A traumatic injury near the ligamentum arteriosum may result in which imaging finding?

• A. Fractures of ribs 3-6
• B. Kerley-A lines
• C. Fractures of ribs 10-11
• D. Widened mediastinum on chest X-ray

Answer: (D)

Blunt trauma to the chest can injure the aorta at the isthmus, just distal to the ligamentum arteriosum, which is a common site for traumatic aortic injury due to deceleration. This area’s vulnerability leads to mediastinal bleeding and a widening of the mediastinum on chest radiography—the classic imaging sign of this injury. While you may see other subtle clues like an abnormal aortic contour or a left apical cap, the widened mediastinum is the key finding pointing toward a traumatic aortic injury. Rib fractures or Kerley lines reflect different chest conditions and aren’t specifically indicative of this aortic problem. If mediastinal widening is observed, CT angiography is typically used to confirm the injury.