Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Large intra-abdominal free air . Lung volumes are low without focal consolidation . Relative crowding of the interstitial markings and bronchovascular structures likely secondary to low lung volumes . Cardiomediastinal silhouette is normal . There is no pneumothorax or pleural effusion . No acute osseous abnormalities seen .
    OUTPUT:
    
Large intra-abdominal free air , likely secondary to recent surgery . No evidence of pneumonia .