Aorta Exam

Indications

  • Flank, back, groin, abdominal, or chest pain
  • Hypertension, hypotension
  • Pulsatile abdominal mass
  • Cardiac arrest
  • Elderly (age >65) with history of smoking, hypertension

Acquisition

The Views

  • Aorta Short Axis
  • Aorta Long Axis
  • Celiac Trunk
  • Superior Mesenteric Artery (SMA)
  • Renal Arteries
  • Bifurfaction of Iliac Arteries

The Patient

  • Supine

The Probe

  • Phased Array
  • Curvilinear

Aorta Short Axis

The Moves

Start subxiphoid and identify the Aorta and the IVC

Transverse plane with leading edge towards patient's RIGHT.

Identify the vertebral body in the transverse plane.

The IVC will be to the right of the Aorta and have resipratory variability

The Aorta sits ontop of the verterbral body or slightly to the left

The First Branch you will encouter will be the Celiac Trunk

Normal diameter of the aorta below the renal artery is <23mm (men) and <19mm (women).

Celiac Trunk

the Moves

Rotate back to short axis and move the transducer caudally pushing hard enough to displace bowel gas. Leading edge pointed towards patient's right.

Continue moving caudally. First bifurcation is the celiac trunk; look for the "seagull sign."

Superior Mesenteric Artery (SMA)

Save an image and include the "donut sign," the echogenic area around the SMA that is visible when viewed in the short axis.

The Moves

Continue caudally until the next branch (SMA) is visualized. Leading edge pointed towards patient's right.

Bifurcation of Iliac Arteries

The Moves

Continue caudally until the aorta bifurcates into the iliac arteries, around the level of the umbilicus. Leading edge pointed towards patient's right.

Aorta Long Axis

The Moves

Rotate the transducer. Leading edge pointed towards patient's head.

Rotate the probe until the vessel does not taper at the edges. Vessels should reach from leading edge to receding edge.

Impression and Medical Decision Making

Atherosclerosis

Abdominal Aortic Aneurysm (AAA)

> 30mm in diameter = AAA

Can see evidence of wall thickening & calcifications.

Dissection

Low Sensitivity by High Specificity for dissection. Look for internal flap.

Turn up the gain and look in short and long axis if concenred.

Tips and tricks

  • Use the vertebral body as a landmark. Aorta should sit on top of VB
  • "Milk" the bowel to remove gas from the near field by slow constant pressure
  • Use Pulsed Wave Doppler to differentiate between artery and vein
  • Measure Outer to Outer being careful to include thrombosed region which may appear hypoechoic rather than anechoic
  • Rescue view may be obtained by going to the midaxillary line in either RUQ or LUQ
  • Just because it pulastes does not mean its arterial, veins can appear pulsatile secondary to proximity to artery