DAVIES SPI: II. Physical Principles (20% of
ARDMS)
10^(-3) equals:
A. 1000
B. 1/a thousand
C. 1/10,000
D. A hundred
E. 10 - ANS-B. 1/a thousand
A longitudinal wave is characterised with the aid of:
A. A wave that demonstrates simplest sagittal imaging planes
B. Randomized particle motion
C. A constant acoustic speed of 1540 m/s
D. Particle motion taking place inside the identical course as propagation
E. Particle movement happening perpendicular to the path of propagation - ANS-D. Particle
movement taking place within the same path as propagation
<Particle motion that is perpendicular to the direction of propagation characterizes a transverse
wave>
According to Snell's law the perspective of transmission is associated with the incident beam
angle and:
A. The quantity of acoustic impedance mismatch at an interface
B. The change in frequency that takes place at an interface
C. One-half of of the perspective of prevalence
D. The relative speeds of sound inside the two media
E. The percentage of diffraction distal to the interface - ANS-D. The relative speeds of sound in
the media
<Snell's law dictates the angle of transmission that will occur at an interface with refraction of
the sound beam. Refraction (bending) of the sound beam occurs whenever there is oblique
incidence and different propagation speeds between two media>
Acoustic impedance will increase with which of the following?
,A. Increased tissue density
B. Increased propagation velocity
C. Increased transducer frequency
D. A and B
E. All of the above - ANS-D. A and B
Acoustic impedance:
A. Is unbiased of the speed of sound
B. Is inversely proportional to the density
C. Is extra in gasoline than in metallic
D. Equals density times the propagation pace
E. Is independent of the density - ANS-D. Equals density instances the propagation pace
< Z=rc >
An echo from which one of the following sound reflectors is maximum depending on the angle of
occurrence?
A. Rayleigh scatterer
B. Diffuse reflector
C. Specular reflector
D. Acoustic scatterer
E. Nonspecular reflector - ANS-C. Specular reflector
<With specular reflection, the angle of reflection is equal to the angle of incidence. So, in order
to get most of the reflected sound to be angled back at the transducer, the transducer must be
oriented so that the sound will strike the interface perpendicularly. That is why we get the best
images of the kidney, aorta, and similar structures when we have them positioned horizontally
on the ultrasound image>
An example of a specular reflector is:
A. Pericardium
B. Liver parenchyma
C. Red blood cells
D. Ascites
E. Hematoma - ANS-A. Pericardium
<A specular reflector is a large, smooth interface such as the renal capsule, diaphragm, or
pericardium. Specular reflection is primarily responsible for the bright interfaces seen at organ
boundaries>
,An interplay of echoes that leads to reinforcement in place of to partial or general cancellation is
referred to as:
A. Constructive interference
B. Refraction
C. Destructive interference
D. Autocorrelation
E. Rarefaction - ANS-A. Constructive interference
Another time period for nonspecular reflection is:
A. Destructive interference
B. Refraction
C. Diffraction
D. Scattering
E. Absorption - ANS-D. Scattering
<Specular reflection occurs when the interface is large and smooth: Nonspecular reflection or
scattering occurs when the interface is small, less than several wavelengths across>
As a trendy remark about media in diagnostic sonography sound propagates faster in materials
with more:
A. Compressibility
B. Acoustic impedance
C. Stiffness
D. Refractive index
E. All of the above - ANS-C. Stiffness
As you perform a sonogram you switch from a three.Five MHz transducer to a 7.Zero MHz
transducer to photograph a superficial structure. Compared to the 3.5 MHz transducer what is
going to be the 7.0 MHz attenuation fee and wavelength be?
A. Double the attenuation rate, one-half the wavelength.
B. Double the attenuation price, double the wavelength.
C. One-fourth the attenuation charge, one-half the wavelength.
D. One-half of the attenuation charge, double the wavelength.
E. One-half of the attenuation price, one-fourth the wavelength. - ANS-A. Double the attenuation
fee, one-half of the wavelength
<If frequency is doubled, the rate of attenuation is doubled but the wavelength is halved.
Remember: As frequency increases, wavelength decreases, improving resolution but
decreasing penetration because of increased sound absorption>
, Attenuation of the sound beam will increase with increasing:
A. Path period
B. Absorption
C. Frequency
D. Scattering and reflection
E. All of the above - ANS-E. All of the above
<The attenuation coefficient is the degree of attenuation for each centimeter of sound
propagation. Anything that increases attenuation will increase the attenuation coefficient>
Attenuation of the sound beam is tormented by:
A. Absorption
B. Scattering
C. Reflection
D. Propagation velocity
E. A, B and C - ANS-E. A, B and C
<Propagation speed does not affect attenuation of the sound beam>
Axial decision is determine chiefly by:
A. Beam width
B. Transducer diameter
C. Pulse length
D. Attenuation coefficient
E. Intensity - ANS-C. Pulse duration
<The shorter the pulse duration, the better the axial resolution>
Bandwidth refers to:
A. Number of cycles in line with pulse
B. Range of frequencies in a pulse
C. Rate of pulse repetition frequency
D. Range of pulses in a frame
E. Number of wavelengths in one 2nd - ANS-B. Range of frequencies in a pulse
Bulk modulus is carefully related to which of the following features?
