Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable AP upright view of the chest was obtained . Lung volumes are lower compared to the prior study ; however , there is no evidence of focal consolidation , pleural effusion , or pneumothorax . The cardiomediastinal contour is unremarkable . No overt signs of pulmonary edema .
    OUTPUT:
    
No acute intrathoracic abnormality . Low lung volumes .