Retrotracheal Triangle

The retrotracheal (RT) triangle, also known as the Raider triangle, is seen on the lateral chest radiograph and is bordered anteriorly by the posterior wall of the trachea, posteriorly by the upper thoracic vertebrae and inferiorly by the distal portion of the aortic arch. On frontal radiographs, the triangle is bordered superiorly by the thoracic inlet, laterally by the manubrial borders, and inferiorly by the aortic arch.

A number of processes may manifest as abnormalities of the Raider triangle, including:

• Acquired vascular anomalies: Aortic aneurysm, pseudoaneurysm, transection.
• Congenital vascular anomalies: Aberrant right subclavian artery (with left aortic arch), aberrant left subclavian artery (with a right aortic arch), double aortic arch.
• Esophageal abnormalities: Esophageal atresia, Zenker diverticulum, achalasia, carcinoma.
• Mediastinal masses: Neoplasm, hemorrhage, lymphadenopathy (shown above), lymphatic malformation, abscess.
• Thyroid masses: Intrathoracic goiter.

References

Franquet T, Erasmus JJ, Giménez A, Rossi S, Prats R. The retrotracheal space: normal anatomic and pathologic appearances. Radiographics. 2002 Oct;22 Spec No:S231-46.