Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy , CABG , and aortic valve replacement . Mild cardiomegaly is re - demonstrated . The mediastinal contours are similar . Crowding of bronchovascular structures is due to low lung volumes . Patchy atelectasis is also noted without focal consolidation . No pleural effusion or pneumothorax is present . Mild degenerative changes are seen in the thoracic spine . No displaced fractures are identified .
    OUTPUT:
    
1 . Mild cardiomegaly without congestive heart failure . 2 . Mild bibasilar atelectasis . No radiographic evidence for pneumonia . 3 . No displaced rib fracture identified . If there is continued concern for a rib fracture , consider a dedicated rib series