Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral chest radiograph demonstrate hyperinflated clear lungs . The heart is within upper limits of normal in size . Patient is status post median sternotomy . There is no pulmonary edema . There is no pleural effusion or pneumothorax . No acute osseous abnormality is detected .
    OUTPUT:
    
No acute intrathoracic abnormality . Probably COPD