Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright chest radiograph was provided . Lung volumes are low . There is no focal consolidation , effusion , or pneumothorax . There is bronchovascular crowding or mild atelectasis likely accounting for the mild linear densities in the lower lungs . Cardiomediastinal silhouette appears normal . Bony structures are intact .
    OUTPUT:
    
Limited , negative .