Figure 5b. Dissecting thoracoabdominal aortic aneurysm in a 58-year-old woman. (a, b) On oblique coronal MPR images from MR angiography (a) and CT angiography (b), the artery of Adamkiewicz (arrow) is seen to originate from the left 11th radiculomedullary artery (arrowhead) at the level of the left 11th intercostal artery. (c) Axial MPR image from CT angiography performed at the level of the 11th intercostal artery shows the radiculomedullary artery (arrowhead). The proximal portion of the left 11th intercostal artery is not visualized. (d, e) Oblique axial MPR images from MR angiography demonstrate a patent left 10th intercostal artery (d) and occlusion of the proximal portion of the left 11th intercostal artery (arrow in e). (f, g) Oblique sagittal (f) and coronal (g) MPR images from MR angiography show occlusion of the proximal portion of the left 11th intercostal artery (arrow in f) and origination of the collateral artery from the muscular branch of the left 10th intercostal artery (arrowhead).