Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Analysis is performed in direct comparison with the next preceding similar chest examination of ___ . The heart size is normal . No configurational abnormality is seen . The thoracic aorta and mediastinal structures are unremarkable . The pulmonary vasculature is normal . No signs of acute or chronic parenchymal infiltrates are present and the lateral and posterior pleural sinuses are free . No pneumothorax in apical area . The skeletal structure is grossly unremarkable .
    OUTPUT:
    
No evidence of active or latent tuberculosis infection in patient with history of positive PPD . Unchanged chest findings since preceding examination of ___ .