Figure 15

Sites of measurement. AS = aortic sinus; STJ = sinotubular junction; AA = ascending aorta; BCA = proximal to the origin of the brachiocephalic artery; T1 = first transverse segment; T2 = second transverse segment; IR = isthmic region; DA = descending aorta; D = thoracoabdominal aorta at the level of the diaphragm.