Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are compared to previous exam from ___ . Linear opacity at the left lung base suggestive of atelectasis . Elsewhere , the lungs are clear . There is no pneumothorax . Cardiomediastinal silhouette is unchanged given lower lung volumes . There is no visualized displaced rib fracture on this non-dedicated exam .
    OUTPUT:
    
No visualized displaced rib fracture . If desired , dedicated rib series can be performed .