Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: 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 .
    OUTPUT:
    
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 .