Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is normal . The aorta is tortuous . Atherosclerotic calcifications at the aortic knob are present . Mediastinal and hilar contours are otherwise unremarkable . Pulmonary vasculature is not engorged . Patchy opacity in the left lung base likely reflects atelectasis . No focal consolidation , pleural effusion or pneumothorax is demonstrated . Remote left - sided rib fractures are present . Partially imaged are posterior fusion rods spanning the thoracolumbar spine . No subdiaphragmatic free air is present .
    OUTPUT:
    
No subdiaphragmatic free air . Minimal atelectasis in the left lung base .