ACR Appropriateness Criteria for Suspected Aortic Injury

Axial contrast-enhanced CT image shows a pseudoaneurysm (arrow), intimal flap and periaortic hematoma of the proximal descending thoracic aorta in a patient experienced severe blunt chest trauma.

A newly revised American College of Radiology (ACR)'s Appropriateness Criteria for blunt chest trauma - suspected aortic injury has been published in March 2012 in the journal Emergency Radiology, summary and useful points are provided below

• Chest x-ray remains an initial screening examination in patients who has sustained blunt chest trauma
• In the appropriate clinical setting and with a CXR demonstrating mediastinal widening or other signs of mediastinal hemorrhage, thoracic aortography or helical chest CT is indicated
• CTA is emerging as a very sensitive and specific examination for aortic injury and has replaced aortography in many trauma centers

Useful Points

• Mediastinal widening has been defined as a transverse diameter of 8 cm from the left side of aortic arch to the right margin of the mediastinum (even on AP portable CXR)
• Mediastinal widening is 90% sensitive but 10% specific for aortic injury
• Approx 7% of patients with aortic injury have normal initial CXR
• If no mediastinal hematoma seen on CT, probability of significant aortic injury is very low

Reference

Demehri S, et al. ACR Appropriateness Criteria blunt chest trauma--suspected aortic injury. Emerg Radiol 2012 (published online: 18 Mar 2012)