Abdominal Vascular Duplex Exams Flashcards

After endovascular aortic aneurysm repair (EVAR), which duplex finding indicates a Type II endoleak?

Answer: Flow within the aneurysm sac originating from a patent lumbar or inferior mesenteric artery

A Type II endoleak is characterized by retrograde flow into the aneurysm sac from branch vessels such as lumbar arteries or the IMA.

The hepatic artery normally demonstrates which type of Doppler waveform?

Answer: Low-resistance with continuous antegrade diastolic flow

The hepatic artery supplies a low-resistance organ and shows continuous forward diastolic flow, reflecting constant hepatic metabolic demand.

Which velocity criterion is most widely accepted for diagnosing ≥60% renal artery stenosis on duplex ultrasound?

Answer: Renal artery PSV ≥180–200 cm/s with RAR ≥3.5

Most laboratories use a renal artery PSV of 180–200 cm/s combined with an RAR ≥3.5 as the threshold for hemodynamically significant (≥60%) stenosis.

During evaluation of the mesenteric vessels, the superior mesenteric artery (SMA) waveform changes significantly with eating. Postprandially, the SMA waveform should demonstrate:

Answer: Increased diastolic flow and decreased pulsatility index reflecting reduced resistance

After eating, intestinal blood demand rises, causing mesenteric vasodilation and a drop in resistance, which increases diastolic flow and lowers the pulsatility index.

Which accessory renal artery location creates the greatest diagnostic challenge during duplex scanning?

Answer: Lower pole accessory renal artery arising from the distal aorta or iliac artery

Lower pole accessory renal arteries arising distally are most likely to be missed on duplex because their origin lies outside the typical scanning zone for renal arteries.

In the evaluation of a renal transplant by duplex ultrasound, which finding raises the concern for renal vein thrombosis?

Answer: Reversed diastolic flow (below baseline) in the intrarenal arteries

Renal vein thrombosis markedly raises downstream venous pressure, causing reversal of diastolic arterial flow as a characteristic duplex sign.

What is the primary purpose of performing a celiac axis duplex examination during both inspiration and expiration?

Answer: To distinguish extrinsic compression by the median arcuate ligament from intrinsic atherosclerotic stenosis

Median arcuate ligament compression of the celiac artery typically worsens during expiration and improves with inspiration, distinguishing it from fixed atherosclerotic disease.