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 study of ___ . The heart size remains unchanged and is within normal limits . Unaltered normal appearance of thoracic aorta and mediastinal structures . The pulmonary vasculature is not congested . No signs of acute or chronic parenchymal infiltrates are present and the lateral and posterior pleural sinuses are free . No pneumothorax in apical area . Skeletal structures of the thorax remain unremarkable .
    OUTPUT:
    
Stable chest findings within normal limits . No radiographic evidence of new infiltrates or skeletal abnormalities , no mediastinal masses are identified .