Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to the prior radiograph performed on ___ , there has been interval development of a moderately - sized right pleural effusion . Left lung is essentially clear . No pneumothorax . Heart size is within normal limits . No acute osseous abnormalities identified .
    OUTPUT:
    
Interval development of a moderately - sized right pleural effusion since ___ .