Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly low . Heart size appears mildly enlarged . Mediastinal and hilar contours are grossly unremarkable . Pulmonary vasculature is not engorged . Minimal patchy opacities are seen in the lung bases , potentially atelectasis in the setting of low lung volumes . There may be a trace left pleural effusion . No definite pneumothorax is seen , though the left apex is somewhat obscured by an oxygen face mask over this region .
    OUTPUT:
    
Low lung volumes with probable bibasilar atelectasis . Possible trace left pleural effusion .