What are we looking for?
- Aortic Abdominal Aneurysm (AAA)
- Aortic Dissection can potentially be seen, but identifying a dissection is not the clinical question when performing an US scan of the aorta
Which probe do we use?
- Curvilinear Probe
How do we find the aorta and identify its vessels?
- Look for the vertebral body as a landmark! The aorta lies above it in the short axis.
- “Seagull Sign” – the hepatic and splenic arteries can be seen in the short axis of the proximal aorta in the epigastric region.
- Long axis aorta (sagittal plane) – the Superior Mesenteric Artery (SMA) can be seen rising from the aorta in long axis.
- “Mantel Clock Sign” – short axis proximal aorta with SMA and splenic vein overlying it superiorly.
- Iliac Bifurcation- Trace the lower aorta through its bifurcation into the iliac arteries
What is normal vs. abnormal?
- Measure the aorta along it’s course through the abdomen in short axis. > 3 cm from outer edge to outer edge is considered abnormal and concerning for AAA.
- Look for dissection flaps and intramural thrombus!
References:
https://coreem.net/core/abdominal-aortic-ultrasound/ https://www.acep.org/sonoguide/basic/aorta https://radiologykey.com/abdominal-aorta-5/
