RVT Hemodynamics and Doppler Principles 2

Question 1

Which hemodynamic principle states that flow rate equals the pressure gradient divided by resistance?

Accepted Answer

Ohm's law analogy for blood flow

Answer

The hydraulic analogy to Ohm's law describes blood flow (Q) as the pressure difference (ΔP) divided by vascular resistance (R).

Question 2

In a stenotic vessel, where is the highest flow velocity observed according to the continuity equation?

Accepted Answer

At the site of maximum narrowing

Answer

The continuity equation (A1V1 = A2V2) requires velocity to increase at the point of greatest cross-sectional area reduction.

Question 3

What does the resistivity index (RI) formula [(PSV - EDV) / PSV] primarily reflect?

Accepted Answer

Downstream vascular resistance

Answer

The resistivity index quantifies the pulsatility of flow and correlates with peripheral vascular resistance distal to the sample site.

Question 4

A Doppler angle of 0° between the ultrasound beam and blood flow would result in:

Accepted Answer

Maximum Doppler shift

Answer

The cosine of 0° equals 1, making the Doppler equation yield maximum frequency shift when the beam is perfectly parallel to flow.

Question 5

Which waveform characteristic is most consistent with a high-resistance peripheral arterial system at rest?

Accepted Answer

Triphasic waveform with reverse flow component

Answer

Normal resting peripheral arteries (e.g., femoral) show triphasic waveforms with a brief reversal in early diastole reflecting high peripheral resistance.

(RVT) Registered Vascular Technologist Practice Test

(RVT) Registered Vascular Technologist Practice Test

RVT Hemodynamics and Doppler Principles 2