Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest . Linear opacity identified at the left lung base is most likely atelectasis versus scarring . The lungs are otherwise clear . The cardiomediastinal silhouette is stable . Post-operative changes with median sternotomy and mediastinal clips are again noted . No acute osseous abnormality is identified .
    OUTPUT:
    
No acute cardiopulmonary process .