Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung hyperinflation . The lungs are clear . No pleural effusion or pneumothorax . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
No acute cardiopulmonary process . No nodules noted within the limitations of plain radiograph . Lung hyperinflation may be seen in COPD .