doppler for echo

Question 1

doppler effect

Answer 1

change in frequency of an energy wave who is relative to the wave source

Question 2

doppler shift

Answer 2

difference between the transmitted signal and the received signal

Question 3

what affects the magnitude of a doppler shift?

Answer 3

the velocity of the reflector
the frequency of the initial sound
the angle

Question 4

color doppler shows

Answer 4

flow frequencies in different colors indicating blood flow velocity and direction

Question 5

when does aliasing occur

Answer 5

when velocities are higher than the max allowed by the color scale
need to increase the color scale

Question 6

spectral doppler

Answer 6

y axis is amplitude and x axis is time

cursor angle should be as close to 0 degrees as possible

Question 7

PW doppler

Answer 7

have 1 crystal

can select a location to measure velocity

Question 8

nyquist limit

Answer 8

the maximum velocity that can be measured

1/2 the PRF

Question 9

sample volume

Answer 9

depth of the velocity

measures time of flight

Question 10

pedoff probe

Answer 10

CW probe 
non imaging 
uses 2 crystals 
used to assess the severity of AS 
3 locations: apical, right parasternal, supraparasternal

Question 11

tissue doppler

Answer 11

estimation of myocardial velocities based on PW doppler and color doppler