Coarctation and Pseudocoarctation of the Aorta

Coarctation of the aorta is a rare lesion in adults and is not likely to be discovered incidentally during chest CT for other indications. Magnetic resonance

Figure 3 Right aortic arch with aberrant left subclavian artery. (A) Contrast-enhanced CT through upper chest in a patient with dysphagia shows a right aortic arch with an aberrant left subclavian artery (arrow) coursing toward the left in a retroesopha-geal location. (B) Scan through the apices shows the normal position of the left subcla-vian artery (arrow).

Figure 3 Right aortic arch with aberrant left subclavian artery. (A) Contrast-enhanced CT through upper chest in a patient with dysphagia shows a right aortic arch with an aberrant left subclavian artery (arrow) coursing toward the left in a retroesopha-geal location. (B) Scan through the apices shows the normal position of the left subcla-vian artery (arrow).

imaging is the preferred method for evaluation of coarctation. The coarctation is almost always just distal to the origin of the left subclavian artery although lower thoracic and abdominal coarctations occur. The area of narrowing may be quite discrete and easily missed on axial images, but should be apparent on reconstructed sagittal images. Dilatation of the descending aorta and left subclavian artery may be the only clues to the presence of coarctation on the axial images. Dilatation of the ascending aorta is not uncommon and may result from systemic hypertension or a stenotic aortic valve, the latter related to the high incidence of bicuspid aortic valve in patients with aortic coarctation.

Pseudocoarctation of the aorta is caused by kinking or folding of the proximal portion of the descending aorta and frequently results in a mass on the frontal chest radiograph. The diagnosis can be suspected from the lateral chest radiograph where the actual kink is sometimes visible. Because CT is the primary modality for evaluation of mediastinal masses, one is more likely to encounter a patient with pseudocoarctation than with coarctation. Pseudoco-arctation is thought by some to be a form fruste of coarctation, in part because it also has a high association with bicuspid aortic valve and an increased incidence in Turner's and Noonan's syndromes. By definition there is absent or a trivial pressure gradient across the pseudocoarctation and surgical repair is rarely necessary. On axial CT images one sees a very dilated proximal descending aorta that usually extends higher than normal. The left subclavian artery may arise from either above or below the kink. Sagittal reconstructions nicely demonstrate the folded aorta and great vessel origins.

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Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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