Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to the prior study , bibasilar opacities have substantially improved . A small right pleural effusion appears smaller . No pleural effusion is appreciated on the left . There is no pneumothorax . Cardiomediastinal silhouette is stable .
    OUTPUT:
    
1 . Substantial improvement in bibasilar opacities 2 . Persistent small right pleural effusion .