Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . The heart is of normal size with normal cardiomediastinal contours . Lungs are clear . No pleural effusion or pneumothorax . Retrocardiac opacity containing air is compatible with a moderate sized hiatal hernia seen on ___ . No radiopaque foreign body .
    OUTPUT:
    
Moderate hiatal hernia , which could predispose the patient to aspiration . No evidence for acute cardiopulmonary process .