Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bilateral lung volumes are low . Increased retrocardiac opacity , in appropriate clinical setting , is concerning for pneumonia . Left upper and right lung are clear . There is no pleural effusion . Mediastinal and hilar contours are normal .
    OUTPUT:
    
Increased retrocardiac opacity in an appropriate clinical setting is concerning for pneumonia . Clinical correlation is suggested .