Sound and media

Question 1

What does attenuation mean?

Answer 1

to weaken

Question 2

What does amplification mean?

Answer 2

to strengthen

Question 3

What does 3db mean

Answer 3

double

Question 4

What does 10 db mean?

Answer 4

ten times greater

Question 5

What does -3db mean?

Answer 5

half

Question 6

What does -10db mean

Answer 6

one-tenth

Question 7

As a sound wave propagates through a medium does it increase or decrease in intensity?

Answer 7

decrease in intensity

Question 8

What term is used to describe the decrease in intensity, power, and amplitude as sound travels through a medium?

Answer 8

propagation

Question 9

What is attenuation determined by

Answer 9

Path length and frequency of sound.

Question 10

True or false, distance indirectly affects attenuation?

Answer 10

false, distance directly affects attenuation

Question 11

As sound travels, does the attenuation become greater or smaller?

Answer 11

greater

Question 12

As sound travels, does the beam become weaker or stronger?

Answer 12

weaker

Question 13

How are distance and attenuation related?

Answer 13

directly

Question 14

What does attenuation in soft tissue depend on?

Answer 14

frequency

Question 15

How are frequency and attenuation related?

Answer 15

Greater

Question 16

Is attenuation greater or lower in higher frequency?

Answer 16

Lower

Question 17

Is attenuation greater or lower in lower frequency?

Answer 17

lower

Question 18

How is attenuation measured?

Answer 18

Decibels

Question 19

How is attenuation reported?

Answer 19

As a relative change

Question 20

When imaging at a shallow depth is attenuation low or high?

Answer 20

Low

Question 21

When imaging at a deep depth is attenuation low or high?

Answer 21

High

Question 22

true or false, -10db has the same meaning as attenuating 10 db?

Answer 22

True

Question 23

What processes contribute to attenuation?

Answer 23

1. Reflection
2. Absorption
3. scattering

Question 24

What weakens the portion of the sound wave that continues to move in the forward direction?

Answer 24

reflection

Question 25

What occurs when dimensions of a boundary are large?

Answer 25

reflection

Question 26

Whare are 2 forms of reflection?

Answer 26

1. specular 2. diffuse

Question 27

True or false, specular reflection at an angle returns directly to the transducer?

Answer 27

False, They do Not return to the transducer

Question 28

Is specular reflection organized or disorganizded?

Answer 28

Organized

Question 29

When the boundary of an object is smooth, how is the sound reflected?

Answer 29

In one direction

Question 30

What term is used when a wave reflects off an irregular surface and radiates in multiple directions?

Answer 30

Diffuse reflection or backscatter

Question 31

What term is used for the random disorganized, chaotic redirection of sound?

Answer 31

scattering

Question 32

When does sound wave scatter?

Answer 32

When tissue interface is small ( equal to or less the wavelength)

Question 33

Do higher or lower frequency sound waves scatter more?

Answer 33

Higher

Question 34

How is scattering related to frequency?

Answer 34

Directly related

Question 35

What type of scattering occurs when a dimension of an object is much smaller than the beams wavelength?

Answer 35

Rayleigh related

Question 36

True or false, rayleigh scattering redirects sound waves equally in all directions.

Answer 36

True

Question 37

What type of scattering is seen with the interaction of ultrasound and red blood cells?

Answer 37

Rayleigh scattering

Question 38

What is Rayleigh scattering proportional to?

Answer 38

Frequency

Question 39

When you increase frequency, what happens to Rayleigh scattering?

Answer 39

increases

Question 40

What occurs when ultrasonic energy is converted into another form of energy?

Answer 40

Absorption

Question 41

how is absorption related to frequency?

Answer 41

Directly related

Question 42

Do lower or higher frequency waves attenuate more?

Answer 42

higher frequency (due to absorption)

Question 43

What does total attenuation depend on?

Answer 43

Frequency of sound tissue distance beam travels

Question 44

What is the term used for reporting attenuation?

Answer 44

attenuation coefficient

Question 45

What are the units of attenuation coefficient?

Answer 45

db/cm

Question 46

True or False, attenuation, coefficient is the number of decibels of attenuation that occur when sound travels 10 centimeters?

Answer 46

False. The attention coefficient is the number of decibels of attenuation that occur when sound travels centimeter.

Question 47

Does the value of the attenuation coefficient change when the path length changes?

Answer 47

No

Question 48

What is the equation for total attenuation?

Answer 48

Attenuation coefficient x distance

Question 49

Is sound travels at a depth of 8 cm, and the attenuation coefficient remains 2 db/cm, what is the total attenuation of the beam?

Answer 49

16 db (8 cm x 2 db/cm)

Question 49

In soft tissue, how are attenuation coefficient and frequency related?

Answer 49

Directly related

Question 49

true or false, attenuation coefficient is one-third of the frequency?

Answer 49

False. Attenuation coefficient is one-half of the frequency

Question 50

What is the equation of attenuation in soft tissue?

Answer 50

Frequency/2