Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: An area of increased density at the right lung base persists . There is bibasilar subsegmental atelectasis as well . Lung volumes are low . The left hemidiaphragm is elevated . There is no free air beneath the diaphragm . Mediastinal structures are stable . A radiopaque catheter is projected over the right abdomen .
    OUTPUT:
    
No free air is identified . No significant change .