Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a persistent very small left apical pneumothorax . A left - sided PICC line terminates at the cavoatrial junction . The patient is status post coronary artery bypass graft surgery . The cardiac , mediastinal and hilar contours appear stable . A left - sided chest tube and mediastinal drains have been removed . Since the prior study there is new mild volume loss at the left lung base with upward tenting of the left hemidiaphragm and increased streaky opacification suggesting worsening of atelectasis . Elsewhere , the lungs remain clear . Trace pleural effusions are present .
    OUTPUT:
    
1 . Stable very small left apical pneumothorax . 2 . Increased atelectasis at the base of the left lung .