Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . Left - sided AICD / pacemaker device is noted in unchanged positions in the right atrium and right ventricle . Lung volumes are low . This accentuates the size of the cardiac silhouette which is mild to moderately enlarged . Mediastinal contours are unchanged . There is crowding of the bronchovascular structures as a result of low lung volumes . No pulmonary edema is demonstrated . Streaky opacities in the lung bases are most likely reflective of atelectasis . No pleural effusion or pneumothorax is identified . Cholecystectomy clips are noted in the right upper quadrant of the abdomen .
    OUTPUT:
    
Low lung volumes with probable bibasilar atelectasis .