Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single supine AP portable view of the chest was obtained . Patient 's overlying chin partially obscures medial lung apices . There are low lung volumes . Bibasilar atelectasis is seen . There is slight central pulmonary vascular prominence which may be due to vascular engorgement . No definite focal consolidation is seen . There is no large pleural effusion . Patient is status post median sternotomy . The cardiac silhouette is top normal to mildly enlarged . Aorta is calcified and tortuous .
    OUTPUT:
    
Low lung volumes . No overt pulmonary edema but suggestion of central pulmonary vascular engorgement . Top normal to mildly enlarged cardiac silhouette . Bibasilar atelectasis .