Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs were obtained . Lung volumes are low , but the lungs are clear . The cardiomediastinal silhouette , hilar contours , and pleural surfaces are normal . There is no pleural effusion or pneumothorax . Osseous structures are unremarkable . No free air is seen under the hemidiaphragms .
    OUTPUT:
    
No evidence of acute cardiopulmonary process .