Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph was provided . Low lung volumes limit evaluation . Lungs appear grossly clear . Under penetration limits the assessment for subtle edema or pneumonia . Cardiomediastinal silhouette is normal . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Limited , negative .