Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest demonstrate persistent opacification of the left base which likely represents a small pleural effusion and adjacent atelectasis . Right basilar atelectasis is unchanged . The cardiomediastinal and hilar contours are unchanged . No pneumothorax .
    OUTPUT:
    
Persistent opacification of the left base which likely represents a small pleural effusion and adjacent atelectasis .