# Shared Flashcard Set

## Details

PASS BOOK
Propagation of ultrasound through tissues ch 2
20
Physics
10/25/2015

Term
 Perpendicular incidence is also known as:
Definition
 Orthogonal incidence
Term
 The term derived from the product of the density and propagation speed of a medium is known as:
Definition
 Impedence
Term
 The phenomenon that occurs when the beam strikes a small reflector with a diameter of less than the sound wavelength is referred to as:
Definition
 Rayleigh's scattering
Term
 The angle of refraction is equal to the angle of incidence:   TRUE or FALSE
Definition
 FALSE
Term
 The principle of refraction is known as:
Definition
 Snell's Law
Term
 If the propagation speed of sound is greater in the second medium, the transmission angle will:
Definition
 Increase
Term
 The factors that contribute to attenuation are:
Definition
 Scattering   Reflection   Absorption
Term
 As the stiffness of a medium increases the propagation speed:
Definition
 Increases
Term
 Which statement about higher frequencies is most correct?
Definition
 Does not affect the propagation speed
Term
 The attenuation coefficient for soft tissue is equal to ____ db/cm per MHz of frequency.
Definition
 0.5 - 1.0
Term
 Which term is used to describe the interaction of sound with irregular shaped or rough edge structures?
Definition
 Scattering
Term
 The units for impedance are:
Definition
 Rayls
Term
 Which condition between two media interfaces would produce the greatest amount of ultrasound reflected back to the transducer.
Definition
 Large impedance difference
Term
 In soft-tissue _______ makes imaging less angle dependent.
Definition
 Scattering
Term
 Refraction often causes a type of artifact known as:
Definition
 Lateral position error
Term
 The decibel notation is a convenient way to express the _____ between two intensities.
Definition
 Ratio
Term
 Approximately what percent of the incident intensity is reflected at a soft tissue-air interface?
Definition
 100%
Term
 What statement is most correct regarding ultrasound absorption?
Definition
 Absorption is the major part of attenuation
Term
 The attenuation coefficient is expressed in:
Definition
 db/cm/MHz
Term
 In order for a refracted wave to be produced, which of the following conditions must be met at an interface?
Definition
 Oblique incidence, same sound speeds
Supporting users have an ad free experience!