Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is top - normal with mild unfolding of the thoracic aorta . Hilar contours are unremarkable . Lung volumes are low accentuating the cardiac silhouette and pulmonary vasculature . There is mild left base atelectasis . Lungs are otherwise clear . Pleural surfaces are clear without effusion pneumothorax .
    OUTPUT:
    
No acute cardiopulmonary abnormality .