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A_arterial duplex and indirect > Doppler Waveform Analysis > Flashcards

Doppler Waveform Analysis Flashcards

1
Q

what are the capabilities of physiologic testing

A

diagnosis aprox location & severity of arterial occlusive disease
gives functional information
does not discriminate between stenosis or complete occlusion

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2
Q

limitations of physiologic testing

5

A 
cast/bandages
ambient temp affects waveform quality 
CHF results in dampened WF
cannot be specific for stenosis or occlusion 
tech dependent and often difficult test
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3
Q

Patient position during test is important during what part

A

sentimental pressures due to hydrostatic pressures

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4
Q

other positions besides supine for physiologic testing

A

rt / lft lateral decubitus

prone

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5
Q

what is the Doppler effect

A

blood is moving target , transducer is stationary

wave is reflected from moving target, frequency of wave is received as different (that difference is doppler shift) from the transmitted frequency

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6
Q

The doppler effect occurs with ______ motion between the ____ and the _____ of sound

A

relative motion

between the source and the receiver of sound

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7
Q

with continuous wave Doppler one crystal is ______sending ultrasound while the other is _________receiving reflected waves

A

continuously

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8
Q

the reflected frequency can be higher or lower depending on the transmitted frequency depending on the direction of flow (T/F)

A

True

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9
Q

two types of velocimetry are _______ and _____

A

zero crossing frequency meter - analog system

FFT fast fourier transform - duplex system (digital)

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10
Q

what is the paper speed set on zero crossing frequency meter

A

25mm/sec

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11
Q

high freq waves have ____oscillations

A

many

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12
Q

low freq waves have _____oscilations

A

few

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13
Q

zero crossing freq meter counts how many times the _____ crosses over the ______

A

oscillations cross over the baseline

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14
Q

direction of blood flow _____with cardiac cycle

A

varies

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15
Q

machine estimates _______ present in _____ _____ and displays them

A

frequencies

reflected signals

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16
Q

what are drawbacks of zero crossing frequency meter

2

A 
noise 
less sensitivity (estimation)
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17
Q

when system is activated __________ is done

A

self calibraration

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18
Q

important to remember about zero crossing frequency meter system ??????

A

It averages out the reflected frequencies

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19
Q

what does the y and x axis represent in the interpreting the zero crossing frequency meter and the FFT spectral analysis system

A

y is distance (meters) of frequency shifts

x is time

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20
Q

Doppler effect: when wave is reflected from a moving target, the reflected freq is diff from transmit freq. The ____ of that change is ______proportional to the speed and direction of _________

A

magnitude
directly proportional
the moving target

it is proportional to the speed and direction of flow

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21
Q

magnitude refers to

A

speed at which an object is moving or its size

22
Q

Doppler shift formula and relationships

A

change in frequency =
2 x transmit freq MHz x RBC freq cm/sec x Cos angle of ultrasound beam and flow direction
/
the speed of sound 1540 m/sec

23
Q

what MHz Doppler probe is used for waveform Doppler analysis of extremities

A

8-10 MHz

24
Q

what sites are doppler waveforms recorded on upper etremity studies
5

A 
subclav a
ax a            
Brachial a     @anticubital fossa 
Radial a           @wrist 
Ulnar a             @wrist
25
Q

doppler velocity waveforms are recorded from the following arteries bilaterally
6

A 
CFA
SFA
Pop A
PTA             (medial malleolus)
DPA             (top of the foot)
Peroneal (if necessary ) (lateral malleolus)
26
Q

with CW analysis what three things are combined for interpretation

A

waveforms audible and visual qualities + segmental pressures

27
Q

CW potential sources for error

5

A 
insufficient period of rest before test
excessive pressure on probe tip
incorrect angle of incidence
incorrect probe positron 
inadequate amount of gel
28
Q

qualitative interpretation CW
triphasic WF characteristics of UE and LE arteries

5

A 
rapid upstroke
sharp peak
rapid downstroke
flow reversal
resumption of forward flow
29
Q

biphasic WF characteristics of UE and LE arteries

5

A 
rapid upstroke
sharp peak
fairly rapid down stroke
flow reversal
* no resumption of forward flow
30
Q

monophasic WF characteristics of UE and LE arteries

4

A

slow upstroke
rounded peak
slow downstroke
no reversal

31
Q

deterioration in signal quality from _____ ______ to the _____ as well as deterioration from _______ _____ should be checked out when preforming CW doppler exam

A

from one level to the next

from previous tests

32
Q

monophasic/pulsatile signal is often obtained _____ to an obstruction

A

proximal

33
Q

vasodialation of the _____ vessels often occur with ____obstruction which reduces the _______ of the WF and causes the signals to have lower resistant _____ flow quality

A

distal vessel vasodilation occurs with
proximal obstruction reducing the
pulsitility & causes lower resistant
steady flow quality

34
Q

well collateralilzed occlusions can appear similar to flow distal to ___________

A

a stenosis

35
Q

Subclavian artery signal should look

A

high resistant multiphasic

36
Q

flow patterns in hand are ________

A

variable

may have lower resistant signals that can be

37
Q

Doppler waveforms post excercize:

Normal should appear

A

pre excercize wave form qualitites are maintained

may be augmented and contain no reverse component because of dialation of distal vascualar bed

38
Q

Doppler waveform characteristics post excersize

Abnormal

A

rounded peak, no reverse component

39
Q

Absent doppler signals may suggest __________ or _____ ______ vessel

A

occlusion or pre-occlusive vessel

40
Q

pre occlusive vessle waveform nick name

A

string sign

41
Q

the string sign on CW analog format will appear as

A

absent signal

42
Q

Analog Doppler is not capeable of portraying velocities of less than

A

6cm/sec

43
Q

Trouble shooting-

what should you do to get rid of noise

A

increase filter
turn down gain
turn machine off and on

44
Q

Trouble shooting -

what do you do if the stylus is stuck

A

re-set
or
re -center

45
Q

Trouble shooting

what do you do if the stylus is not recording

A

make sure that proper test selection and probe type is selected

46
Q

what is inflow disease and what is a common type

A

inflow represents blood flowing into the lower extremities

Aorto-iliac disease

47
Q

what is outflow disease and what would be an example

A

`blood going out into the extremities

femoral popliteal disease

48
Q

what is pulsatililty index (PI)

A

peak -to-peak frequency difference systole to systolic flow reversal
(P1 - P2)/ Average cardiac frequency

higher number is gen. indicative of disease

sometimes used the the CFA

49
Q

(AT) Acceleration time measures what

A

onset of systole to max peak

50
Q

what causes a slowing in the time interval between the onset of systole & max peak ?

A

prox arterial obstruction

51
Q

what parameter @ CFA AT suggests presence of prox iliac disease

A

> 133 msec

52
Q

a greater AT or Lesser value AT is normal ?

A

Short AT time = normal

Long AT time = abnormal

A_arterial duplex and indirect (13 decks)

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