Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Other than a small focus of linear atelectasis at the left lung base , the lungs are fully expanded and clear . No pleural abnormalities . Heart size is normal . Cardiomediastinal and hilar silhouettes are normal . No radiographic evidence of rib fractures . There are mild degenerative changes of the thoracic spine .
    OUTPUT:
    
No radiographic evidence of rib fractures or acute bony abnormalities .