Dissecting aneurism of the abdominal aorta. Three-dimensional computed tomographic CT) scan reconstruction of a dissecting aneurism of the sub-renal abdominal aorta. In this type of aneurysm, the inner wall of the aorta (intima) detaches from the outter wall (media). The blood invades the created space and generate a bulge that can break. The aneurysm is visible as a longitudinal furrow that extends from the renal arteries to the common iliac arteries.