lecture 23

Question 1

Spectral doppler

Answer 1

Presence, speed, chharacter and direction of blood flow

Quanitification of blood flow

Question 2

Peak systolic velocity vs end diastolic

Answer 2

Peak systolic is top of highest peak

And diastolic is the smaller peak after the large one

Question 3

Spectral doppler aka

Answer 3

Pulsed doppler

Pulsed wave doppler

Question 4

Spectral doppler fires along ____________ at ______ cycles per pulse

Answer 4

Single scan line

5-30 cycles per pulse

Question 5

Sample volume

Answer 5

Specific area that is being assessed

Aka gate

Question 6

Range gating

Answer 6

Being able to select information from a speciifc depth

Question 7

Sample volume made of (2)

Answer 7

Effective sample length and sample width

Question 8

Effective sample length =

Answer 8

0.5(SPL) + gate length

Question 9

Sample width =

Answer 9

Beam width

Question 10

Sample volume is _____defined

Answer 10

User

Question 11

Larger gate lengths for

Answer 11

Looking for a vessel/ signal

Question 12

Smaller gate lengths for

Answer 12

More specific info, less noise, better quality of spectral waveform

Question 13

Samples taken in x and y axis in colour doppler

Answer 13

X axis = time
Y axis = doppler shift/velocity

Then smoothed

Question 14

Realistically ______________ is obtained at any particular moment in time

Answer 14

A range of velocities

Question 15

Blood cells _______ are picked up

Answer 15

Moving at different speeds

Question 16

We are usually concerned with the _____ speeds of the spectra

Answer 16

Fastest

Question 17

Spectral doppler is all happening within the _____

Answer 17

Signal processor

Question 18

Quadrature phase detector allows

Answer 18

Detection of bidirectional doppler, meaning we can see positive negative shifts

Question 19

Mixer in the signal processor

Answer 19

Mixees fR+ fT and fR-fT

Question 20

Filter in the signal processor get rid of

Answer 20

The sum of fR+fT

Question 21

Spectrum analyzer determines

Answer 21

Each doppler shift freq and its strength

Question 22

Fast fourier transform occurs within

Answer 22

The spectrum analyzer

Question 23

Fast fourier transform is what

Answer 23

A mathmatical technique to figure out the frequency spectrum

Question 24

Fast fourier transform results sent to

Answer 24

Be displayed on the spectral display

Question 25

Spectral display shows

Answer 25

Spectral waveforms

Question 26

The x and y axis on spectral display are

Answer 26

X- time | Y- doppler shift/velocity

Question 27

On spectral display each point shows (3)

Answer 27

Direction (+/-) Magnitude (how fast) Amplitude (brightness)

Question 28

What factors affect direction on the spectral display

Answer 28

Whether it is coming towards or away from the transducer Affected by direction of probe/steering

Question 29

What factors affect magnitude on spectral displau

Answer 29

Speed of blood flow | Doppler angle

Question 30

Larger doppler angle = _______ doppler shift and ______ velocity calculated

Answer 30

Smaller and slower

Question 31

What factors can affect amplitude on spectral display

Answer 31

Brightness/ intensity of returning echo Concentration of RBCs/ reflectors/impedances

Question 32

Spectral controls (4)

Answer 32

Gate size/ sample volume Gain Spectral invert Baseline

Question 33

Spectral contols are similar to

Answer 33

colour controls