Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A portable semi supine frontal chest radiograph again demonstrates and a left approach central venous catheter , which crosses midline and then heads superiorly , with the tip again likely within the right brachiocephalic vein . The azygos vein is also a consideration . The remainder of the exam is unchanged , with cardiomegaly and pulmonary edema .
    OUTPUT:
    
Status post replacement of a left approach central venous catheter , which again crosses midline and head superiorly . The tip may be in the right brachiocephalic vein versus azygos vein .