Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is subtle increased retrocardiac opacity which correlates with increased density projecting over the spine on the lateral view . Elsewhere the lungs are clear . The cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities identified .
    OUTPUT:
    
Left lower lobe opacity compatible with pneumonia in the proper clinical setting , recommend repeat after treatment to document resolution .