Lesson 1

Question 1

What is the formula for frequency?

Answer 1

f = 1/T

Question 2

What is the formula for period?

Answer 2

T = 1/f

Question 3

What is the formula for wavelength?

Answer 3

lambda = c/f

Question 4

What is the formula for pulse duration?

Answer 4

PD = T x n

Question 5

What is the formula for pulse repetition frequency?

Answer 5

PRF = 1/PRP

Question 6

What is the formula for pulse repetition period?

Answer 6

PRP = 1/PRF

Question 7

What is the formula for intensity?

Answer 7

I = P/A

Question 8

What is the relationship between intensity and amplitude?

Answer 8

I = Amp ^2

Question 9

Doppler effect

Answer 9

Change in frequency caused by the motion of a source, reflector or receiver

Question 10

Doppler shift

Answer 10

Quantification of the change in frequency

Question 11

What happens to the frequency as you get closer?

Answer 11

It increases

Question 12

What happens to the frequency as you get farther?

Answer 12

It decreases

Question 13

What kind of doppler shift do you get if you move closer?

Answer 13

Positive shift

Question 14

What kind of doppler shift do you get if you move farther?

Answer 14

Negative shift

Question 15

What do we do in doppler? (3)

Answer 15

1. Fire a particular frequency
2. Measure the frequency that returns
3. Figure out the Doppler shift

Question 16

What can we calculate with doppler?

Answer 16

How fast an object is moving

Question 17

What is the formula for doppler shift?

Answer 17

Fd = Fr - Ft

Question 18

What is the formula for velocity with doppler shift?

Answer 18

V(cc/s) = 77(cm/ms) x Fd (kHz)/ f (MHz)

Question 19

Doppler angle

Answer 19

The angle of incident beam to the blood flow

Question 20

What happens if you increase you doppler angle?

Answer 20

Decrease your Doppler shift

Question 21

What happens if you decrease you doppler angle?

Answer 21

Increase your Doppler shift

Question 22

What does a higher doppler angle mean?

Answer 22

Our velocity will be calculated too low

Question 23

Where must angle correct be kept at?

Answer 23

60 deg

- to the vessel

Question 24

What does doppler show? (5)

Answer 24

1. Presence
2. Direction
3. Speed
4. Character
5. Quantification

Question 25

What are the colour doppler controls? (6)

Answer 25

1. Box 2. Map 3. Invert 4. Baseline 5. Gain 6. Wall filter

Question 26

What are the spectral doppler controls? (5)

Answer 26

1. Gate size/sample volume 2. Gain 3. Spectral invert 4. Baseline 5. Wall filter

Question 27

What does PRF affect?

Answer 27

Scale

Question 28

Where can you only change PRF?

Answer 28

In doppler | - there is no pulses in grey scale

Question 29

What happens when you decrease PRF?

Answer 29

Your scale decreases

Question 30

What does decreasing your PRF allow to show?

Answer 30

Slower flow speeds

Question 31

What happens if you decrease the PRF too much?

Answer 31

It will cause aliasing | - wrap around

Question 32

What does increasing PRF allow?

Answer 32

Increase in scale

Question 33

What does increase PRF try and show?

Answer 33

Faster flow speeds

Question 34

What does increasing the PRF too much do?

Answer 34

Doesnt show slow speeds well

Question 35

What does phasing allow?

Answer 35

Steering