Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lordotic positioning . Heart size at the upper limits of normal . Aorta is tortuous and slightly unfolded . There is slight upper zone redistribution , without other evidence of CHF . No focal infiltrate , effusion , or pneumothorax is detected . Minimal scarring at the left lung base laterally noted .
    OUTPUT:
    
No acute intrathoracic abnormality identified .