Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to the prior examination dated ___ , there has been no significant interval change . Again , a diffuse background interstitial abnormality is noted . Multiple opacities within the right upper lobe , predominantly noted peripherally , are unchanged from ___ . No lobar consolidation definitive for pneumonia is identified . Left lower lobe atelectasis is slightly improved from the prior examination . The cardiomediastinal silhouette is unchanged .
    OUTPUT:
    
Essentially unchanged , background interstitial abnormality without definitive focal lobar consolidation .