A. Attenuation
B. Frequency
C. Wavelength
ARDMS)
10^(-3) equals:
A. 1000
B. 1/a thousand
C. 1/10,000
D. A hundred
E. 10 - ANS-B. 1/a thousand
A longitudinal wave is characterised with the aid of:
A. A wave that demonstrates simplest sagittal imaging planes
B. Randomized particle motion
C. A constant acoustic speed of 1540 m/s
D. Particle motion taking place inside the identical course as propagation
E. Particle movement happening perpendicular to the path of propagation - ANS-D. Particle
movement taking place within the same path as propagation
<Particle motion that is perpendicular to the direction of propagation characterizes a transverse
wave>
According to Snell's law the perspective of transmission is associated with the incident beam
angle and:
A. The quantity of acoustic impedance mismatch at an interface
B. The change in frequency that takes place at an interface
C. One-half of of the perspective of prevalence
D. The relative speeds of sound inside the two media
E. The percentage of diffraction distal to the interface - ANS-D. The relative speeds of sound in
the media
<Snell's law dictates the angle of transmission that will occur at an interface with refraction of
the sound beam. Refraction (bending) of the sound beam occurs whenever there is oblique
incidence and different propagation speeds between two media>
Acoustic impedance will increase with which of the following?
,A. Increased tissue density
B. Increased propagation velocity
C. Increased transducer frequency
D. A and B
E. All of the above - ANS-D. A and B
Acoustic impedance:
A. Is unbiased of the speed of sound
B. Is inversely proportional to the density
C. Is extra in gasoline than in metallic
D. Equals density times the propagation pace
E. Is independent of the density - ANS-D. Equals density instances the propagation pace
< Z=rc >
An echo from which one of the following sound reflectors is maximum depending on the angle of
occurrence?
A. Rayleigh scatterer
B. Diffuse reflector
C. Specular reflector
D. Acoustic scatterer
E. Nonspecular reflector - ANS-C. Specular reflector
<With specular reflection, the angle of reflection is equal to the angle of incidence. So, in order
to get most of the reflected sound to be angled back at the transducer, the transducer must be
oriented so that the sound will strike the interface perpendicularly. That is why we get the best
images of the kidney, aorta, and similar structures when we have them positioned horizontally
on the ultrasound image>
An example of a specular reflector is:
A. Pericardium
B. Liver parenchyma
C. Red blood cells
D. Ascites
E. Hematoma - ANS-A. Pericardium
<A specular reflector is a large, smooth interface such as the renal capsule, diaphragm, or
pericardium. Specular reflection is primarily responsible for the bright interfaces seen at organ
boundaries>
,An interplay of echoes that leads to reinforcement in place of to partial or general cancellation is
referred to as:
A. Constructive interference
B. Refraction
C. Destructive interference
D. Autocorrelation
E. Rarefaction - ANS-A. Constructive interference
Another time period for nonspecular reflection is:
A. Destructive interference
B. Refraction
C. Diffraction
D. Scattering
E. Absorption - ANS-D. Scattering
<Specular reflection occurs when the interface is large and smooth: Nonspecular reflection or
scattering occurs when the interface is small, less than several wavelengths across>
As a trendy remark about media in diagnostic sonography sound propagates faster in materials
with more:
A. Compressibility
B. Acoustic impedance
C. Stiffness
D. Refractive index
E. All of the above - ANS-C. Stiffness
As you perform a sonogram you switch from a three.Five MHz transducer to a 7.Zero MHz
transducer to photograph a superficial structure. Compared to the 3.5 MHz transducer what is
going to be the 7.0 MHz attenuation fee and wavelength be?
A. Double the attenuation rate, one-half the wavelength.
B. Double the attenuation price, double the wavelength.
C. One-fourth the attenuation charge, one-half the wavelength.
D. One-half of the attenuation charge, double the wavelength.
E. One-half of the attenuation price, one-fourth the wavelength. - ANS-A. Double the attenuation
fee, one-half of the wavelength
<If frequency is doubled, the rate of attenuation is doubled but the wavelength is halved.
Remember: As frequency increases, wavelength decreases, improving resolution but
decreasing penetration because of increased sound absorption>
, Attenuation of the sound beam will increase with increasing:
A. Path period
B. Absorption
C. Frequency
D. Scattering and reflection
E. All of the above - ANS-E. All of the above
<The attenuation coefficient is the degree of attenuation for each centimeter of sound
propagation. Anything that increases attenuation will increase the attenuation coefficient>
Attenuation of the sound beam is tormented by:
A. Absorption
B. Scattering
C. Reflection
D. Propagation velocity
E. A, B and C - ANS-E. A, B and C
<Propagation speed does not affect attenuation of the sound beam>
Axial decision is determine chiefly by:
A. Beam width
B. Transducer diameter
C. Pulse length
D. Attenuation coefficient
E. Intensity - ANS-C. Pulse duration
<The shorter the pulse duration, the better the axial resolution>
Bandwidth refers to:
A. Number of cycles in line with pulse
B. Range of frequencies in a pulse
C. Rate of pulse repetition frequency
D. Range of pulses in a frame
E. Number of wavelengths in one 2nd - ANS-B. Range of frequencies in a pulse
Bulk modulus is carefully related to which of the following features?
A. Attenuation
B. Frequency
C. Wavelength
