Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right upper quadrant PTC drain and clips . Dual - lumen right IJ CVC terminates at the SVC RA junction . Heart size within normal . Low lung volumes with bibasilar atelectasis . No pneumothorax , focal consolidation of or pulmonary edema . Previously demonstrated retrocardiac opacity is improved .
    OUTPUT:
    
Low lung volumes . Interval improvement in previously demonstrated retrocardiac opacity .