Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is moderately enlarged but unchanged in size . A left - sided PICC takes a sharply posterior course on the lateral view and may terminate within the proximal azygous vein . This is not definitely confirmed on the frontal view . There is no pneumothorax . The lungs are clear .
    OUTPUT:
    
Left - sided PICC may terminate at the entrance to the azygos vein , though this is not definitely seen on the frontal view .