Unfolded aorta


  • An 84 years old man.
  • Admitted for acute urinary retention
  • Subsequently diagnosed Benign prostatic hypertrophy
  • Noted abnormal chest radiograph (incidental finding).
Chest radiograph frontal view

Radiographic findings:

  • There is widening of mediastinum. The mediastinum measured at aortic arch level (double-head arrow) is 9.9 cm.
  • There is a well-defined bulge at the right mediastinal outline (yellow arrow) which shows continuation with the aortic arch.
  • No lung lesion seen. No pleural effusion or pneumothorax.
  • Heart is not enlarged. No bone changes.
CT thorax, axial plane soft tissue window post contrast.

CT scan findings:

  • The aortic root measures about 3.6 cm, while the aortic arch and descending aorta measuring about 2.7 cm and about 2.8 cm respectively.
  • No aortic aneurysm or dissection is demonstrated.
  • No intimal flap or thrombus seen.
  • The heart is not enlarged. No pericardial effusion.

Diagnosis: Mediastinal widening caused by unfolded aorta.


  • Unfolded aorta is not a pathological condition but can be mistaken for thoracic aneurysm.
  • It is a common x-ray finding in elderly patient.
  • It is seen as widened mediastinum on frontal chest radiograph. Normal mediastinal width should be <8cm at the level of aortic arch.
  • Also descibed as “opened up” appearance of the aortic arch.
  • This is due to discrepancy in the growth of ascending aorta with age
Author: radhianahassan