Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is bibasilar opacity , left worse than right . The hilar and mediastinal silhouette are stable without evidence of pulmonary edema . The heart size stably mildly enlarged . There is no pleural effusion or pneumothorax . Patient is status post median sternotomy with wires aligned and intact .
    OUTPUT:
    
Bibasilar atelectasis , left worse than right . However , pneumonia in the left lower lobe can not be excluded .