Fig.2: Axial CT with IV contrast shows a large periaortic hematoma (stars) displacing the NG tube (arrowhead) to the right.
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)
