Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest show small bilateral pleural effusions . An ill - defined opacity at the right lung base is consistent with atelectasis . Opacities in the left lung base may represent atelectasis , but pneumonia can not be excluded . No pneumothorax is present . The pulmonary vasculature is not engorged . The cardiac silhouette is top normal in size . The patient is status post median sternotomy and CABG with pneumopericardium noted on the lateral radiograph . An aortic valve prosthesis is in place . Surgical clips are noted in the thoracoabdominal region consistent with prior repair of a hiatal hernia .
    OUTPUT:
    
1 . Opacification at the left lung base may represent atelectasis in this postoperative patient , but pneumonia can not be excluded in the appropriate clinical context . 2 . Stable appearance status post cardiac surgery .