Lesson 23 (Part 3) Flashcards Preview

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Flashcards in Lesson 23 (Part 3) Deck (30)
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1

What will a good sonographer do?

They will analyze the spectral display in conjunction with the colour and grayscale information to assess for normal blood flow and pathology

2

What signals do arteries have? (2)

1. They are pulsatile
2. They have higher velocity waveforms

3

What signals do arteries have? (2)

1. They are phasic
2. Lower velocity waveforms

4

What do we asses when analyzing waveforms? (4)

1. Arterial vs Venous Signals
2. High vs Low resistance flow
3. Areas of stenosis
4. Pre (proximal)/post (distal) stenosis waveforms

5

What is being looked at in resistance flow? (2)

1. Systolic portions
2. Diastolic portions

6

What does high resistance show? (5)

1. ECA, extremities
2. Quick upstroke
3. Low diastole
4. Negative flow
- below the baseline
5. More echoic

7

What does low resistance show? (7)

1. ICA/CCA, blood hungry organs (liver, renals, etc.)
2. Vasodilation
3. Slow upstroke
4. Higher diastole
5. Positive flow
- above the baseline
6. Appears more faint
7. No reversal flow

8

Where is an example where you would see low resistance?

The brain

9

What is the formula for the continuity rule?

Q = V ave x A

10

What happens to area in areas of stenosis?

It decreases
- gets more narrow

11

What happens to velocity in areas of stenosis?

It increases
- higher pressure

12

Turbulence

Surpassing Reynolds number

13

Stenosis

High velocities relative to stenosis (potential for aliasing)

14

What does stenosis have a potential for?

Aliasing

15

What is spectral broadening related to?

Turbulence

16

Spectral broadening

Wider range of spectra

17

What does spectral broadening allow? (2)

1. More “variety” of shifts
2. Narrowing of windows

18

What is the most obvious reason for spectral broadening?

Stenosis
- but can also be that you are a bad sonographer

19

What errors that can be conducted in spectral broadening? (2)

1. Increase gain
- too much
2. Increase sample volume size
- catching multiple vessels at once

20

What can tortuous vessels give you?

Larger variety of signals

21

What are downstream clues?

Increased resistance
- looks like an ECA

22

What are upstream clues?

1. Tardus Parvus waveform
2. Monophasic waveform

23

What does upstream clues suggest?

Proximal stenosis

24

What does downstream clues suggest?

Possible distal stenosis

25

Tardus Parvus waveform (2)

1. Everything is filled in the graph (cant differentiate between waves)
2. Very slow, rounded waveform

26

Monophasic waveform

Individual waves are filled in

27

What does monophasic waveforms suggest?

Possible stenosis

28

What is an example of quantitative index?

Acceleration time

29

What does acceleration tie suggest?

Resistance

30

What can acceleration time show?

Tardus Parvus
- AT > 0.07s