Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The left - sided chest drain has been removed . Surgical material projecting over the upper and mid aspect of the left lung in keeping with previous VATS . Small left apical pneumothorax measuring 10 mm in the craniocaudal plane . Increased density in the left lower lobe most likely representing atelectasis . Possible small associated effusion . The right lung is clear . No subdiaphragmatic free air . No sinister bony lesions .
    OUTPUT:
    
Left apical pneumothorax measuring 10 mm in the craniocaudal plane . Atelectatic changes in the left lower lobe .