week 2- Doppler Blood flow

Question 1

Degree of pulse wave dampening

Answer 1

pulsatility

Question 2

𝑷ulsatility Index equation

Answer 2

PI=(𝑺−𝑫)/𝑴

• peak systolic
• minimum diastolic
• mean velocity

Question 3

Pulsatility index is ___ of the angle

Answer 3

independent

Question 4

flow that is dampened by ___ disease will have a LOWER PI

Answer 4

proximal

Question 5

low PI indicated

Answer 5

disease proximal to the transducer

Question 6

after exercise high pulsatility extremity arteries become ____ pulsatility

Answer 6

low

Question 7

Resistive index equation

Answer 7

𝑹𝑰 =(𝑷𝑺𝑽−𝑬𝑫𝑽)/𝑷𝑺𝑽

• peak systolic velocity
• end diastolic velocity

Question 8

Measure of pulsatile blood flow that reflects the resistance to blood flow caused by microvascular bed distal to the site of measurement.

Answer 8

resistive index

Question 9

resistance index of 0 means

Answer 9

continuous flow

Question 10

resistance index of 1

Answer 10

systolic flow, no diastolic

Question 11

resistance index of -1

Answer 11

reversed diastolic flow

Question 12

RI is an indicator of ____ resistance

Answer 12

peripheral

Question 13

Higher resistance flow if there is disease ___ to the probe

Answer 13

distal

Question 14

if resistance index is between 0 and 1 it means there is ___ flow towards the organ

Answer 14

constant

Question 15

an organ where you would find constant flow

Answer 15

brain, placenta, CCA, vertebral

Question 16

the following are indicators of ___ flow:

• Central velocities are greater than peripheral velocities in a vessel
• Uniform velocity
• Clear spectral window

Answer 16

laminar flow

Question 17

the following are indicators of ___ flow:

• Non uniform and disorganized blood flow
• Spectral broadening – filling of the spectral window proportionate to severity of flow disturbance
• Indicative of pathology but can occur normally

Answer 17

turbulent

Question 18

The following is seen with ___ resistance flow:
Broad systolic peaks
Forward flow through diastole
Monophasic

Answer 18

low

Question 19

The following is seen with ____ resistance flow:
PS is tall and sharp in diastole
Forward flow is always present throughout diastole

Answer 19

moderate

Question 20

low pulsatility is associated with ___ resistance flow

Answer 20

low

Question 21

ECA, SMA during fasting present with ___ flow

Answer 21

moderate resistance

Question 22

what waveforms will NEVER cross the baseline

Answer 22

low, moderate

Question 23

t/f: low flow is always above base line

Answer 23

FALSE - can be below depending if the scale is inverted

Question 24

the following is seen with ___ resistance flow:
Tall, narrow and sharp systolic peaks
Reversed or absent ED flow
Triphasic waveform

Answer 24

high

Question 25

high pulsatility is seen in ____ arteries and indicates ___ resistance flow

Answer 25

- extremity | - high

Question 26

3 phases in triphasic waveform

Answer 26

1. sharp systolic 2. brief reversal flow 3. brief forward flow

Question 27

What superimposes a blood flow image on a standard grey scale image

Answer 27

colour doppler

Question 28

Veins have a ___ PRF (gains), why?

Answer 28

lower | -to detect low velocities

Question 29

arteries have a ___scale, why?

Answer 29

higher | -limit aliasing

Question 30

increasing the scale ____ the aliasing

Answer 30

decreases

Question 31

doppler angle

Answer 31

45-60 degrees

Question 32

why is doppler angle important

Answer 32

tell what way blood is flowing

Question 33

colour box width decreases the ___

Answer 33

frame rate

Question 34

too much colour gain can cause ____

Answer 34

bleeding | -misrepresentation of colour flow outside vessel, making pathology

Question 35

increasing gain increases the ___ of the signal

Answer 35

amplitude

Question 36

This technique eliminates artifacts caused by heart and vascular pulsation

Answer 36

wall filter

Question 37

wall filter reduces ___ frequency noise

Answer 37

low

Question 38

what is the risk of setting the wall filter too high

Answer 38

difficulty detecting slow flow

Question 39

changes the colour velocity range

Answer 39

baseline

Question 40

changes what colour represents flow towards the transducer

Answer 40

invert

Question 41

what does a colour map show

Answer 41

the doppler signal

Question 42

increasing luminance of red and blue indicate increasing ___ and ___ doppler shifts respectively

Answer 42

- positive | - negative

Question 43

the minimum number of samples required to avoid aliasing; doppler shift freq above which aliasing occurs

Answer 43

nyquist limit

Question 44

a misrepresentation of the Doppler shift in a negative direction occurring when the pulse repetition frequency is set too low

Answer 44

alaising

Question 45

colour doppler is/ is not angle dependent?

Answer 45

IS

Question 46

advantages of doppler

Answer 46

- Demonstrates blood flow - Determines direction of flow - Demonstrates non-vascular motion (ureteral jets) - Asses flow in the entire lumen – not just within the doppler gate - Can help differentiate between occlusion and severe stenosis

Question 47

True flow reversal involves ___ regions between the opposite colours

Answer 47

dark

Question 48

what is a stenosis

Answer 48

narrowed portion of arterial lumen

Question 49

there is a ____ velocity through the stenotic zone to maintain flow volume

Answer 49

increased

Question 50

what are the 3 important velocity measurements

Answer 50

Peak systolic volume End diastolic volume PSV ratio

Question 51

what is the first parameter to increase as the lumen narrows

Answer 51

PSV

Question 52

<50% stenosis generally EDV is

Answer 52

unaffected

Question 53

moderate stenosis (50-70%) EDV ___

Answer 53

increases proportionally to degree of stenosis

Question 54

severe stenosis (>70%) EDV ____

Answer 54

can be very high

Question 55

allows for patient to patient hemodynamic variables (PT is their own physiologic standard)

Answer 55

PSV ratio

Question 56

Maximum ____ occurs within the 1st cm beyond the stenosis, minimizes by 2cm and normalizes by 3cm

Answer 56

turbulence

Question 57

spectral broadening and flow reversal is indicative of

Answer 57

turbulence

Question 58

increased RI would be shown ___ from the stenosis

Answer 58

distal (down the road)

Question 59

Pulsatile index tells you what happened ____ measurement

Answer 59

proximal (before)

Question 60

what is Tardus Parvus

Answer 60

pattern of doppler waveform resulting from arterial stenosis

Question 61

In Tardus Parvus, it takes ____ (more/less) time to reach peak velocity

Answer 61

more

Question 62

in tardus parvus, flow velocity is ____

Answer 62

low

Question 63

Decreased peripheral resistance allows blood to flow through diastole in ____

Answer 63

tardus parvus