Lesson 2 (Part 1)

Question 1

What kind of instruments are diagnostic US systems?

Answer 1

Pulse echo

Question 2

What do diagnostic US systems determine? (2)

Answer 2

1. Echo strength

2. Location

Question 3

How is echo strength and location determined? (2)

Answer 3

1. Directions

2. Arrival time

Question 4

What are the 4 main sections of an US instrument?

Answer 4

1. Beam former
2. Signal processor
3. Image processor
4. Display

Question 5

When do we only work with the voltage?

Answer 5

When we are beyond the transducer

Question 6

What are the instruments of a beam former? (8)

Answer 6

1. Master synchronizer
2. Pulser
3. Pulse delays
4. Transmit/receive switch
   - T/R switch
5. Amplifiers
6. Analog-to digital converters
7. Echo delays
8. Summer

Question 7

What are the components of the transmitter? (4)

Answer 7

1. Master synchronizer
2. Pulser
3. Pulse delays
4. Transmit/receive switch
   - T/R switch

Question 8

What are the components of the receiver? (4)

Answer 8

1. Amplifiers
2. Analog-to digital converters
3. Echo delays
4. Summer

Question 9

What kind of voltage do you get when you send echos?

Answer 9

Pulse voltage

- transmission

Question 10

What kind of voltage do you get when you receive echos?

Answer 10

Echo voltage

- reception

Question 11

What does the master synchronizer do?

Answer 11

It coordinates the entire system

- tells the pulser when to fire

Question 12

What does the T/R switch do?

Answer 12

Switches function

Question 13

How do you prevent range ambiguity artifact?

Answer 13

You wait for the echo to come back before you fire off the next pulse

Question 14

Range ambiguity artifact

Answer 14

Incorrect placement of an echo along the scan line

- echo misplacement

Question 15

What does the pulser do?

Answer 15

It produces an electric voltage that drives the transducer

- forms the beam that sweeps through the tissue

Question 16

Pulse

Answer 16

A single cycle of voltage of desired frequency

Question 17

What does the frequency of the voltage pulse determine?

Answer 17

The frequency of the resulting US pulse

- f(voltage) = f(pulse) = f (operating)

Question 18

What units are you using when involved voltages?

Answer 18

MHz

Question 19

What is the range of frequency for a pulser?

Answer 19

2-20 MHz

Question 20

PRF

Answer 20

Pulse repetition frequency

Question 21

Pulse repetition frequency

Answer 21

Is the number of voltage pulses sent out to the transducer each second

Question 22

What does PRF range for 2D?

Answer 22

4-15kHz

- does this automatically

Question 23

What does PRF range for doppler?

Answer 23

5-30kHz

- operator-controlled

Question 24

What does PRF(voltage) equal?

Answer 24

PRF(pulse)

- 1 pulse is produced per 1 voltage

Question 25

PRP

Answer 25

Pulse repetition period

Question 26

Pulse repetition period

Answer 26

The time it takes from the beginning of one pulse to the beginning of the next

Question 27

What does PRP(voltage) equal?

Answer 27

PRP(pulse)

Question 28

What do you need in order to receive information fast?

Answer 28

A high PRF

Question 29

What is PRF limited by?

Answer 29

Depth

Question 30

What is needed for deeper images?

Answer 30

Lower PRF

• takes more time
• decrease frame rate

Question 31

Frame rate

Answer 31

The number of images that are generated per second