mrcem2-2117

A 42-year-old woman was in a car crash where her vehicle collided with a wall at a high speed. She was not wearing a seatbelt and was thrown forward onto the steering wheel. She has bruising on her front chest wall and is experiencing chest pain. The chest X-ray taken in the emergency room shows signs of a traumatic aortic injury.

Which of the following chest X-ray findings is most indicative of this injury?