Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest demonstrate a right - sided pleural catheter in unchanged position . The pleural effusion has decreased in size , now only a small amount remains , but there is now air within the pleura . The chest is otherwise unchanged , including right basal atelectasis , and clear left lung . Cardiac size remains stable .
    OUTPUT:
    
Interval decrease in the amount of fluid but increase in the amount of air within the right pleura compatible with a small hydropneumothorax .