Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and CABG . There are low lung volumes which accentuate the size of the cardiac silhouette which is likely mildly enlarged , with a left ventricular predominance . There is apparent widening of the superior mediastinum which also may be due to low lung volumes . There is crowding of the bronchovascular structures , without overt pulmonary edema . No pleural effusion or pneumothorax is seen . No definite focal consolidation is noted . Multilevel degenerative changes are present in the thoracic spine .
    OUTPUT:
    
Low lung volumes , without definite acute cardiopulmonary abnormality .