Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . The cardiac silhouette size remains at least mildly enlarged . Mediastinal contours are unchanged , with mild calcification of the aortic arch . Mild pulmonary edema appears slightly progressed compared to the previous exam . Small pleural effusion is again demonstrated , with bibasilar airspace opacities most likely reflective of atelectasis . The left hemidiaphragm remains elevated . No pneumothorax is present . Multilevel degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Mild congestive heart failure , slightly progressed compared to the previous exam , with small left pleural effusion . Mild bibasilar atelectasis .