Chapter 18
The 3 basic forms of blood flow
What is pulsatile, phasic, and steady?
This principle explains the change in frequency when sound reflects off moving red blood cells
What is Doppler Effect?
The term that describes the appearance of color gain that was set too high
What is color confetti?
The definition of stenosis
What is the narrowing in the lumen of a vessel?
What is moves down for inspiration and up for expiration?
The 3 types of energy loss
What is viscous, frictional, and inertial energy loss?
This artifact occurs in pulsed Doppler when the frequency shift exceeds the Nyquist limit
What is aliasing?
What happens to the color flow in a vessel when the direction of flow and sound are perpendicular
What is no color?
____ a bruit _____ a thrill
What is hear a bruit feel a thrill?
With inspiration and expiration, thoracic pressure...
What is decreases with inspiration and increases with expiration?
The number that predicts whether flow is laminar or turbulent and its value.
What is the Reynolds number; 2,000?
This equation includes velocity of blood, transducer frequency, cosine of the angle, and propagation speed
What is the Doppler equation?
This is used to fix ghosting artifact
What is the wall filter?
The law of conservation of energy
What is energy cannot be created or destroyed, only transformed?
With inspiration and expiration, the abdominal pressure...
What is increases with inspiration and decreases with expiration?
The relationship Bernoulli's Principle describes
What is the relationship between velocity and pressure moving in a fluid?
This color map mode shows turbulence by adding extra colors, often green
What is variance mode?
What a wall filter effectively eliminates
What is low frequency doppler shift?
The relationship (equation) between flow, resistance, and pressure gradient
With inspiration and expiration, venous return to the heart...
The hydrostatic pressure in an individual at the top of the head
This doppler mode can measure very high velocities but cannot determine exact depth.
What is continuous wave Doppler?
The most effective way to eliminate aliasing in color doppler imaging.
What is increasing the velocity scale?
3 Effects of a stenosis
what is
- Change in flow direction?
- increased velocity as a vessel narrows?
- turbulence downstream from the stenosis?
- Pressure gradient across the stenosis?
- loss of pulsatility?
With inspiration and expiration, venous flow in the legs...
What is decreases with inspiration and increases with expiration?