Contrast

Question 1

What are the two types of specular scattering?

Answer 1

Acoustic (tissue interactions)
Diffusive (boundary interactions)

Question 2

What is acoustic specular scattering?

Answer 2

Object <= wavelength
Frequency increases
Direction: re-radiates isotropically

Question 3

What is diffusive specular scattering?

Answer 3

Object = wavelength
Frequency is indepedent
Direction: modest

Question 4

What is non-specular scattering?

Answer 4

Only boundary interations
Object > > wavelength
Direction: beam-surface angle

Question 5

Reflection coefficient (R)

Answer 5

R = [ (Z_1 - Z_2) / (Z_1 + Z_2) ]^2

Z = density * speed of sound

Question 6

Transmission coefficient (T)

Answer 6

T = 1 - R

Question 7

What is Snell’s Law?

Answer 7

v_2 / v_1 = theta_2 / theta_1

Question 8

Equation for dB

Answer 8

I = 10 log (R)

Question 9

What is Doppler shift?

Answer 9

∆f=PRF/2=(2 * f_0 * v * cosθ)/c

Moving the source of sound changes the perceived wavelength

Question 10

Attenuation

Answer 10

I = I_0 * e^(-mu * x)