SPI Review 31-150 Flashcards by Alyssa Flores

The following illustration depicts acoustic pressure vs. distance in a medium in which a sound wave is present . What sound parameter is measured by the length of the bar labeled A in the following illustration?
A. Amplitude 
B. Wavelength
C. Pressure 
D. Pulse repetition frequency 
E. Duty factor

B. Wavelength

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The mass you are imaging has a diameter of 35mm. This value can also be expressed as :
A. 350 cm
B. .35cm
C. 3.5cm
D. 35m
E. 3.5m

C. 3.5cm

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Relative measurement of intensity based on a logarithmic scale is expressed in:
A. Newton’s per centimeter squared
B. Watts per centimeter squared 
C. Decibels 
D. Pascals 
E. Neper

C. Decibels

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Which prefix equals 10^-3

A. Micro
B. Milli
C. Mega
D. Centi
E. None of the above

B. Milli

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When you change the transmit frequency, which of the following is altered ?
A. Displacement amplitude of particles in the medium
B. Speed at which the sound wave propagates through the medium
C. # of cycles per second
D. Pulses transmitted per second
E. # of electric impulses applied to the transducer per second

C. # of cycles per second

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While performing Doppler ultrasound examination, you adjust the pulse repetition frequency to 12 kHz. This can also be expressed as :
A. .12Hz
B. 1200 Hz
C. 1.2 MHz
D. 12,000 Hz 
E. 120 MHz

D. 12,000 Hz

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In sound wave propagation, a region of elevated pressure is termed :
A. Compression 
B. Demodulation 
C. Rarefraction
D. Period
E. Resonance

A. Compression

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When you switch from a 2.5 MHz to a 5.0 MHz transducer, the sound wavelength:
A. Doubles
B. Quadruples
C. Halves 
D. Quarters 
E. Is unaffected

C. Halves

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Wavelength depends on a what two factors?
A. Frequency and amplitude 
B. Amplitude and propagation speed
C. Period and frequency 
D. Frequency and propagation speed 
E. Amplitude and intensity

D. Frequency and propagation speed

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Which of the following human tissues has the highest rate of attenuation of an ultrasound wave?
A. Liver
B. Fat
C. Fluid
D. Lung
E. Blood vessels

D. Lung

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The propagation speed for sound is lowest in which of the following biological tissues?
A. Fat
B. Blood
C. Muscle
D. Bone
E. Liver

A. Fat

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Which of the following factors does NOT affect impedance?
A. Stiffness 
B. Density 
C. Propagation speed 
D. Frequency 
E. All of the above affect impedance

D. Frequency

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You are imaging a structure containing two media having the same acoustic impedance. What will occur at the boundary of the two structures?
A. All of the sound will be transmitted
B. All of the sound will be reflected
C. Some of the sound will be refracted
D. Some of the sound will be reflected and some of the sound will be transmitted
E. Most of the sound will be absorbed at the media boundary

A. All of the sound will be transmitted

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What is the purpose of the gel coupling between the transducer and the skin?
A. To reduce heating of the epidermis caused by sound absorption and friction
B. To soften the skin and soothe the patient
C. To provide a medium for sound transmission, since ultrasound does mot propagate through air
D. To reduce the impedance differences between the transducer and the skin
E. To lessen refraction of the sound at the skin surface and improve sound transmission

C. To provide a medium for sound transmission, since ultrasound does mot propagate through air

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The unit of impedance is the:
A. Joule
B. Rayl
C. Watts /cm2
D. Newton’s 
E. Watts /cm

B. Rayl

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With absorption, acoustic energy is converted to :
A. Heat 
B. Microbubbles 
C. Kinetic energy 
D. Decibels 
E. Potential energy

A. Heat

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The intensity transmission coefficient at the interface between two structures equals 1/100. What is the intensity reflection coefficient?
A. 0/100
B. 99/100
C. 1/100
D. 100/100
E. 49/100

B. 99/100

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Which of the following is an example of a Rayleigh scatter?
A. Renal capsule
B. Arterial wall
C. Red blood cell
D. Bowel gas 
E. Femur

C. Red blood cell

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Which of the following sound interactions produced the shadows indicated by the arrows on this image ?
(Page 11)
A. Reflection 
B. Diffraction 
C. Diffusion 
D. Rayleigh scattering 
E. Refraction

E. Refraction

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In order to display a structure on your sonographic image, the sound beam must be reflected at the interface. What is required for sound reflection at the interface of two structures?
A. Oblique incidence at the interface boundary
B. Temperature differences between the two media
C. A difference in the acoustic impedance of the media
D. Different media diameters
E. Different attenuation coefficients

C. A difference in the acoustic impedance of the media

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An example of a specular reflector is:
A. Pericardium 
B. Liver parenchyma
C. Red blood cells
D. Ascites
E. Hematoma

A. Pericardium

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What system control can you adjust to compensate for the effect of sound attenuation in the body?

