Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are somewhat low lung volumes , but the lungs are clear . There is no pleural effusion or pneumothorax . A large hiatal hernia is noted , similar to prior exams . The cardiomediastinal silhouette is mildly enlarged , similar to prior exam .
    OUTPUT:
    
1 . No acute cardiopulmonary process . 2 . Large hiatal hernia , similar prior exam .