Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph obtained . Lung volumes are low , though lungs appear clear . Cardiomediastinal silhouette normal . No pleural effusion or pneumothorax . Bony structures appear intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
No acute intrathoracic process .