A. TGC
B. Dynamic range
C. Frame averaging (persistence)
D. Depth
E. Line density

A. TGC

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While imaging a cyst, you notice shadowing posterior to each lateral border of the cyst. What is the source of the shadows ?
A. Redirection of the sound beam at an interface with different propagation speeds and a curved surface
B. Bending of the sound beam due to different media propagation speeds
C. Increased attenuation of the sound beam at the borders of the cyst
D. Lateral misregristration of the cyst due to a multipath artifact
E. Diffraction of the sound beam resulting in a weakened signal at the lateral borders of the cyst

B. Bending of the sound beam due to different media propagation speeds

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B. Bending of the sound beam due to different media propagation speeds

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``` The algebraic summation of waves leading to patterns of minima and maxima is called A. Scattering B. Interference C. Absorption D. Refraction E. Diffusion ```

B. Interference

``` An interaction of echoes that leads to reinforcement rather than to partial or total cancellation is known as: A. Constructive interference B. Refraction C. Destructive interference D. Autocorrelation E. Rarefraction ```

A. Constructive interference

``` Which phenomenon is associated with a pattern produced by a sound beam after passing through a small aperture? A. Scattering B. Absorption C. Diffraction D. Interference E. Diffuse reflection ```

C. Diffraction

``` What sound parameter is determined only by the medium? A. Frequency B. Period C. Intensity D. Propagation speed E. None of the above ```

D. Propagation speed

Snell’s law describes: A. The percentage of reflection at an interference with normal incidence and different densities B. The angle of sound transmission at an interference between media having different propagation speeds C. The amount of attenuation of sound in tissue with depth D. The amount of backscatter from a diffuse reflector E. The angle of sound reflection at an interface with oblique incidence and nonspecular reflection

B. The angle of sound transmission at an interference between media having different propagation speeds

``` As general observation about media in diagnostic sonography, sound propagates faster in material with greater: A. Compressibility B. Acoustic impedance C. Stiffness D. Refractive index E. All of the above ```

C. Stiffness

During the performance of a sonographic examination you would be most likely to encounter refraction in this view: A. Specular reflector B. Curved interference C. Perpendicular incidence D. Rayleigh scatterer E. Refraction is not encountered during an abdominal sonographic exam

B. Curved interference

``` You may observe sound attenuation by all of the following EXCEPT: A. Reflection B. Scattering C. Conversion of sound to heat D. Absorption E. Compression ```

E. Compression

``` When you image sound reflected from a large, smooth interface, you are observing results of : A. Rayleigh scattering B. Diffraction C. Specular reflection D. Diffusion E. Refraction ```

C. Specular reflection

``` During a sonographic examination of a large vessel, a 45* beam-to-vessel angle would be called: A. Normal incidence B. Oblique incidence C. Perpendicular incidence D. Snell’s incidence E. None of the above ```

B. Oblique incidence

What occurs when you image a structure with oblique incidence? A. A very strong reflection will occurs since this is the optimal angel for imaging B. All of the sound will be reflected due to the poor scanning angle C. All of the sound will be transmitted due to poor scanning angle D. The angle of reflection will be oriented away from the transducer, resulting in decreased visualization of the structure E. The amount of scattering will be reduced artifactual echoes

D. The angle of reflection will be oriented away from the transducer, resulting in decreased visualization of the structure

``` The shadow depicted in this image of a renal stone is primarily a result of the following sound tissue interaction: (page 15) A. Reflection B. Refraction C. Destructive interference D. Cavitation E. Diffraction ```

A. Reflection

Which of the following statements regarding the effect of frequency on Rayleigh scattering is TRUE? A. The amount of scattering is not affected by frequency B. Scattering intensity doubles if frequency is doubled C. Doubling the frequency results in having the scattering intensity D. Doubling the frequency results in quartering the scattering intensity E. Scattering intensity is proportional to frequency raised to the fourth power

