Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral views of the chest demonstrate low lung volumes which exaggerate the bronchovascular structures as well as cause bibasal atelectasis . Heart size is mildly enlarged . The patient is status post median sternotomy and CABG . There are no focal opacities which are concerning for pneumonia . There is no overt pulmonary edema and there is no pleural effusion . There is no free air .
    OUTPUT:
    
No evidence of acute cardiopulmonary process given low lung volumes .