Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: This been removed on the left . There is increased density the left lung base . A small pleural effusion persists . In addition , there is interval development of a very small left apical pneumothorax . The right lung appears clear is before . Mediastinal structures are unchanged . A right subclavian catheter remains in place . The bony thorax is grossly intact .
    OUTPUT:
    
Interval decrease in left pleural effusion . There is increased density in the underlying the left lung base . This may be due to residual atelectasis a re-expansion edema . There is a small apical pneumothorax as well . See accompanying CT report .