Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left base opacification , not clearly seen on the lateral radiograph is new since ___ and could represent atelectasis or infection in the appropriate clinical setting . There is persistent right mid lung opacity laterally which has persisted since ___ . The lungs are otherwise clear without pulmonary edema , pleural effusion or pneumothorax . The the heart size is top normal . The aorta is tortuous . There is no free air .
    OUTPUT:
    
A left base opacity , not clearly seen on the lateral radiograph , is new since ___ could represent atelectasis or infection in the appropriate clinical setting .