E. Scattering intensity is proportional to frequency raised to the fourth power

``` What term describes the hyperechoic region (arrow) seen beneath this complex structure? Pg 16 A. Acoustic enhancement B. Acoustic shadowing C. Reverberation D. Refraction E. Acoustic impedance ```

A. Acoustic enhancement

The hyperechoic region in the previous illustration results from:(pg 16) A. Increased acoustic velocity through a fluid-filled structure B. Decreased attenuation through a fluid-filled structure C. Decreased sound absorption in the region distal to the fluid-filled structure D. A high acoustic impedance mismatch between the cyst and adjacent tissue E. Bending of the sound beam due to oblique incidence

B. Decreased attenuation through a fluid-filled structure

What determines acoustic impedance? A. Frequency and propagation B. Frequency and interface size C. Density and propagation speed of the medium D. Angle of incidence and media propagation speed E. Frequency and media density

C. Density and propagation speed of the medium

Diagnostic ultrasound is limited in its diagnostic application to the adult brain because: A. The speed of sound in the brain is much faster than that in soft tissue, resulting in a range artifact B. Nearly all of the sound is transmitted at the interface between bone and soft tissue with no reflection to create an image C. Diffraction of the sound beam occurs because of the irregular surface of the brain , resulting in little transmission of sound through the cranial interface D. Bending of the sound beam due to refraction results in a multipath artifact that distorts the image, making it nondiagnostic at high frequencies E. The great acoustic impedance mismatch between the cranium and soft tissue causes most of the sound to be reflected at the interface

E. The great acoustic impedance mismatch between the cranium and soft tissue causes most of the sound to be reflected at the interface

Which of the following describes diffuse reflection? A. The reflected beam is scattered in various directions B. The reflected frequency is altered by the Doppler effect C. The reflected beam is amplified by the focusing effect of scatters D. The reflected beam is weakened by the large acoustic impedance mismatch at the tissue interface E. There is no reflection at a tissue interface because of a disorganized transmit beam

A. The reflected beam is scattered in various directions

According to Snell’s Law, the angle of transmission is related to the incident beam angle and: A. The amount of acoustic impedance mismatch at an interface B. The change in frequency that occurs at an interface C. One-half the angle of incidence D. The relative speeds of sound in the two media E. The percentage of diffraction distal to the interface

D. The relative speeds of sound in the two media

``` Which of the following interactions of sound and tissue decreases the intensity of the transmitted beam? A. Absorption B. Reflection C. Scattering D. Conversion of sound to heat E. All of the above ```

E. All of the above

What is the relationship of frequency to absorption? A. If frequency is halved, absorption is doubled B. If frequency is doubled, absorption is doubled C. If frequency is doubled, absorption is halved D. If frequency is halved, absorption is quartered E. The rate of sound absorption is not frequency-dependent

B. If frequency is doubled, absorption is doubled

``` What term is used to describe the reduction in the intensity of sound as it propagates through tissue? A. Diffraction B. Refraction C. Reflection D. Absorption E. Attenuation ```

E. Attenuation

``` Another term for nonspecular reflection is: A. Destructive interference B. Refraction C. Diffraction D. Scattering E. Absorption ```

D. Scattering

``` While performing a sonographic exam, you encounter the following interfaces. Which will produce the weakest reflected signal ? A. Organ parenchyma/fluid B. Organ parenchyma/air C. Organ parenchyma/ organ parenchyma D. Organ parenchyma/bone E. Organ parenchyma/ligament ```

C. Organ parenchyma/ organ parenchyma

``` During a diagnostic ultrasound examination, you encounter all of the interactions of ultrasound and tissue listed below. Which one will NOT cause a redirection of part of the ultrasound energy? A. Reflection B. Scattering C. Divergence D. Absorption E. Refraction ```

D. Absorption

As you perform a sonographic exam, you switch from a 3.5 MHz transducer to a 7.0 MHz transducer to image a superficial structure. Compared to the 3.5 MHz transducer, what will the 7.0 MHz attenuation rate and wavelength be? A. Double the attenuation rate, one-half the wavelength B. Double the attenuation rate, double the wavelength C. One-fourth the attenuation rate , one-half the wavelength D. One-half the attenuation rate, double the wavelength E. One-half the attenuation rate, one-fourth the wavelength

