Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Analysis is performed in direct comparison with the next preceding similar study of ___ . Status post sternotomy and moderate cardiac enlargement as before . The previously described loculated pneumothorax on the left side remains rather unchanged . The air - fluid level within the pneumothorax is at a slightly higher level indicating filling - in of the isolated cavity . There may be some improved aeration in the area of the previously identified trapped left lower lung , but aCT - chest exam would be required to make such observation conclusively .
    OUTPUT:
    
Grossly stable chest findings with left - sided loculated pneumothorax and trapped lung .