After a head-on motor vehicle collision at high speed, a patient has a widened mediastinum but is asymptomatic. What is the next best diagnostic test to evaluate for a potential aortic injury?

• A. Spiral CT scan
• B. Transesophageal echocardiography
• C. Chest X-ray
• D. MRI aortic angiography

Answer: (D)

In this scenario, the priority is to definitively assess the thoracic aorta in a patient who is hemodynamically stable after blunt chest trauma. MRI aortic angiography provides highly accurate, noninvasive visualization of the aorta with excellent soft-tissue contrast and multiplanar capability, allowing precise characterization of an aortic injury (intimal tear, pseudoaneurysm, or transection) while avoiding ionizing radiation. This makes it a strong choice when the patient is stable and when detailed anatomy and full aorta evaluation are desired, provided there are no contraindications to MRI or gadolinium and the center has the capability to perform it promptly. While CT angiography is faster and more commonly used in many trauma settings, MRI angiography offers superior contrast resolution and a radiation-free option for definitive assessment before proceeding with definitive management.