Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Small - to - moderate left pleural effusion is unchanged since ___ . Since the prior radiograph , there is some improvement in mild interstitial edema . Opacities in the left mid lung zone likely atelectasis . There are suture lines seen in the left upper lung with associated opacifications , likely surgical . Bubbles of air at the apex in the pleural space are unchanged . The right lung is clear . Cardiomediastinal silhouette is unchanged .
    OUTPUT:
    
1 . Stable small - to - moderate left pleural effusion . 2 . Small air bubbles in the pleural space in the apex on the left , unchanged . 3 . Mild improvement in interstitial edema .