Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung is well inflated , without consolidation or nodules . Cardiomediastinal silhouette is normal . There is no pneumothorax or pleural effusion . Large right subdiaphragmatic air collection is likely related to recent abdominal surgery .
    OUTPUT:
    
Pneumoperitoneum , but no sign of acute cardiopulmonary process .