Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left - sided chest tube remains in place . A left subclavian central venous catheter ends in the low SVC . The previous small to moderate left apical pneumothorax has substantially decreased , and is now small in size . Left lung base linear atelectasis is unchanged . The lungs are otherwise clear . The heart and mediastinum are within normal limits .
    OUTPUT:
    
Substantial interval decrease in left apical pneumothorax , which is now small .