Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been significant improvement in a left pneumothorax with only a small apical component remaining . The cardiomediastinal silhouette and hilar contours are stable . Bibasilar atelectatic changes are stable . A small left pleural effusion is unchanged . A left chest tube remains in place . Hyperlucent right lung apex corresponds to a large bulla on prior chest CT .
    OUTPUT:
    
Significant improvement of left pneumothorax with remnant small apical component . Persistent bibasilar atelectasis and small left effusion .