Use the vertebral body as your landmark. The aorta sits above this with the IVC on the left of screen. Start proximal and slide distally until the aorta bifurcates.
<3cm is normal for AA.
<1.5 normal for iliac arteries.
Abdominal aortic aneurysm (AAA)
AAA (4.6cm outer wall to outer wall) with intraluminal thrombus
