Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Both lungs are well expanded and clear . There are no lung opacities concerning for pneumonia . Heart size , mediastinal and hilar contours are normal . Both lungs are remarkable for mild interstitial opacities which are unchanged since ___ . Ill - defined and discrete opacity in the right lower and medial lung has resolved . There is no pleural effusion .
    OUTPUT:
    
Since ___ , ill - defined opacity seen in the right medial lung base concerning for infection has resolved . Bilateral prominent interstitial markings are unchanged .