Vascular Technology & Hemodynamics Flashcards
7 cards from real CVT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Vascular Technology & Hemodynamics flashcards as text
Which color flow Doppler finding is characteristic of arteriovenous fistula (AVF) formation after femoral artery catheterization?
Answer: High-velocity, low-resistance arterialized flow in an adjacent vein
An AVF produces arterialized (pulsatile, high-velocity) flow in the draining vein due to direct communication between the artery and vein, with high diastolic flow in the feeding artery.
The resistive index (RI) is calculated as:
Answer: (PSV - EDV) / PSV
Resistive index = (PSV − EDV) / PSV, where PSV is peak systolic velocity and EDV is end-diastolic velocity; it reflects downstream vascular resistance.
During intraoperative duplex scanning of a carotid endarterectomy site, a focal area of reversed color flow at the distal end point of the endarterectomy is most consistent with:
Answer: Intimal flap or step defect causing flow separation
A focal reversed color zone at the distal endarterectomy end point suggests an intimal flap or step defect that creates flow separation and potential thrombosis risk.
Which finding on portal vein duplex indicates portal hypertension?
Answer: Portal vein diameter greater than 13 mm with hepatofugal (reversed) flow
Portal vein dilation greater than 13 mm with hepatofugal (away from liver) flow direction is a hallmark of severe portal hypertension with reversal of normal hepatopetal flow.
A patient has an ABI of 0.55 at rest. After treadmill exercise the ABI drops to 0.30 and recovers slowly. This pattern indicates:
Answer: Hemodynamically significant arterial occlusive disease with exercise-induced ischemia
A post-exercise drop in ABI that recovers slowly confirms hemodynamically significant PAD where collateral supply is insufficient to meet the increased metabolic demand of exercise.
Which duplex velocity criterion is used to diagnose significant (≥60%) renal artery stenosis?
Answer: RAR > 3.5 and PSV > 180–200 cm/s
The widely accepted criterion for ≥60% renal artery stenosis is PSV >180–200 cm/s combined with a renal-to-aortic ratio (RAR) >3.5.
Which of the following best describes the Bernoulli principle as applied to arterial stenosis?
Answer: Pressure drops as velocity increases through a stenosis
Bernoulli's principle states that as fluid velocity increases through a stenosis, pressure decreases, which is why high-grade stenoses cause significant pressure gradients across the lesion.