Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is essentially complete opacification of the left hemithorax . A small faint area of residual lucency is seen in the upper zone , but this is decreased compared with ___ . The mediastinum remains grossly midline , though the possibility of slight rightward shift of mediastinum would be difficult to exclude . The right lung remains grossly clear , without CHF , focal infiltrate or effusion . Possible minimal atelectasis at right lung base .
    OUTPUT:
    
Worsening opacification of the left hemithorax . Only minimal residual aeration present . Right lung grossly clear .