Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In the interval since the prior study , there has been development of a moderate left pleural effusion with overlying atelectasis , left base consolidation can not be excluded . There is slight blunting of the right costophrenic angle and a small pleural effusion may be present . The cardiac and mediastinal silhouettes are grossly stable . No evidence of pneumothorax is seen . No overt pulmonary edema is seen .
    OUTPUT:
    
1 . Moderate left pleural effusion with overlying atelectasis , new since the prior study . Underlying left base consolidation is difficult to exclude . 2 . Persistent slight blunting of the right costophrenic angle may be due to a small pleural effusion .