Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is slightly rotated . The heart size is normal . The hilar and mediastinal contours are within normal limits . There has been interval increase in central pulmonary vessel prominence and interstial opacities , representing mild edema . Increased linear atelectasis at the left base is seen . There is no pneumothorax or large pleural effusion . No free intrabdominal air is detected on this upright study .
    OUTPUT:
    
Mild interstial edema .