Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post sternotomy . The cardiac , mediastinal and hilar contours appear unchanged . There is improvement in lung volumes with better aeration of the lung bases . There is no definite pleural effusion or pneumothorax although given technique small residual persistent pleural effusions would to be difficult to detect .
    OUTPUT:
    
No evidence of acute cardiopulmonary disease .