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 duplex finding best differentiates a pseudoaneurysm from a true aneurysm of the femoral artery?
Answer: To-and-fro flow pattern in the neck connecting the lesion to the artery
A pseudoaneurysm demonstrates a characteristic to-and-fro (yin-yang) Doppler signal in its neck, reflecting systolic filling and diastolic outflow back into the artery.
Segmental limb pressures showing a drop of greater than 20 mmHg between adjacent levels is considered significant for:
Answer: Arterial occlusive disease at the level between the measurements
A pressure gradient greater than 20 mmHg between adjacent segmental levels indicates hemodynamically significant arterial occlusive disease between those measurement points.
In carotid duplex imaging, the presence of a 'string sign' refers to:
Answer: Severely narrowed residual lumen with a thin trickle of flow in near-total occlusion
A string sign describes the thread-like residual lumen seen in near-total internal carotid artery occlusion, with only a thin trickle of color Doppler flow visible.
During a lower extremity venous exam, which maneuver best evaluates for popliteal vein reflux?
Answer: Distal calf compression and release with patient standing
Distal calf augmentation followed by sudden release, performed with the patient standing or in reverse Trendelenburg, produces retrograde flow that reveals popliteal valve incompetence.
The vertebral artery Doppler waveform shows complete reversal of flow direction. This is diagnostic of:
Answer: Complete subclavian steal syndrome
Complete reversal of vertebral artery flow direction indicates complete subclavian steal, where the ipsilateral arm's demand reverses vertebral flow to bypass a proximal subclavian occlusion.
Which Doppler parameter is most useful for evaluating peripheral venous reflux duration?
Answer: Reflux duration greater than 500 milliseconds after augmentation release
Reflux lasting more than 500 ms (0.5 seconds) after augmentation release is the accepted threshold for pathologic venous valve incompetence in peripheral veins.
A patient with suspected thoracic outlet syndrome should have vascular ultrasound performed:
Answer: With the arm in provocative positions such as abduction and external rotation (ABERE)
Provocative positioning such as abduction and external rotation (ABERE or hyperabduction maneuver) stresses the thoracic outlet and can unmask subclavian compression not seen at rest.