Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single frontal portable chest radiograph demonstrates fully expanded and clear lungs . Pleural surfaces are normal without evidence of pleural effusion or pneumothorax . Heart size , mediastinal contour , and hila are unremarkable . Limited assessment of the upper abdomen is unremarkable without free intraperitoneal air .
    OUTPUT:
    
No evidence of acute cardiopulmonary process .