Imaging description

A four-year-old girl initially presented with a heart murmur at age 1, which was thought to be benign. On a routine physical examination at three years of age, she was found to have an elevated systolic blood pressure of 125 mmHg. An echocardiogram was performed and coarctation of the aorta was identified. Preoperative MRI of the chest was performed including an MRA (Fig. 28.1a) showing focal narrowing of the distal arch and hypoplasia with some tortuosity of the descending thoracic aorta. 4D flow phase-contrast MRI (Fig. 28.1b, c, d) showed flow acceleration at the site of focal narrowing as well as increased net flow along the course of the aorta, indicating collateral filling through intercostal arteries. Peak velocities exceeded 360 cm/s, corresponding to a pressure gradient over 50 mmHg.

Importance

Aortic coarctation (Fig. 28.1) and interrupted aortic arch (IAA) (Fig. 28.2) lie along a spectrum of congenital abnormalities of the aortic arch. Aortic coarctation is defined by the presence of flow-limiting stenosis in the aortic arch and is generally classified into three types: preductal, ductal, and postductal. There is most commonly focal narrowing in the proximal descending aorta at the site of the ductus arteriosus/ligamentum arteriosum with post-stenotic aortic and sometimes proximal arch and/or great vessel dilatation. The proximal arch may also be involved in the coarctation to a varying extent, most often manifesting as diffuse hypoplasia in the infantile type of coarctation.