Question

What remains when the reflected intensity is subtracted from the Incident intencity?

reflected intensity coefficient

transmitted intensity Coefficient

transmitted intensity

100

Question 2

2 Points

The phenomenon that occurs when the beam strikes a small reflector with a diameter of less than the sound wavelength is referred to as:

none of the choices are correct

specular reflections

Snell's scattering

Rayleigh's scattering

Question 3

2 Points

_________________________ is when sound crosses a boundary, has oblique incidence and the speed changes:

attenuation

grating lobes

reflection

refraction

Question 4

2 Points

How long does it take for sound to make a round trip to and from the skin's surface to a reflector depth of 1 cm in soft tissue?

A. 13 ps B. 150 ms

c. 15 vs

D. 2 seconds

6.5 ms

13 ms

13 μs

6.5 μs

Question 5

2 Points

Amplitude and intensity are indicators of the strength of the sound wave.

True

False

Question 6

2 Points

The rate that sound travels through a medium is known as which of the following? .

Echogenicity

Propagation speed.

Attenuation speed.

velocity

Question 7

2 Points

When sound travels, as the distance increases, the attenuation of ultrasound in soft tissue will:

decrease

increase

double

None of the choices are correct

Question 8

2 Points

what is the speed of sound thrugh bone

greater than the speed of sound in air and soft tissue

less than the speed of sound in fluis

equal to the speed of sound in soft tissue

less tha the speed of sound in air

Question 9

2 Points

What is the total attenuation in soft tissue for a 4 MHz frequency at 2 cms.?

4 dB/cm

4 dB

4 Z

40 dB

Question 10

2 Points

What statement is most correct regarding ultrasound absorption?

Reflection is not a contributor

Absorption is the major part of attenuation

Frequency does not impact the amount of absorption that occurs

Absorption is greater in fluids than soft-tissue

Question 11

2 Points

An ultrasound wave is traveling through soft tissue. Its intensity undergoes six decibels of attenuation. How does the final intensity of the wave relate to the intensity of the wave when it started its journey?

it is now one-tenth as large

it is now six times larger

it is now one-fourth as large

it is now four times larger

Question 12

2 Points

What is true of scattering?

It goes in one direction

It goes in all directions

It bounces back and forth from the boundary to the transducer

it goes in a single direction away from the transducer

Question 13

2 Points

As frequency increases, attenuation:

decreases

neither

increases

Answer 1

q1) total intensiry= reflected +transmitted

so after subtracting refelected transmitted intensity remains

q2) rayleigh scattering occurs

q3) reflection is when sound crosses a boundary, has oblique incidence and the speed changes:

q4) speed of sound is 1500m/s in human tissue

and for round trip distance = 2cm =0,02 m

so, time in round trip of 1cm is t= 0.02/1500=13 micro s

q5) True

q6) propagation speed

q7) increase

q8) greater than the speed of sound in air and soft tissue

q9) so as

for muscle or tissue alpha =1.09

so we get

attenuation =4 dB/cm

q10)Absorption is the major part of attenuation

q11)it is now six times larger

q12)It goes in all directions

q`13)increases