Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph demonstrates clear lungs bilaterally . Cardiomediastinal and hilar contours are within normal limits . There is no pleural effusion , pneumothorax , or evidence of pulmonary edema . Imaged upper abdomen is unremarkable .
    OUTPUT:
    
No acute intrathoracic abnormality .