Pitfall in the ultrasound scanning of the abdominal aorta

Jonathan Dube, University College Dublin, University Hospital Kerry


Atherosclerosis is a potential cause of abdominal aortic stenosis, which is typically linked to hypertension. The abdominal aortic atheroma, which is frequently calcified, appears echogenic with posterior acoustic shadowing. Some studies have identified that a significant portion of the abdominal aorta is inadequately visualised during the ultrasound scan due to elevated BMI or bowel gas.

Patient background

A 49-year-old female presented with left iliac fossa pain radiating to the flanks. The patient was a smoker. The patient had a raised white blood cell count of 13.7 and was hypertensive. In the previous ultrasound examination, it was concluded that the aorta was obscured by bowel gas. However, a subsequent Computed Tomography scan showed atherosclerosis with calcified plaques and stenosis of the infrarenal aorta. An ultrasound examination was ordered for further evaluation of the abdominal aorta.

Ultrasound findings

Atheroma and calcification were noted from the origin of the superior mesenteric artery down to the distal abdominal aorta. High-grade stenosis greater than 90% with increased peak systolic velocity of 258 cm/s and 305 cm/s were observed in the mid-abdominal aorta and superior mesenteric junction respectively. Both common iliac arteries appeared atheromatous with increased peak systolic velocities of 157 and 140 cm/s respectively. Referral to the vascular surgeon was organised.


The calcified aortic atheroma has a strong echogenic appearance with posterior acoustic shadowing, simulating the presence of bowel gas. Furthermore, Doppler ultrasound may assist to assess the vascular lumen and the presence of atherosclerotic plaques which may result in abdominal aortic stenosis, hence evaluating the haemodynamic parameters. With the advancements in contrast-enhanced sonography techniques, microbubbles can now clearly display the adventitia that feeds atherosclerotic arteries and intraplaque neovascularisation.


Before concluding that the aorta cannot be demonstrated, it is crucial to distinguish between posterior acoustic shadowing and bowel gas.

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