Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Compared to prior study , the left pigtail pleural cathter position is slightly lower and more lateral in position . A small left apical pneumothorax has increased in size . There is no shift of mediastinal structures . There are persistent bibasilar linear opacities , likely reflective of atelectasis , which are similar in appearance compared to prior study .
    OUTPUT:
    
Small left apical pneumothorax .