Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral upright radiograph through the chest demonstrates clear lungs bilaterally . When compared to prior radiograph dated ___ , there is improved aeration of the left lower base . The cardiomediastinal and hilar contours are stable in appearance . No overt pulmonary edema is identified . Osseous structures demonstrates no acute abnormality . No free air is identified . No free air is seen under the right hemidiaphragm .
    OUTPUT:
    
No acute intrathoracic abnormality .