대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Pseudocoarctation of Aorta

Radiologic Findings

Chest PA shows a mass in the left superior mediastinum.

Contrast-enhanced chest CT reveals a vascular mass that is contiguous with the aorta.

Aortic arch is tortuous, buckled, and is located high in the mediastinum.

Dilated, tortuous branching vessel is seen in the medial aspect of vascular mass, considered dilated left subclavian artery.

MRA shows a kink in the course of the aorta without actual narrowing, which is consistent with pseudocoarctation of aorta. The abnormally located, dilated left subclavian artery is well visualized.

Brief Review

Pseudocoarctation of the aorta is relatively rare congenital anomaly consisting of redundancy of the aortic arch without significant obstruction.

Unlike coarctation, however, there is no obstruction of blood flow and therefore little or no demonstrable pressure gradient and no evidence of collateral circulation.

Pseudocoarctation is usually asymptomatic, but they often are found to have high blood pressure. A systolic murmur also may be present. Anomalies associated with pseudocoarctation include bicuspid aortic valve, patent ductus arteriosus, ventricular septal defect, corrected transposition, aneurysm of sinus of Valsalva, aortic stenosis, Turner syndrome, megacalyces, coexistent true coarctation, and dilatation and tortuosity of the left subclavian artery.

Chest PA shows a typical appearance. A homogeneous left upper, mediastinal, soft tissue mass is located above and behind what appears to be a normal but often low-lying the aortic knob. The mass is composed of the redundant segment of the aorta forming a pseudoaortic knuckle end on.

CT findings in pseduocoarctation of the aorta are as follows;
1) demonstration that the abnormal mass in the mediastinum is part of the aorta;
2) an unusual aortic arch high in the mediastinum;
3) visualization of the isthmic portion of the descending thoracic aorta not adjacent of the spine but rather ventral to it, and surrounded by aerated lung;
4) more caudal origin of the subclavian artery.

Angiography is diagnostic in those cases where the entire course of the aorta is clearly outlined. There is anterior and medial displacement of the distal aortic arch with a kink in the posterior and lateral margins of the aorta. The lumen of the aorta at the level of the kink may or may not be narrowed. If any narrowing appears to be present, it is not hemodynamically significant since collateral circulation is absent. MRA would be promising technique that replaces the role of angiography.

References

1. Taneja K, Kawlra S, Sharma S, Rajani M. Pseudocoarctation of the aorta: complementary findings on plain film radiography, CT, DSA, and MRA. Cardiovasc Intervent Radiology 1998; 21:439-41

2. Munjal AK, Rose WS, Williams G. Magnetic resonance imaging of pseudocoarctation of aorta: a case report. J thorac imaging 1994; 9: 88-91.

Keywords

Vascular, Congenital,