Learning Radiology xray montage

Ductus Diverticulum
Ductus Bump

General Considerations

  • Occurs on the anterior and medial surface of the aortic isthmus at the site of the ductus arteriosus
  • Found in about 9% of adults on aortography
  • More commonly found in children

Clinical Findings

  • None

Imaging Findings

  • Best imaged with contrast-enhanced Ct with 3D reconstruction or MRI
    • On CT, best visualized on sagittal oblique reconstructed images
  • Diverticulum has smooth and uninterrupted margins
  • Obtuse angles formed by the ductus diverticulum and the aortic wall 
  • More atypically, a ductus diverticulum may have a steeper slope on its cephalad margin and a gentle slope on its inferior margin

Differential Diagnosis

  • Pseudoaneurysm (forms acute angle with aorta)
    • On aortography, will demonstrate an intimal flap and/or
    • Delayed clearance of contrast
  • Penetrating ulcer
  • Aortic dissection


  • Usually unnecessary unless diverticulum is greater than 3 cm


  • No fatal sequelae usually
  • Rare formation of larger aneurysm

Ductus Diverticulum

Ductus Diverticulum. The chest radiograph demonstrates a rim-calcified lesion adjacent to the aortic knob (white arrow). CT reconstruction demonstrates a projection from the anterior wall of the aorta at the level of the ligamentum arteriosus (blue arrow) The diverticulum is atypical in that it has a steeper angle cephalad.
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