Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is atelectasis at the left lung base . No focal consolidation is identified . The cardiomediastinal silhouette and hilar contours are stable given differences in patient positioning . There is no pleural effusion or pneumothorax . Degenerative changes are noted in the cervical spine as well as the bilateral shoulders . Calcifications of the aortic arch and the tracheobronchial tree are again noted .
    OUTPUT:
    
Atelectasis at the left lung base . No focal consolidation .