Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bilateral symmetric interstitial opacities have significantly improved since ___ but however are not completely resolved . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable . A drain is noted in the right upper abdominal quadrant .
    OUTPUT:
    
Substantial improvement in bilateral diffuse opacities since ___ , but not complete resolution