Imaging description

Coarctation of the aorta is a congenital defect thought to result from incorporation of tissue from the ductus arteriosus into the wall of the aorta. Regression of the ductal tissue results in focal narrowing and kinking of the proximal descending aorta [1, 2]. If the obstruction is severe enough, blood flow to the lower body may become dependent on collateral flow, usually via the intercostal or internal mammary arteries (Figure 47.1). Dilatation of the intercostal arteries can result in erosion of the inferior aspect of the ribs and the classic chest radiographic finding of rib notching [3]. Pseudocoarctation refers to mild cases of narrowing without significant collateral flow (Figure 47.2). The pressure gradient across the narrowed segment in pseudocoarctation is <25 mmHg by definition [4].

Importance

Coarctation of the aorta is seen in association with a number of syndromes and intracardiac congenital defects. In adults, coarctation can be associated with aortic or intercostal aneurysm formation, aortic dissection, and intracranial berry aneurysm formation [2].