Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and aortic valve replacement . Heart size is mildly enlarged but unchanged . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is not engorged . No focal consolidation , pleural effusion or pneumothorax is identified . Linear opacity within the right middle lobe likely reflects scarring , not substantially changed from the prior CT . No acute osseous abnormality is detected . There are moderate degenerative changes within the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .