Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is borderline enlarged . The mediastinal and hilar contours are stable and unremarkable . There is no pleural effusion or pneumothorax . The lungs are clear besides left lower lung atelectasis . No subdiaphragmatic free air is noted .
    OUTPUT:
    
No acute cardiopulmonary process .