Mixed Deck — All VT Topics Flashcards

What surveillance interval does KDOQI recommend for monitoring AVG access flow in clinically stable patients?

Answer: Every 3 months

KDOQI guidelines recommend access flow measurement every 3 months for AVGs given their higher thrombosis rate compared to AVFs.

In the context of dialysis access surveillance, what role does continuous professional development play for VT practitioners?

Answer: It ensures practitioners remain current with evolving standards, technologies, and best practices

Continuous professional development is essential in dialysis access surveillance because it ensures VT practitioners remain current with evolving standards, technologies, and best practices, maintaining competency throughout their careers.

Which finding on duplex ultrasound is most suggestive of venous outflow stenosis in a dialysis AV fistula?

Answer: Pulsatile waveform throughout the fistula

Outflow stenosis causes increased resistance, converting the normally low-resistance venous waveform to a pulsatile pattern throughout the fistula.

Which test is used to evaluate venous reflux and valve function?

Answer: Venous duplex ultrasound

Venous duplex ultrasound is the primary test used to evaluate venous reflux and valve function, particularly in cases of chronic venous insufficiency. This technique uses both B-mode imaging to visualize the veins and Doppler to assess blood flow direction and velocity. It can detect incompetent valves by observing retrograde blood flow, which indicates reflux.

Aliasing on color Doppler is recognized by:

Answer: An abrupt transition from one color to the opposite color (color reversal)

Aliasing appears as an abrupt wrap-around from the maximum positive color to the maximum negative color (or vice versa) when velocities exceed the Nyquist limit.

Endovenous heat-induced thrombus (EHIT) is a recognized complication of which vascular procedure?

Answer: Endovenous thermal ablation (laser or radiofrequency)

EHIT occurs when thermally induced thrombus propagates from the treated superficial vein into the deep venous system at the saphenofemoral or saphenopopliteal junction.

Which duplex ultrasound finding is characteristic of vertebral artery steal syndrome (subclavian steal)?

Answer: Complete reversal of flow direction in the ipsilateral vertebral artery

Subclavian steal causes complete flow reversal in the ipsilateral vertebral artery as it supplies the arm via retrograde flow.

Which finding on transcranial Doppler (TCD) is MOST consistent with vasospasm following subarachnoid hemorrhage?

Answer: MCA mean flow velocity > 120 cm/s with Lindegaard ratio > 3

MCA velocity >120 cm/s and Lindegaard ratio (MCA/ICA) >3 distinguish vasospasm from hyperemia.

What is the PRIMARY reason continuous wave (CW) Doppler is used instead of duplex in ABI measurement?

Answer: CW Doppler is not depth-selective and detects the highest-velocity signal from any depth

CW Doppler has no range gate, sampling all signals along the beam path, making it reliable for detecting audible flow from poorly localized vessels.

In the context of abi & segmental pressure testing, what role does continuous professional development play for VT practitioners?

Answer: It ensures practitioners remain current with evolving standards, technologies, and best practices

Continuous professional development is essential in abi & segmental pressure testing because it ensures VT practitioners remain current with evolving standards, technologies, and best practices, maintaining competency throughout their careers.

During normal respiration, the augmentation of venous return to the right heart is caused by:

Answer: Decreased intrathoracic pressure on inspiration

Inspiration lowers intrathoracic pressure, expanding the right atrium and great veins, which decreases central venous pressure and augments venous return.

Which of the following is a fundamental principle of transcranial doppler imaging as it applies to Vascular Technician Certification?

Answer: Systematic evaluation and adherence to established industry standards

A fundamental principle of transcranial doppler imaging in Vascular Technician Certification is the systematic evaluation and adherence to established industry standards, which ensures consistency, quality, and regulatory compliance across all professional activities.

A VT professional encounters an unfamiliar situation while performing transcranial doppler imaging duties. What is the most appropriate first action?

Answer: Consult relevant standards, guidelines, or a qualified supervisor before proceeding

When facing unfamiliar situations in transcranial doppler imaging, the most appropriate action is to consult relevant standards, guidelines, or a qualified supervisor. This ensures safety, accuracy, and compliance while building professional knowledge.

In the context of ultrasound physics & doppler principles, what role does continuous professional development play for VT practitioners?

Answer: It ensures practitioners remain current with evolving standards, technologies, and best practices

Continuous professional development is essential in ultrasound physics & doppler principles because it ensures VT practitioners remain current with evolving standards, technologies, and best practices, maintaining competency throughout their careers.

During a graft surveillance duplex exam, which finding MOST urgently requires intervention to prevent graft thrombosis?

Answer: Graft PSV 3.5

Low graft flow velocity (3.5) predicts impending thrombosis and warrants urgent revision.

Which parameter is used to calculate the Resistive Index (RI) in renal duplex ultrasound?

Answer: (PSV − EDV) / PSV

RI = (PSV − EDV) / PSV; values >0.70 suggest increased downstream resistance or intrinsic renal disease.

When documenting activities related to abi & segmental pressure testing, which practice is considered essential for VT certification holders?

Answer: Maintaining comprehensive records that include procedures, observations, results, and any anomalies

Comprehensive documentation that includes procedures, observations, results, and any anomalies is essential in abi & segmental pressure testing. This supports quality assurance, enables peer review, and satisfies regulatory and audit requirements.

A non-compressible vessel with an ABI of 1.4 is MOST likely due to:

Answer: Medial arterial calcification (Mönckeberg sclerosis)

Medial calcification makes vessels incompressible, falsely elevating ABI >1.30; toe-brachial index (TBI) should be used instead.

Which spectral Doppler finding indicates a hemodynamically significant stenosis within the sample volume?

Answer: Spectral broadening with filling of the spectral window and elevated PSV

Turbulent flow at a stenosis fills the spectral window (spectral broadening) and is associated with markedly elevated PSV.

What is the primary ethical obligation of a VT professional when a conflict of interest arises during carotid & vertebral ultrasound activities?

Answer: Disclose the conflict to all relevant parties and recuse from the decision if necessary

The primary ethical obligation when a conflict of interest arises in carotid & vertebral ultrasound is to disclose it to all relevant parties and, if necessary, recuse from the decision. This maintains professional integrity and stakeholder trust.