CVT Vascular Technology & Hemodynamics 2 — Questions and Answers
Question 1: Which Doppler waveform characteristic is most indicative of significant proximal arterial stenosis?
- Triphasic waveform with sharp systolic upstroke
- Monophasic waveform with slow systolic rise and reduced amplitude (Correct answer)
- Biphasic waveform with preserved diastolic flow
- High-resistance waveform with reversed diastolic component
Correct answer: Monophasic waveform with slow systolic rise and reduced amplitude
Significant proximal stenosis produces a tardus-parvus waveform that is monophasic with a slow systolic rise (tardus) and reduced peak velocity (parvus).
Question 2: During a venous duplex exam, a non-compressible femoral vein with absence of phasicity most likely indicates:
- Normal venous anatomy
- Acute deep vein thrombosis (Correct answer)
- Chronic venous insufficiency
- External compression from lymphadenopathy
Correct answer: Acute deep vein thrombosis
Acute DVT causes the vein to become non-compressible and loses the normal phasic respiratory variation due to intraluminal thrombus.
Question 3: The ankle-brachial index (ABI) value of 1.3 in a diabetic patient most likely suggests:
- Normal arterial perfusion
- Mild peripheral arterial disease
- Severe ischemia requiring intervention
- Non-compressible calcified vessels giving falsely elevated reading (Correct answer)
Correct answer: Non-compressible calcified vessels giving falsely elevated reading
An ABI greater than 1.3 indicates vessel wall calcification causing incompressibility, which is common in diabetic and renal failure patients, rendering the ABI unreliable.
Question 4: Which parameter best quantifies the severity of renal artery stenosis on duplex ultrasound?
- Renal artery peak systolic velocity alone
- Renal-to-aortic ratio (RAR) greater than 3.5 (Correct answer)
- Resistive index of the renal parenchyma
- End-diastolic velocity of the renal artery
Correct answer: Renal-to-aortic ratio (RAR) greater than 3.5
A renal-to-aortic ratio (RAR) greater than 3.5 combined with peak systolic velocity >180 cm/s is the standard duplex criterion for significant renal artery stenosis.
Question 5: During carotid duplex imaging, an ICA/CCA peak systolic velocity ratio greater than 4.0 correlates with what degree of stenosis?
- 50–59%
- 60–69%
- 70–79%
- 80–99% (Correct answer)
Correct answer: 80–99%
An ICA/CCA PSV ratio >4.0 corresponds to 80–99% stenosis according to the Society of Radiologists in Ultrasound consensus criteria.
Question 6: The hepatic artery resistive index (RI) is elevated above 0.8 in a liver transplant patient. This finding is most consistent with:
- Normal post-transplant hepatic flow
- Hepatic artery thrombosis
- Hepatic artery stenosis with elevated downstream resistance (Correct answer)
- Portal vein thrombosis
Correct answer: Hepatic artery stenosis with elevated downstream resistance
An elevated RI in the hepatic artery post-transplant suggests increased downstream vascular resistance, often due to hepatic artery stenosis or rejection.
Question 7: Which maneuver is used to evaluate for subclavian steal syndrome during a vascular ultrasound examination?
- Valsalva maneuver
- Reactive hyperemia cuff release
- Arm exercise or blood pressure cuff inflation on the ipsilateral arm (Correct answer)
- Head turning to the contralateral side
Correct answer: Arm exercise or blood pressure cuff inflation on the ipsilateral arm
Arm exercise or cuff inflation/release on the affected side increases demand and provokes reversal of vertebral artery flow, confirming subclavian steal.
CVT Vascular Technology & Hemodynamics 2
Which Doppler waveform characteristic is most indicative of significant proximal arterial stenosis?