Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is top - normal . Atherosclerotic calcifications are noted in the aortic knob . Hilar contours are normal . Lung volumes are low with probable left base atelectasis . Lungs are otherwise clear . Pleural surfaces are clear without effusion or pneumothorax . There is no suggestion of abdominal free air .
    OUTPUT:
    
No acute cardiopulmonary abnormality . No evidence of pneumoperitoneum .