Module 1 - Particle Motion & Wave Propagation

Question 1

Acoustic

Answer 1

general reference to sound

Question 2

Term referencing sound, in general

Answer 2

acoustic

Question 3

Propagation

Answer 3

reference to wave travel

Question 4

Term referencing wave travel/transmission

Answer 4

propagation

Question 5

Acoustic propagation

Answer 5

reference to the effects caused by tissue on how sound travels

Question 6

Term referencing the effects caused by tissue on how sound travels

Answer 6

acoustic propagation

Question 7

Bioeffects

Answer 7

reference to the effects of ultrasound on tissue

Question 8

Term referencing the effects of ultrasound on tissue

Answer 8

Bioeffects

Question 9

What is the reverse relationship of Acoustic Propagation?

Answer 9

Bioeffects

Question 10

What is the reverse relationship of Bioeffects?

Answer 10

Acoustic propagation

Question 11

Describe sound

Answer 11

a propagating variation (form of wave) of energy which requires a medium to travel

Question 12

What does sound require in order to travel?

Answer 12

a medium

Question 13

What are acoustic Variables?

Answer 13

1. Pressure,
2. Density,
3. Particle Motion,
4. Temperature,

Question 14

What are acoustic Parameters?

Answer 14

1. Period,
2. Wavelength,
3. Frequency,
4. Propagation speed,
5. Amplitude,
6. Intensity

Question 15

What type of wave is sound?

Answer 15

longitudinal wave

Question 16

How do particles move in a longitudinal wave?

Answer 16

parallel to direction of travel (i.e. back and forth)

Question 17

In which type of wave do particles move back and forth?

Answer 17

longitudinal

Question 18

How do particles move in a Transverse wave?

Answer 18

perpendicular to direction of travel (i.e. up and down)

Question 19

How do particles move in a Shear wave?

Answer 19

all particles within the whole body of a medium oscillate, transversely

Question 20

How do particles move in a Rayleigh wave?

Answer 20

only surface particles oscillate, either transversely or longitudinally

Question 21

In which type of wave do particles move up and down?

Answer 21

Transverse

Question 22

In which type of wave do particles move parallel to the direction of travel?

Answer 22

Longitudinal

Question 23

In which type of wave do particles move perpendicular to the direction of travel?

Answer 23

Transverse

Question 24

In which type of wave do particles oscillate transversely, within the whole body of the medium?

Answer 24

Shear

Question 25

In which type of wave do only surface particles oscillate, either transversely or longitudinally?

Answer 25

Rayleigh

Question 26

Which type of wave is related to the “scatter” off ultrasound off a structure (e.g. red blood cell)?

Answer 26

Rayleigh

Question 27

What type of wave requires a medium to travel?

Answer 27

mechanical

Question 28

What type of wave can travel within a vacuum?

Answer 28

electromagnetic

Question 29

Which state of matter can support a transverse wave?

Answer 29

Solids

Question 30

What is the type of wave that can only be supported by solids?

Answer 30

Transverse

Question 31

What happens during Mode Conversion?

Answer 31

one wave is converted to another form

Question 32

Why is mode conversion significant to scanning?

Answer 32

At a tissue-bone interfaces the waves are converted from longitudinal to transverse, thus travels along the length of the bone and never returns to the transducer (therefore appears anechoic)