A. Double the attenuation rate, one-half the wavelength

You are scanning a large mass that is composed primarily of fat. Which of the following are you most likely to encounter? A. Posterior acoustic shadowing caused by increased attenuation through the fat B. Axial misregistration of objects distal to the mass on the screen due to the slower propagation speed through fat C. Lateral misregistration of the mass on the screen because of refraction D. Total reflection of the sound beam caused by large acoustic impedance mismatch E. Diffraction of the sound beam due to a virtual small aperture through the mass

B. Axial misregistration of objects distal to the mass on the screen due to the slower propagation speed through fat

What two conditions must be present to cause refraction of a sound wave? A. Perpendicular incidence and identical media propagation B. Perpendicular incidence and reflector size smaller than one wavelength C. Oblique incidence and different media propagation speeds D. Oblique incidence and reflector size smaller than one wavelength E. Normal incidence and reflector size smaller than one wavelength

C. Oblique incidence and different media propagation speeds

The transducer you are using transmits wide - bandwidth pulses whose frequency content is 2.5 MHz. Which of the following most correctly describes the reflected echo signals after they have traversed the tissue? A. The echo signals will be shifted down in frequency due to the increased attenuation of higher frequencies B. The echo signals will be of reduced intensity but will have the same frequency content as the transmitted beam C. The echo signals will be shifted upward in frequency due to the increased absorption of the lower frequencies D.only the center frequency component of the bandwidth will be reflected back to the transducer E. The echo signal frequency content will be identical to that of the transmitted beam

A. The echo signals will be shifted down in frequency due to the increased attenuation of higher frequencies

When the sound beam is refracted during a sonographic examination, which of the following might you detect on the ultrasound image? A. Axial misregistration B. Lateral misregistration C. Reverberations posterior to a reflector D . Enhancement of a reflector E. Electrical interference

B. Lateral misregistration

What can you do to enhance the visibility of a specular reflector? A. Scan with the lowest possible frequency B. Scan with oblique incidence C. Scan with perpendicular incidence D. Increase the distance to the reflector E. Scan with an incident angle of 45*

C. Scan with perpendicular incidence

``` What interaction of ultrasound and tissue is primarily responsible for imaging the internal structure of organs ? A. Specular reflection B. Refraction C. Diffraction D. Destructive interference E. Scattering ```

E. Scattering

``` During production of a sonogram, you image the following structures. Which is the MOST attenuating? A. Blood B. Bile C soft tissue D. Calcification E. Muscle ```

D. Calcification

``` What sound-tissue interaction is necessary to form an ultrasound image? A. Rarefraction B. Refraction C. Reflection D. Diffraction E. Interference ```

C. Reflection

``` For soft tissue, one of the factors responsible for determining acoustic impedance is: A.attenuation B. Frequency C. Absorption D. Density E. Amplitude ```

D. Density

When you image a structure that is a specular reflector, the strength of the received signal depends on the following two factors : A. Difference in acoustic impedance and angle of incidence B. Difference in acoustic velocity and interface size C. Difference in acoustic velocity and motion reflector D. Angle of incidence and tissue temperature E. Bulk modulus and interface size

A. Difference in acoustic impedance and angle of incidence

``` Attenuation of the sound beam increases with increasing: A. Path length B. Absorption C. Frequency D. Scattering and reflection E. All of the above ```

E. All of the above

``` You are imaging a rounded mass with irregular borders. The mass has a much slower propagation speed than surrounding tissue. What sound-tissue interaction will be encountered as the ultrasound propagates through this interface ? A. Refraction B. Reflection C absorption D. Scattering E. All of the above ```

E. All of the above

``` You are imaging a structure that is highly attenuating. Which imaging effect do you expect to encounter? A. Enhancement B. Increased penetration C. Shadowing D. Refraction E. Increased acoustic speckle ```

C. Shadowing

When you are educating your patient about the sonographic exam, sound travels through air from your mouth to patients ears . Which of the following is true regarding the speed of sound travel through air? A. The speed of sound in air is greater than the speed of light B. The speed of sound in air is greater than the speed of sound in soft tissue C. The speed of sound in air is not predictable D. The speed of sound in air is slower than the speed of sound in soft tissue E. The speed of sound in air is equal to the speed of sound in soft tissue

D. The speed of sound in air is slower than the speed of sound in soft tissue

