Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single AP upright portable view of the chest was obtained . There are relatively low lung volumes . No definite focal consolidation is seen . There is no pleural effusion or pneumothorax . The cardiac silhouette appears mildly enlarged , likely accentuated by AP , and portable technique . The aortic knob is calcified .
    OUTPUT:
    
No definite acute cardiopulmonary process .