Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph provided . Lung volumes are low with basilar atelectasis . Given the opacity in the lower lungs , pneumonia can not be entirely excluded . The heart size can not be assessed . The mediastinal contour is stable . No pneumothorax .
    OUTPUT:
    
Low lung volumes with bibasilar atelectasis , pneumonia can not be excluded .