Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single AP upright portable view of the chest was obtained . A left - sided chest catheter is seen extending into the lateral left upper hemithorax . As compared to the prior study , there has been significant reexpansion of the left lung with a trace residual left apical pneumothorax remaining . There is minimal elevation of the left hemidiaphragm and left base atelectasis . Right lung is clear .
    OUTPUT:
    
Interval expansion of the left lung with significant reduction in pneumothorax with only trace left apical pneumothorax remaining .