Coarctation of Aorta

  • Etiology: Congenital
  • Imaging CXR:
    — 3 sign is prestenotic dilation of ascending aorta, coarctation, post-stenotic dilation of descending aorta
    — Rib notching due to shunting of blood from subclavian artery to internal thoracic artery to intercostal arteries to descending aorta
    — First 2 ribs spared from notching because they are supplied from costocervical trunk
    — It takes 10 years before the collateral intercostal arteries are dilated enough for the rib notching to be visible
  • Imaging UpperGI: Reverse 3 sign is hypoplastic aortic knob with dilated post stenotic segment
  • Imaging CT:
    — Infantile (diffuse) type: Preductal long segment narrowing from innominate artery to ductus arteriosus
    — Adult (focal) type: Ductal or postductal short segment narrowing
  • DDX:
  • Complications:
  • Treatment:
  • Clinical:
    — Infantile (diffuse) type is left sided obstructive lesion so neonatal ductal dependent for collateral flow
    — Adult (focal) type is most common form and presents later due to presence of collaterals

Radiology Cases of Coarctation of Aorta

Radiology Cases of Preductal Coarctation of Aorta

3D CT of preductal coarctation of the aorta
3D CT with contrast of the aorta viewed posteriorly (left) shows diffuse narrowing of the aortic arch until its junction with the descending aorta. 3D CT viewed anteriorly (right) shows a huge patent ductus arteriosus joining into the descending aorta.

Radiology Cases of Postductal Coarctation of Aorta

CXR of coarctation of aorta
CXR AP shows a 3 sign in the region of the aortic arch and bilateral rib notching.
CT of post-ductal coarctation of the aorta
Sagittal CT (above left) and 3D CT (above right) with contrast of the chest show significant narrowing of the proximal descending aorta distal to the origin of the left subclavian artery. Anterior 3D CT (below left) shows dilated bilateral collateral internal mammary arteries and posterior 3D CT (below right) shows dilated bilateral collateral 3rd-8th intercostal arteries.
3DCT of post ductal coarctation of the aorta
3D CT with contrast of the chest shows a significant focal narrowing of the proximal descending aorta distal to the origin of the left subclavian artery.