Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP supine portable chest radiograph is obtained . Lung volumes are low though allowing for this , the lungs appear clear . No signs of CHF or pneumonia . No pleural effusion or pneumothorax . Heart and mediastinal contours appear normal . Bony structures are intact .
    OUTPUT:
    
No acute intrathoracic process .