Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is moderately enlarged , taking into account low lung volumes , which accentuates the heart size and pulmonary vasculature . The mediastinum is widened . Hilar contours are unremarkable . Lungs are clear . Pleural surfaces are clear without effusion or pneumothorax . No fracture is identified .
    OUTPUT:
    
1 . Widened mediastinum may be secondary to fat deposition , but given the mechanism of injury , aortic injury is not excluded and further evaluation with CT is warranted . 2 . No definite fracture .