Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy , CABG and aortic valve replacement . Heart size is mildly enlarged . The aorta is tortuous and diffusely calcified . Mediastinal and hilar contours are otherwise unremarkable . There is no pulmonary edema . Streaky opacities in the lung bases likely reflect atelectasis . No focal consolidation , pleural effusion or pneumothorax is visualized . There are multilevel degenerative changes in the thoracic spine .
    OUTPUT:
    
Streaky bibasilar opacities likely atelectasis .