Traumatic Aortic Injury

Fig.3: Axial CT at the level below the arch demonstrates a pseudoaneurysm (red arrow) anterior to the true lumen (red arrowhead). Hematoma (stars) and NG tube (yellow arrowhead)

Radiographic Findings
- Widening of superior mediastinum (subjective 'eyeball' estimation)
- Blurring of aortic contour
- Deviation of nasogastric tube to the right
- Normal - not common but x-ray can be normal if there is no or minimal periaortic hematoma (Normal chest radiograph does not exclude TAI in a trauma patient with suspicious mechanism)

CT Findings
- Direct signs: Pseudoaneurysm, intimal flap, irregularity of aortic wall, pseudocoarctation, thrombus with in the wall
- Indirect sign: Periaortic hematoma (not isolated anterior mediastinal hematoma)

Do We Need Aortography?
- Studies of MDCT (16- and 64-MDCT) showed accuracy of near 100% using surgery or follow-up CT as standard references
- When a direct sign is present, TAI can be diagnosed confidently without aortography
- Aortography can be reserved for equivocal cases, evaluation of aortic branch vessels and endovascular therapy

References:
1. Kaewlai, et al. MDCT of blunt thoracic trauma. Radiographics 2008 (October)
2. Steenburg, et al. Acute traumatic thoracic aortic injuries: experience with 64-MDCT. AJR 2008 (November)