Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes remain extremely low . Previously seen atelectasis and pleural effusion at the left base has improved . Mild pulmonary edema persists . There is no focal consolidation , pulmonary edema , or pneumothorax .
    OUTPUT:
    
The left lower lung is better aerated and the left effusion has decreased however lung volumes remain very low . Mild pulmonary edema persist .