Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to chest x-ray from earlier same day , there is improved aeration of the left upper lobe . There is persistent left lower lobe collapse with associated effusion . Endotracheal tube and nasogastric tube in similar position . Minimal subsegmental atelectasis in the right lower lobe .
    OUTPUT:
    
Slight improved aeration of the left upper lobe when compared to the prior .