``` In the following illustration, if the propagation speed is unchanged at the interface, which most correctly describes the sound-tissue interaction that will take place when the ultrasound wave strikes the depicted interface? (Pg21) A. Specular reflection B. Scattering C. Diffraction D. Refraction E. None of the above ```

B. Scattering

You have increased the transmit power while performing a pelvic ultrasound examination. This action increases which of the following? A. Penetration B. Acoustic power C. Image brightness D. Voltage applied to the transducer elements E. All of the above

E. All of the above

If sound waves of 3 MHz, ,5 MHz, and 10 MHz are transmitted through the Sam section of anatomy , reflections from which frequency would reach the transducer first ? A. 3 MHz B. 5 MHz C. 10 MHz D. Reflections from all three frequencies would have nearly identical transit times E. It is not possible to predict which will arrive first

D. Reflections from all three frequencies would have nearly identical transit times

What would you do if the image does not show adequate penetration and the far field displays noise instead of tissue? A. Turn on spatial compound imaging B. Move the focal position to a more superficial location C. Use an acoustic stand-off pad D. Increase TGC E. Decrease transmit frequency

E. Decrease transmit frequency

``` For pulsed ultrasound, which of the following factors determines the frequency of the sound wave? A. Pulse repetition frequency B. Transmitter frequency C. Area of the transducer elements D. Pressure applied to the transducer E. All of the above ```

B. Transmitter frequency

You have decreased the acoustic power by -3dB. Which of the following most accurately describes this adjustment? A. The intensity had been quadrupled B. The intensity had been quartered C. The intensity has been increased 10 times D. The intensity has been halved E. The intensity has not been altered

D. The intensity has been halved

Which of the following describes sound propagation through a vacuum? A. Sound travels as transverse waves through a vacuum B. When sound travels through a vacuum , the propagation speed increases to 3,300,000 m/s C. Sound travels at the speed of light in a vacuum D. Sound propagation is random in a vacuum E. Sound cannot travel through a vacuum

E. Sound cannot travel through a vacuum

``` When your pt asks you how much longer the ultrasound test will take , his voice is in the audible frequency range. Which of the following frequencies is in the audible frequency range ? A. 100 MHz B. 10 kHz C. 10 Hz D. 10,000 MHz E. 1,000,000 Hzn ```

B. 10 kHz

``` The maximum cyclical change in a quantity is known as : A. Amplitude B. Pressure C. Power D. Intensity E. Decibel ```

A. Amplitude

``` Bulk modulus is closely related to which of the following quantities? A. Attenuation B. Frequency C. Wavelength D. Volume E. Stiffness ```

E. Stiffness

Which most correctly describes sound propagation in a medium? A. In sound propagation, a molecule travels from one end of the medium to another B. Molecules oscillate back and fourth to propagate sound waves but do not move from one end of the medium to another . C. A molecule does not vary its position as a sound wave travels D. Each molecule expands and contracts to propagate a sound wave through a medium E. Sound waves cannot travel through a medium

B. Molecules oscillate back and fourth to propagate sound waves but do not move from one end of the medium to another .

``` Which of the following terms denotes the time it takes for one cycle to occur ? A. Frequency B. Amplitude C. Wavelength D. Period E. Pressure ```

D. Period

``` If the # of cycles in a pulse is increased but the wavelength remains the same , which of the following is true ? A. The frequency is increased B. The propagation speed is increased C. The pulse duration is increased D. The period is decreased E. The bulk modulus is decreased ```

C. The pulse duration is increased

``` Which of the following is most likely also to decrease beam intensity? A. Increasing acoustic output B. Decreasing receiver gain C. Increasing focusing D. Increasing beam area E. Increasing amplitude ```

D. Increasing beam area

``` Which of the following best characterizes an ultrasound wave in a human tissue? A. Mechanical longitudinal wave B. Radioactive wave C. Transverse rarefractional wave D. Electromagnetic wave E. Electronic piezoelectric wave ```

A. Mechanical longitudinal wave

``` The regions of low pressure and density that are formed during sound propagation are termed: A. Compressions B. Shear waves C. Rarefactions D. Cavitation E. Bulk modulus ```

C. Rarefactions

