Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright chest radiograph was obtained . Low lung volumes and slightly underpenetrated technique somewhat limits the evaluation . Allowing for this , there is no definite sign of pneumonia or overt CHF . Cardiomediastinal silhouette is stable . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Limited , negative .