Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . Left - sided dual - chamber pacemaker is noted with leads terminating in the right atrium and right ventricle . Moderate cardiomegaly is unchanged with left atrial enlargement . The mediastinal and hilar contours are within normal limits . No pulmonary edema is visualized . Lung volumes are low with mild bibasilar opacities likely reflective of atelectasis . No pneumothorax or pleural effusion is identified . There are no acute osseous abnormalities . No displaced rib fractures are seen .
    OUTPUT:
    
Low lung volumes with mild bibasilar atelectasis . No displaced fracture seen . If there is continued concern for a rib fracture , then a dedicated rib series is recommended .