Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable radiograph of the chest was acquired . A linear horizontal artifact extends across the lower portion of this image . The inferior - most portion of the left costophrenic angle is excluded from this radiograph . The lungs are well expanded . There is minimal bibasilar atelectasis . The lungs are otherwise clear . The heart size is normal . Tortuosity of the thoracic aorta is redemonstrated . There are no definite pleural effusions . No pneumothorax is seen .
    OUTPUT:
    
No evidence of acute cardiopulmonary process .