Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable AP upright chest radiograph was obtained . Low lung volumes crowd the central pulmonary vasculature . In addition , prominence of the upper lobe vasculature may suggest a mild degree of pulmonary vascular congestion . There is no focal consolidation , effusion or pneumothorax . Aortic arch calcifications are mild . Cardiac and mediastinal contours are normal . There is no pneumoperitoneum .
    OUTPUT:
    
1 . Low lung volumes . There may be mild central pulmonary vascular congestion . 2 . No pneumoperitoneum .