Flashcards in Lesson 23 (Part 1) Deck (33)

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1

## What does spectral doppler detect? (4)

###
1. Presence

2. Speed

3. Character

4. Direction of flow

5. Quantification of blood flow

- this is super important

2

## When is the peak velocity?

### During systolic

3

## When is the end velocity?

### During diastolic

4

## What is spectral doppler also known as? (2)

###
1. Pulsed doppler

2. Pulsed wave doppler

5

## What does spectral doppler fire along?

### A single scan line

6

## How many pulses per cycle are there for spectral doppler?

### 5-30

7

## Sample volume

###
Is a specific area that is being assessed

- the gate

8

## Range gating

### Being able to select information from a specific depth

9

## What are you looking at in a smaller gate?

### A higher velocity

10

## What are 3 benefits for a smaller gate?

###
1. Less noise

2. Better quality

3. More specific information

11

## What is the formula for effective sample length?

### 1/2 SPL + gate length

12

## What is another term for sample width?

### Beam width

13

## What is sample volume dependant on?

###
The user

- user defined

14

## What is a larger gate used for?

### To look for a vessel/signal

15

## What is on the X axis for a graph of spectral doppler?

### Time

16

## What is on the y axis for a graph of spectral doppler?

### Doppler shift/velocity

17

## How does all blood move?

### As a unit

18

## When is a range of velocities obtained?

### At any particular moment in time

19

## Where does spectral doppler occur?

### Within the signal processor

20

## What is the known as the gate amplifier?

### Beam former

21

## What does quadrature phase detector allow?

###
Detection of bidirectional Doppler

- shows +/- shifts

22

## What does a filter do?

### Gets rid of the sum

23

## What does the spectrum analyzer determine? (2)

###
1. Each Doppler shift frequency

2. Its strength

24

## Where does fast fourier transform occur?

### Within the spectrum analyzer

25

## Fast fourier transform

### Mathematical technique to figure out the frequency spectrum

26

## Where are the results form the fast fourier transform sent to?

### Results sent to be displayed on the spectral display

27

## FFT

### Fast fourier transform

28

## What does spectral display show?

### Spectral waveforms

29

## What does each point on the spectral display demonstrate? (3)

###
1. Direction (+/-)

2. Magnitude

- speed

3. Amplitude

- brightness

30