Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Previously described opacity in the both lower lungs which were concerning for pneumonia have significantly improved ; however , opacity in retrocardiac region , appreciated only on the lateral view is overall unchanged . No new lung opacities of concern . Top normal heart size , mediastinal and hilar contours are unchanged . There is no pleural abnormality .
    OUTPUT:
    
As compared to the ___ , bibasilar opacities have improved , whereas the retrocardiac opacity appreciated only on the lateral view is unchanged . Follow - up radiograph is recommended in three to four weeks to assess interval changes .