``` The sound propagation speed is used to calibrate range-measuring circuits on diagnostic sonography instruments is : A. 1.54 m/a B. 1560 mm/s C. 1.46mm/ us D. 1540 m/s E. 146,000 cm/s ```

D. 1540 m/s

``` Which of the following properties would result in increased propagation speed of sound through a medium? A. Increased stiffness B. Increased density C. Increased frequency D. Increased distance E. Increased amplitude ```

A. Increased stiffness

``` Which of the following frequencies is considered to be ultrasound? A. 2000 Hz B. 20 Hz C. 2 MHz D. 200Hz E. 2Hz ```

C. 2 MHz

``` You are performing a sonographic exam on a large pt. Which transducer would provide the least amount of signal attenuation? A. 2.5 MHz B. 3.5 MHz C. 5.0 MHz D. 7.5 MHz E. 10 MHz ```

A. 2.5 MHz

``` Which of the following increases as frequency increases ? A. Absorption B. Scattering C. Attenuation D. A and C only E. All of the above ```

E. All of the above

Which statement about the two pulse trains displayed below is true ? Each represents a signal vs time ? Pg 26 A. A has a lower frequency than B B. B has a longer period than A C. A has a shorter wavelength than B D. A has a better axial resolution than B E. A has a shorter spatial pulse length than B

A. A has a lower frequency than B

``` What is the velocity of an ultrasound wave in a bone ? A. 333 m/s B. 8059 m/s C. 1540 m/s D. 4080 m/s E. 1240 m/s ```

D. 4080 m/s

The speed of sound is defined as the: A. Speed of the vibrating particles in the medium B. Speed at which the sound wave propagates through the medium C. # of cycles per second of the vibrating particles D. Inverse of the frequency E. Speed of the electric impulse applied to the piezoelectric element

B. Speed at which the sound wave propagates through the medium

A longitudinal wave is characterized by: A. A wave that demonstrates only sagittal imaging planes B. Randomized particle motion C. A constant acoustic velocity of 1540 m/s D. Particle motion occurring in the same direction as propagation E. Particle morning occurring perpendicular to the direction of propagation

D. Particle motion occurring in the same direction as propagation

``` Wavelength is measured in: A. Hertz B. Microseconds C. Millimeters D. Rayls E. Newtons ```

C. Millimeters

``` What term refers to regions of decreased particle density in a sound beam? A. Attenuation B. Transmission C. Compression D. Rarefaction E. Reverberation ```

D. Rarefaction

``` 10^-3 equals: A. 1000 B. 1/1000 C. 1/10,000 D. 100 E. 10 ```

B. 1/1000

``` Which of the following represents the number 1234 in scientific notation? A. .1234 B. .1234x10^3 C. 1234 x10^1 D. 1234 x10^-1 E. 1.234x 10^3 ```

E. 1.234x 10^3

``` One MHz equals : A. 10^3 Hz B. 10^-3 Hz C. 10^6 Hz D. 10^-6 Hz E. 10^9 Hz ```

C. 10^ 6 Hz

``` Terms used to describe the strength of the sound beam include : A. Amplitude and impedance B. Amplitude and wavelength C. Amplitude and intensity D. Intensity and impedance E. Frequency and impedance ```

C. Amplitude and intensity

``` You are imaging with a 5 MHz linear array transducer . What sound parameter stays constant as the beam propagates through the tissue? A. Frequency B. Intensity C. Amplitude D. Wavelength E. None of the above ```

E. None of the above

``` Ultrasound propagation velocity depends on: A. Amplitude and frequency B. Impedance and attenuation C. Density and compressibility D. Dynamic range and compression E. Impedance and density ```

C. Density and compressibility

``` You notice that the image in the far field is less bright compared to the near field . This is due to : A. Sound attenuation B. Propagation speed variation C. Refraction D. Diffraction E. The Doppler effect ```

A. Sound attenuation

Acoustic impedance: A. Is independent of the speed of sound B. Is inversely proportional to the density C. Is greater in gas than in metal D. Equals density times the propagation speed E. Is independent of the density

