Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy for CABG . Heart remains mildly enlarged with left ventricular predominance . The patient is status post aortic valve replacement . The mediastinal contours are unchanged , with mild calcification of the aortic knob again demonstrated as well as a mildly tortuous course of the thoracic aorta . The pulmonary vascularity is not engorged . Streaky opacities in the lung bases are nonspecific , possibly reflecting atelectasis though infection can not be excluded . No pleural effusion or pneumothorax is visualized . There are no acute osseous abnormalities .
    OUTPUT:
    
Streaky bibasilar opacities , which could reflect atelectasis though infection can not be completely excluded .