Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are bibasilar opacities , new since the prior study , raising concern for pneumonia or aspiration . Underlying interstitial lung disease is not excluded although no evidence of such was seen on chest CT from ___ . No pleural effusion is seen . The cardiac and mediastinal silhouettes are stable and unremarkable . Relative lucency of the upper lung fields again suggests emphysema .
    OUTPUT:
    
Bibasilar opacities , new since the prior study , raising concern for pneumonia or aspiration . Underlying interstitial lung disease is not excluded although no definite evidence of such was reported on chest CT from ___ .