Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy , aortic valve replacement , and CABG . Heart size is normal . The aorta remains tortuous but unchanged . Mediastinal and hilar contours are unremarkable . The pulmonary vasculature is normal . Streaky opacities are noted within the lung bases , potentially atelectasis though infection or aspiration can not be completely excluded . There is no pneumothorax or pleural effusion . No acute osseous abnormalities present . Remote right seventh rib fracture is demonstrated .
    OUTPUT:
    
Bibasilar streaky opacities , likely atelectasis though infection or aspiration can not be excluded .