Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest demonstrate relatively low lung volumes , with no evidence of pneumonia , pulmonary edema , or pneumothorax . Bilateral pleural thickening is unchanged . Median sternotomy wires and mediastinal clips are again seen , as well as a prosthetic aortic valve . The heart is enlarged , but unchanged since the prior study . Aortic calcifications are noted .
    OUTPUT:
    
No acute cardiopulmonary process .