Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were provided . There is a retrocardiac opacity which contains small amounts of gas likely representing a small hiatal hernia . No focal consolidation in the lungs . No effusion or pneumothorax . Cardiomediastinal silhouette appears stable . Bony structures are intact .
    OUTPUT:
    
Small hiatal hernia . Otherwise , normal .