Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable upright chest film ___ at 19 :53 is submitted .
    OUTPUT:
    
Lung volumes remain low . Linear opacity at the left base likely reflects subsegmental atelectasis or scarring . No evidence of pulmonary edema . Overall cardiac and mediastinal contours are likely unchanged . Right PICC line has its tip in the right atrium . Pull - back of approximately 2 - 3 cm to position the tip in the distal SVC would be advised . Crowding of the pulmonary vasculature with no evidence of pulmonary edema . No pneumothorax .