Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly low . The heart is top normal . The mediastinal and hilar contours are unremarkable . There is calcification of aortic arch . There is no pleural effusion or pneumothorax . There is no pulmonary edema .
    OUTPUT:
    
Slightly low lung volumes . No convincing evidence of pneumonia . No pulmonary edema .