Radiographic Findings in Aortic Trauma

The most reliable signs of mediastinal hemorrhage on supine radiographs are an abnormality of the aortic contour or the presence of one or more of the following:

• Transverse mediastinal width > 8 cm just above the aortic knob
• Apical cap sign
• Widening (> 5 mm) of the right paratracheal stripe
• Deviation of the nasogastnic tube to the right of the T4 spinous process

We can achieve a sensitivity of 93% and specificity of 60% for ruptured aorta in a trauma patient with evidence of mediastinal hemorrhage if at least one of these two signs is present:

• Deviation of the nasogastnic tube to the right of the T4 spinous process
• Widening (> 5 mm) of the right paratracheal stripe

When both the nasogastric tube and trachea are deviated to the right, we have a 96% chance of having an aortic rupture, and some feel that this is a very specific sign for aortic rupture.

Displacement of the left mainstem bronchus inferiorly and to the right can be seen with mediastinal hemorrhage and has been advocated as a specific sign of aortic isthmus rupture

Signs such as an increased (> 0.25) mediastinal width to chest width ratio, tracheal deviation to the right of midline, left hemothorax without associated rib fracture, widening of the paraspinal lines, and aortopulmonary window opacification do not reliably separate patients with mediastinal hemorrhage from normal.

References

Woodring JH, Loh FK, Kryscio RJ. Mediastinal hemorrhage: an evaluation of radiographic manifestations. Radiology. 1984 Apr;151(1):15-21.