Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest . No prior . Linear opacity at the left lung base is most suggestive of atelectasis as it is not well seen on the lateral . Elsewhere , the lungs are clear , there is no effusion . Cardiomediastinal silhouette is normal . Osseous and soft tissue structures are unremarkable .
    OUTPUT:
    
No acute cardiopulmonary process .