ARDMS SPI Hemodynamics and Vascular Flow Principles

Question 1

Laminar flow in a vessel is characterized by:

Accepted Answer

Concentric layers of blood moving at different velocities with fastest flow centrally

Answer

In laminar flow, blood moves in concentric layers (parabolic profile) with the fastest velocity at the center and slowest near the walls due to friction.

Question 2

Turbulent flow on a spectral Doppler waveform appears as:

Accepted Answer

Spectral broadening with filling in of the spectral window

Answer

Turbulence causes blood cells to move at many different velocities simultaneously, resulting in spectral broadening and filling in of the normally clear spectral window.

Question 3

According to the Bernoulli principle, as blood flows through a stenosis, what happens to velocity and pressure?

Accepted Answer

Velocity increases, pressure decreases

Answer

Energy conservation (Bernoulli principle) dictates that at a stenosis, the cross-sectional area decreases so velocity must increase while pressure drops.

Question 4

The resistivity index (RI) is calculated as:

Accepted Answer

(PSV − EDV) / PSV

Answer

The Resistivity Index = (Peak Systolic Velocity − End Diastolic Velocity) / Peak Systolic Velocity, reflecting downstream vascular resistance.

Question 5

A high-resistance Doppler waveform pattern is typically found in which vessel?

Accepted Answer

Femoral artery at rest

Answer

The femoral artery at rest supplies skeletal muscle which has high resting vascular resistance, producing a triphasic high-resistance waveform.

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI Hemodynamics and Vascular Flow Principles