Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and CABG . Cardiac silhouette size remains mildly enlarged but unchanged . Mediastinal and hilar contours are normal . Pulmonary vasculature is normal . Subsegmental atelectasis is noted in the left lung base . No focal consolidation , pleural effusion or pneumothorax is identified . No displaced fractures are visualized . There are mild degenerative changes noted in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary abnormality .