Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable AP upright radiograph through the chest demonstrates clear lungs bilaterally . Cardiomediastinal and hilar contours are within normal limits . There is no large pleural effusion . There is no pneumothorax . Visualized osseous structures demonstrate no acute abnormality .
    OUTPUT:
    
No acute intra thoracic abnormality .