Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior study , there has been interval increase in size of the right pleural effusion which is now large , with associated atelectasis of the right lung . Ill - defined retrocardiac opacity persists , and may reflect atelectasis , though infection is not excluded . There is no pneumothorax . Evaluation of the cardiomediastinal silhouette is limited due to the presence of the large effusion . There are no acute osseous abnormalities . Previously noted gastric tube has been removed .
    OUTPUT:
    
Large right pleural effusion , increased in size from the prior study , with associated compressive atelectasis . Retrocardiac opacity is unchanged , and may reflect atelectasis , though infection can not be excluded .