Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since ___ , the left lower lung aeration has improved . Opacification of the left hemithorax , which is due to combination of pleural effusion and atelectasis , improved with improved aeration of the mid and lower lungs . Persistent mediastinal shift to the left side . There is no pneumothorax . The right costophrenic angle is chronic and unchanged since at least ___ .
    OUTPUT:
    
Since ___ , left lung opacity due to a combination of loculated pleural effusion and left lower lung atelectasis is better with improved aeration of the left lung . Mediastinal shift to the left side persists . Right lung is clear . No pneumothorax .