Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy . Heart size is normal . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . Lung volumes are low . Mild atelectasis is noted at the lung bases , with no focal consolidation . No pleural effusion or pneumothorax is present . There is no focal consolidation . There are no concerning osseous abnormalities .
    OUTPUT:
    
Low lung volumes with mild bibasilar atelectasis .