Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate mild leftward rotation , somewhat limiting evaluation . The lungs are clear . Opacity in the right lower lung likely reflects overlying breast shadow . There is unchanged narrowing of the cervical trachea . The pleural surfaces are normal . The cardiac silhouette and hila are unremarkable . A vagal nerve stimulator unit implanted in the left chest is similar appearing .
    OUTPUT:
    
No acute chest abnormality .