RadioGraphics 2003; 23:S79-S91.
Sebastia C, Quiroga S, Boye R, Perez-Lafuente M, Castella E, Alvarez-Castills A.
Aortic stenosis, or narrowing of the aortic lumen, has many causes. It may originate in coarctation or pseudocoarctation of the aorta, midaor-tic dysplastic syndrome, atherosclerosis, Takayasu arteritis, aortic dissection, or various intraaortic and periaortic diseases or as a result of aortic surgical repair. The impedance of blood flow through the ste-notic segment may lead to the development of various collateral arterial pathways, according to the location of stenosis. Aortography is the standard technique for evaluating aortic stenosis; however, helical computed tomography (CT), particularly multisection CT, may provide additional information or in some cases may be used instead of arteriography. Multisection CT can depict the aorta and thoracoab-dominal collateral pathways in less than 1 minute and provide high-quality arterial-phase imaging data suitable for multiple two-dimensional and three-dimensional reformations. To produce a useful differential diagnosis, the imaging specialist must be able to recognize the type of stenosis and the configuration of collateral circulatory pathways.