Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph provided . Lung volumes are low which limits evaluation . Allowing for this , there is no focal consolidation or definite signs of effusion or pneumothorax . The heart appears top normal , though this may be due to portable AP technique . The mediastinal contour is stable . No bony abnormalities are seen .
    OUTPUT:
    
Limited , negative .