Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . The cardiomediastinal silhouette is stable . Relatively linear left base retrocardiac opacity most likely represents atelectasis . No definite focal consolidation is seen . There is no pleural effusion or pneumothorax . Degenerative changes are seen at the left shoulder and left acromioclavicular joints .
    OUTPUT:
    
No acute cardiopulmonary process .