Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph demonstrate clear lungs . When compared to prior radiograph dated ___ , there is been no interval change . Cardiomediastinal hilar contours are within normal limits . Linear opacity within the left lung base is thought to reflect atelectasis . No acute osseous abnormalities identified .
    OUTPUT:
    
No acute intrathoracic abnormality .