Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette is upper limits of normal in size allowing for accentuation by AP and apical lordotic technique . A nonspecific left retrocardiac opacity has substantially improved since the recent study , but a patchy right lower lobe opacity has worsened . Small bilateral pleural effusions have also increased in size slightly .
    OUTPUT:
    
Bibasilar opacities , improved on the left and worse on the right . This is most likely due to atelectasis , but aspiration or aspiration pneumonia could produce a similar radiographic appearance . Slight increase in bilateral pleural effusions .