Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable chest radiograph demonstrates clear lungs . There is no pleural effusion or pneumothorax . The heart size is normal . The cardiac , hilar , mediastinal contours are unremarkable . There are no rib fractures identified .
    OUTPUT:
    
No acute cardiopulmonary abnormality . No displaced rib fractures seen .