RVT Abdominal Vascular Duplex Exams 2 — Questions and Answers
Question 1: Which Doppler waveform characteristic is most consistent with significant celiac artery stenosis?
- Increased peak systolic velocity with post-stenotic turbulence (Correct answer)
- Monophasic low-resistance waveform throughout
- Absent diastolic flow with high pulsatility
- Bidirectional flow at the level of the stenosis
Correct answer: Increased peak systolic velocity with post-stenotic turbulence
Significant celiac artery stenosis produces elevated peak systolic velocity at the stenosis with turbulent, disturbed flow distal to the lesion.
Question 2: During an abdominal aortic duplex exam, the normal infrarenal aorta diameter in an adult male should be less than:
- 2.0 cm
- 3.0 cm (Correct answer)
- 4.0 cm
- 1.5 cm
Correct answer: 3.0 cm
The normal infrarenal aorta diameter is less than 3.0 cm; a diameter of 3.0 cm or greater defines an abdominal aortic aneurysm.
Question 3: A patient presents with postprandial abdominal pain and weight loss. Duplex imaging shows elevated PSV in the superior mesenteric artery. Which additional finding would confirm hemodynamically significant SMA stenosis?
- PSV greater than 275 cm/s (Correct answer)
- EDV less than 10 cm/s
- Resistive index above 0.90
- Retrograde flow in the hepatic artery
Correct answer: PSV greater than 275 cm/s
A PSV exceeding 275 cm/s in the SMA is the established threshold for hemodynamically significant stenosis (≥70%).
Question 4: When performing a renal artery duplex exam, the renal-to-aortic ratio (RAR) is calculated using which measurement?
- Renal artery PSV divided by aortic PSV (Correct answer)
- Renal artery EDV divided by aortic EDV
- Renal artery diameter divided by aortic diameter
- Renal parenchymal velocity divided by renal artery PSV
Correct answer: Renal artery PSV divided by aortic PSV
The RAR is calculated by dividing the highest renal artery PSV by the infrarenal aortic PSV; a ratio ≥3.5 indicates significant stenosis.
Question 5: In abdominal duplex scanning, the 'median arcuate ligament syndrome' most commonly affects which vessel?
- Celiac artery (Correct answer)
- Superior mesenteric artery
- Inferior mesenteric artery
- Right renal artery
Correct answer: Celiac artery
The median arcuate ligament of the diaphragm crosses anteriorly and may compress the celiac artery origin, causing extrinsic stenosis.
Question 6: Which finding on renal duplex ultrasound is most indicative of renal artery occlusion rather than severe stenosis?
- Absence of Doppler signal in the main renal artery with a tardus-parvus waveform in the parenchyma (Correct answer)
- Elevated PSV greater than 400 cm/s in the main renal artery
- RAR greater than 3.5 with aliasing artifact
- Reversed diastolic flow in the interlobar arteries
Correct answer: Absence of Doppler signal in the main renal artery with a tardus-parvus waveform in the parenchyma
Occlusion produces no detectable Doppler signal in the main renal artery, while residual parenchymal flow shows a tardus-parvus pattern from collateral supply.
Question 7: What does a resistive index (RI) greater than 0.80 in the renal parenchymal vessels suggest when evaluating for renovascular hypertension?
- Intrinsic renal parenchymal disease that may limit benefit from revascularization (Correct answer)
- High-grade renal artery stenosis requiring urgent intervention
- Normal renal vascular resistance in an elderly patient
- Acute renal vein thrombosis
Correct answer: Intrinsic renal parenchymal disease that may limit benefit from revascularization
An RI >0.80 suggests elevated intrinsic renal vascular resistance, indicating parenchymal disease that often predicts poor response to renal artery stenting.
RVT Abdominal Vascular Duplex Exams 2
Which Doppler waveform characteristic is most consistent with significant celiac artery stenosis?