Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to previous exam , there has been interval progression of the left basilar opacity which now silhouette the hemidiaphragm . There is suggestion of possible associated volume loss / atelectasis in left lower lobe given posterior displacement of the fissure . Elsewhere , lungs are clear . Cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities .
    OUTPUT:
    
Left lower lobe consolidation compatible with pneumonia in the proper clinical setting . Likely a component of atelectasis . Please repeat after treatment to document resolution .