Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The left hemidiaphragm is elevated . There is bibasilar atelectasis . At the left base , there is blunting of the costophrenic angle and the possibility of early hazy opacity can not be excluded . There is mild upper zone redistribution , without overt CHF . No gross effusion or pneumothorax detected . Possible mild cardiomegaly . Right IJ central line tip lies in the region of the cavoatrial junction .
    OUTPUT:
    
Upper zone redistribution . Early hazy opacity left base can not be excluded . Probable small left effusion .