Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiograph demonstrates unremarkable cardiomediastinal and hilar contours . Minimal streaky opacifications in left lung base likely reflect atelectasis given left hemidiaphragm elevation . No pleural effusion or pneumothorax evident . No pneumoperitoneum identified . Multilevel degenerative changes are detected .
    OUTPUT:
    
Normal chest radiograph . No pneumoperitoneum .