Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild improvement in known right hydropneumothorax with improved aeration of the right lung base . The right pigtail pleural catheter appears to be slightly moved in positioning . The left lung is essentially clear . The heart size is unchanged . No pulmonary edema .
    OUTPUT:
    
Improvement in known right hydro pneumothorax with improved aeration of the right lung base .