Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lordotic positioning and low inspiratory volumes . The left hemidiaphragm is elevated . There is upper zone redistribution , likely accentuated by low lung volumes . There is scattered subsegmental atelectasis or scarring in the right upper zone , right base and left base . Question sutures at the left base --___ there been prior surgery at the left lung base . Allowing for technique , the heart is not enlarged . No frank consolidation or gross effusion . No pneumothorax detected . Incidental note is made of a partially imaged right shoulder reverse arthroplasty .
    OUTPUT:
    
Low inspiratory volumes , with bibasilar and right upper zone atelectasis . No frank consolidation or gross effusion . Upper zone redistribution , which is likely accentuated by low inspiratory volumes , but no overt CHF .