Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a subtle field of radiodensity projecting over the right upper lobe between the anterior second and third ribs . It is uncertain if this is sequela of previous radiation treatment , if any , or an acute pneumonia . Remainder of the lungs are unremarkable . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is within normal limits . The pleural surfaces are unremarkable .
    OUTPUT:
    
Right upper lobe opacity which may represent sequela of radiation treatment or acute pneumonia .