D. Equals density times the propagation speed

``` What determines the speed of sound ? A. Frequency of sound wave B. Intensity of a sound wave C. Attenuation of a sound wave D. Reflection of a sound wave E. Medium through which sound wave passes ```

E. Medium through which sound wave passes

You will NOT see refraction in the sonographic image if: A. The sound beam strikes an interface at an angle of greater than 45* B. The sound beam is perpendicular to the interference C. The sound beam is 45* to the Interface D. The sound beam changes propagation speed at the interface E. The sound beam strikes an interface at an angle of less than 45*

B. The sound beam is perpendicular to the interference

``` The rate of sound attenuation is lowest in : A. Air B. Water C. Liver D. Bone E. Lung ```

B. Water

When you perform a Doppler exam , the frequency of the transmitted signal is determined by: A. Backing material B. Attenuation factor of the tissue C. Bandwidth D. The frequency of the electric signal applied to the transducer E. Amplitude

D. The frequency of the electric signal applied to the transducer

``` Power divided by the beam area is equal to the: A. Probe angle B. Speed of sound C. Intensity D. Attenuation E. Amplitude ```

C. Intensity

``` Axial resolution is determined chiefly by: A. Beam width B. Transducer diameter C. Pulse duration D. Attenuation coefficient E. Intensity ```

C. Pulse duration

Choosing two benefits of tissue harmonic imaging A. Grating lobe artifacts are reduced and lateral resolution is improved B. Axial and lateral resolutions are improved C. Contrast and axial resolutions are improved D. Penetration is improved and axial resolution is improved E. Penetration is improved and contrast resolution is improved

A. Grating lobe artifacts are reduced and lateral resolution is improved

``` Acoustic impedance increases with which of the following? A. Increased tissue density B. Increased propagation speed C. Increased transducer frequency D. A and B E. All of the above ```

D. A and B

``` When you adjust the pulse repetition frequency, you are changing : A. The number of pulses per line B. The number of pulses per frame C. The number of pulses per second D. The number of wavelengths per second E. The number of wavelengths per pulse ```

C. The number of pulses per second

Which of the following would increase the spatial pulse length? A. Increased PRF B. Decreased # of transmit pulses per frame C. Increased # of transmit pulses per second D. Increased number of transmit pulses per line E. Increased number of cycles per pulse

E. Increased number of cycles per pulse

``` Doppler pulses used for diagnostic purposes are typically ______________ cycles long: A. 0-2 B. 2-3 C. 4-5 D. 5-30 E. Greater than 100 ```

D. 5-30

``` The time that it takes for one pulse to occur is known as the : A. Duty factor B. Spatial pulse length C. Wavelength D. Pulse repetition frequency E. Pulse duration ```

E. Pulse duration

``` The length of space over which one cycle occurs is known as the : A. Duty factor B. Spatial pulse length C. Wavelength D. Pulse repetition frequency E. Pulse duration ```

C. Wavelength

``` Bandwidth refers to : A. Number of cycles per 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 second ```

B. Range of frequencies in a pulse

``` When sound strikes a specular reflector at an oblique angle, the angle of reflection is: A. Equal to the angle of incidence B. Greater than the angle of incidence C. Less than the angle of incidence D. Twice that of the angle of incidence E. The cosine of the angle of incidence ```

A. Equal to the angle of incidence

Which describes constructive interference? A. Sound waves are in phase and resulting amplitude is increased B. Sound waves are in phase and resulting amplitude is decreased C. Sound waves are out of phase and resulting amplitude is increased D. Sound waves are out of phase and resulting in amplitude is decreased E. None of the above

A. Sound waves are in phase and resulting amplitude is increased

``` The dark area indicated by the arrow in this image is primarily due to: (pg31) A. Beam refraction B. Beam enhancement C. Destructive interference D. Increased attenuation E. All of the above ```

D. Increased attenuation

``` Which sound beam frequency would exhibit the greatest intensity loss with increasing depth? A. 10 MHz B. 8 MHz C. 5 MHz D. 3 MHz E. 2 MHz ```

A. 10 MHz

``` Interference patterns of reflected waves cause : A. Acoustic speckle B. Acoustic enhancement C. Rarefaction D.volume averaging E. All of the above ```

A. Acoustic speckle

``` Attenuation of the sound beam is affected by: A. Absorption B. Scattering C. Reflection D. Propagation speed E. A, B, and C ```

E. A, B, and C

``` The transfer of acoustic energy into heat is termed: A. Scattering B. Diffusion C. Diffraction D. Absorption E. Refraction ```

D. Absorption

SPI Review 31-150 Flashcards

(120 cards)