggests worsening of underlying interstitial lung disease.  The possibility
 of diffuse acute interstitial process superimposed on underlying interstitial
 lung disease, such as interstitial edema or diffuse atypical infection, could
 also be considered versus worsening of the chronic abnormality.