Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Suture denotes prior surgery in the left mid and upper lung . There is no effusion . The cardiac silhouette is normal . The aortic arch is mildly dilated , evaluated by subsequent CTA . Opacity in the low posterior lung on the lateral view only is not confirmed by CT .
    OUTPUT:
    
No acute chest pathology .