CCI Cerebrovascular Duplex Examinations 2 — Questions and Answers
Question 1: Which waveform characteristic is MOST indicative of a high-grade internal carotid artery stenosis (>70%)?
- Increased peak systolic velocity with spectral broadening (Correct answer)
- Decreased peak systolic velocity with a sharp systolic peak
- Monophasic low-resistance waveform at the common carotid artery
- Absent diastolic flow in the vertebral artery
Correct answer: Increased peak systolic velocity with spectral broadening
High-grade ICA stenosis produces markedly elevated PSV with turbulent post-stenotic spectral broadening due to disturbed flow.
Question 2: The ICA/CCA PSV ratio is used to grade ICA stenosis; a ratio greater than what value correlates with ≥70% stenosis by NASCET criteria?
- 2.0
- 3.0
- 4.0 (Correct answer)
- 1.5
Correct answer: 4.0
An ICA/CCA PSV ratio >4.0 is consistent with ≥70% ICA stenosis per the Society of Radiologists in Ultrasound consensus.
Question 3: A patient presents with a right-sided carotid bruit. Duplex shows a focal color aliasing jet in the proximal ICA with PSV of 320 cm/s and EDV of 110 cm/s. What is the most likely stenosis category?
- 50–69% stenosis
- ≥70% stenosis (Correct answer)
- <50% stenosis
- Near-occlusion
Correct answer: ≥70% stenosis
PSV ≥300 cm/s and EDV ≥100 cm/s are consistent with ≥70% ICA stenosis by SRU criteria.
Question 4: When performing vertebral artery duplex examination, which segment is most commonly visualized using duplex ultrasound?
- V1 (ostium to transverse foramen of C6)
- V2 (intraforaminal segment) (Correct answer)
- V3 (suboccipital segment)
- V4 (intracranial segment)
Correct answer: V2 (intraforaminal segment)
The V2 intraforaminal segment between C2 and C6 is the most consistently accessible window for vertebral artery duplex imaging.
Question 5: A patient with subclavian steal syndrome would demonstrate which vertebral artery flow pattern on the affected side during reactive hyperemia of the arm?
- Antegrade flow that becomes retrograde
- Completely retrograde flow that does not change
- Bidirectional (to-and-fro) flow converting to full retrograde (Correct answer)
- Normal antegrade flow unchanged by arm exercise
Correct answer: Bidirectional (to-and-fro) flow converting to full retrograde
Partial subclavian steal shows bidirectional flow at rest that converts to complete retrograde flow during arm hyperemia as demand increases.
Question 6: Which B-mode finding on carotid duplex is classified as a complex plaque and carries increased embolic risk?
- Homogeneous echogenic plaque with smooth surface
- Heterogeneous plaque with irregular or ulcerated surface (Correct answer)
- Concentric intimal thickening without focal lesion
- Hyperechoic plaque with posterior acoustic shadowing
Correct answer: Heterogeneous plaque with irregular or ulcerated surface
Heterogeneous plaques with irregular or ulcerated surfaces are associated with increased thromboembolic risk due to plaque instability.
Question 7: During carotid duplex, the sample volume should be placed at what angle to the vessel wall to obtain an accurate Doppler velocity measurement?
- 90 degrees
- 0 degrees
- 60 degrees or less (Correct answer)
- 75 degrees
Correct answer: 60 degrees or less
A Doppler angle ≤60° is required for accurate velocity measurements; angles >60° cause significant overestimation of velocities.
CCI Cerebrovascular Duplex Examinations 2
Which waveform characteristic is MOST indicative of a high-grade internal carotid artery stenosis (>70%)?