Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest demonstrate well expanded , clear lungs . Widened mediastinum is consistent with patient 's known type A aortic dissection . The heart is mildly enlarged . Status post median sternotomy . Metallic clips project over the right apex and axilla . There is no pneumothorax , pleural effusion , or consolidation .
    OUTPUT:
    
No acute cardiopulmonary process .