Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy and CABG . Low lung volumes are present which accentuates the size of the cardiac silhouette . Heart size appears mildly enlarged . Mediastinal contour is unremarkable . There is crowding of the bronchovascular structures with probable mild pulmonary vascular congestion . Patchy bibasilar airspace opacities could reflect atelectasis . Small bilateral pleural effusions are likely present . Degenerative changes are noted involving both glenohumeral and acromioclavicular joints . No acute osseous abnormalities visualized .
    OUTPUT:
    
Low lung volumes with bibasilar patchy opacities , likely atelectasis . Probable small bilateral pleural effusions and mild pulmonary vascular congestion .