Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lower lung volumes are seen on the current exam . There is secondary crowding of the bronchovascular markings particularly on the lateral . Linear bibasilar opacities are most likely atelectasis . There is no large effusion . The cardiomediastinal silhouette is grossly unchanged . No acute osseous abnormalities identified . Bold posterior left rib fracture is identified .
    OUTPUT:
    
Bibasilar opacities are likely atelectasis due to lower lung volumes noting that infection can not be excluded .