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

Treatment

• Usually unnecessary unless diverticulum is greater than 3 cm

Prognosis

• No fatal sequelae usually
• Rare formation of larger aneurysm

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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