Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Relatively low lung volumes are seen . Irregular opacity projecting over the left upper lung as well as bibasilar opacities are similar compared to prior x-ray . Findings may be due to combination of atelectasis or chronic changes from prior infection . The cardiomediastinal silhouette is unchanged . No acute osseous abnormalities .
    OUTPUT:
    
Persistent bibasilar and left upper lung interstitial abnormality which have not significantly changed since ___ exam . Consider PA and lateral for better delineation .