SPI Boards

Which operator control most directly adjusts the intensity of the transmitted pulse? a. receiver gain b. depth of scanning c. acoustic output (transmit) power d. TGC e. PRF

TGC

A sound beam starts off with an intensity of 200 and ends with an intensity of 20. What is the change in intensity in dB? a. -10 dB b. 10 dB c. 20 dB d. -3 dB

a. -10 dB

Listed are transducer axial resolutions. Which transducer has the best axial resolution? a. .15 mm b. .25 mm c. .4 mm d. .6 mm

a. .15 mm

Thermally induced biologic effects should be preventable by avoiding a local tissue temperature increase exceeding: a. 1 degree C 2. 4 degrees C 3. 10 degrees C 4. 95 degrees C 5. none; thermal effects have no threshold

a. 1 degree C

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

You are performing a sonographic exam on a large patient. Which transducer would provide the least amount of signal attenuation? a. 2.5 MHz b. 3.5 MHz c. 5 MHz d. 7.5 MHz e. 10 MHz

a. 2.5 MHz

You have selected a wide-bandwidth transducer with multiple transmit frequencies to perform a sonographic examination. Which transmit frequency should you select for maximum penetration? a. 3 MHz b. 3.5 MHz c. 4 MHz d. 5 MHz e. Penetration is not affected by frequency

a. 3 MHz

If we double the amplitude, how many times does the power increase? a. 4 b. 8 c. 2 d. 16 e. does not change

a. 4

Interference patterns of reflected waves cause waves cause: a. Acoustic speckle b. Acoustic enhancement c. Rarefaction d. Volume averaging e. All of the above

a. Acoustic speckle

Which of the following tissues has the highest propagation speed? a. Bone b. Air c. Tendon d. Fat e. Blood

a. Bone

Choose 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

Which intensity descriptor has the lowest numeric value for the characterization of a pulse-wave ultrasonic field? a. SATA b. SPTA c. SATP d. SPTP E. These intensity descriptors are used only for continuous-wave ultrasound

a. SATA

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 signal will be shifted down in frequency due to increased attenuation of higher frequency 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 at the transducer e. The echo signal frequency content will be identical to that of the transmitted beam

a. The echo signal will be shifted down in frequency due to increased attenuation of higher frequency

The motion of particles in a fluid is sometimes observed in an intense ultrasound beam. This is termed: a. acoustic streaming b. transient cavitation c. thermal interation d. rarefraction e. compression

a. acoustic streaming

You are building a transducer and want to decrease the length of the pulse. Do you want... a. more dampening b. less dampening c. lower frequency d. higher amplitude

a. more dampening

A transducer with an axial resolution of 4mm encounters two reflectors that are 3mm apart. What will appear on the display? a. one b. two

a. one

To minimize the risk of biologic effects of ultrasound to the fetus, which imaging mode tradeoff would be most acceptable? a. use M-mode instead of pulsed-wave doppler to measure the fetal heart rate b. use color doppler instead of power doppler to image the umbilical cord c. use pulse-wave doppler instead of power doppler to evaluate the fetal heart d. use harmonics instead of fundamental to image the fetal spine e. all of them

a. use M-mode instead of pulsed-wave doppler to measure the fetal heart rate

Axial resolution can be improved by decreasing the... a. wavelength b. focal depth c. frequency d. PRF

a. wavelength decreasing the wavelength increases the frequency

If the SPL equals .6mm and the space between the reflectors equals .2mm then will there be one reflector or two? a. one b. two

a.one Axial resolution = .3mm and the reflectors have to have a distance equal to or greater than the axial resolution to appear as 2

The worst axial resolution can be expected from a pulse-echo instrument with which of the following characteristics.. a. 1.0 MHz, 2 cycles/pulse b. 1.0 MHZ, 4 cycles/pulse c. 2.5 MHz, 4 cycles/pulse d. 4 MHz, 4 cycles/pulse e. 4 MHz, 2 cycles/pulse

b. 1.0 MHz, 4 cycles/pulse

You are using a 5 MHz, 40 mm linear array transducer to image a structure. What is the width of the image? a. 20 mm b. 40 mm c. 60 mm d. 80 mm e. 120 mm

b. 40 mm

If we triple the amplitude, how many times does the power increase? a. 3 b. 9 c. 6 d. 12 e. does not change

b. 9

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

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 a 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

During the performance of a sonographic examination you would be most likely to encounter refraction in this view: a. Specular reflector b. Curved interface c. Perpendicular incidence d. Rayleigh scatterer e. Refraction is not encountered during an abdominal sonographic exan

b. Curved interface

Acoustic enhancement results from: a. Increased acoustic velocity through a fuild-filled structure b. Decreased attenuation through a fluid-filled strucutre c. Decreased sound absorption in the region distal to the fuild-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 strucutre

Which of the following tissues has the lowest propagation speed? a. Bone b. Fat c. Liver d. Blood e. Water

b. Fat

What potential bioeffect occurs through absorption of sound energy by tissue? a. Cavitation b. Heating c. Attenuation d. Reflection e. Refraction

b. Heating

What is the relationship of frequency to absorption? a. If the frequency is halved, absorption is doubled b. If the 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 the frequency is doubled, absorption is doubled

When the sound beam is refracted during a sonographic examination, which of the following might you defect 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

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 forth 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 forth to propagate sound waves but do not move from one end of the medium to another.

During a sonographic examination of a large vessel, a 45 degree 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

Which of the following tissues has the highest propagation speed? a. Water b. Tendon c. Kidney d. Muscle e. Lung

b. Tendon

While imaging a cyst, you notice shadowing posterior to each lateral boarder of the cyst. What is the source of the shadows? a. Redirection of the sound bean 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 a the boards of the cyst d. lateral misregistration of the cyst due to a multipath artifact e. diffraction of the sound beam resulting in a weakened signal at the lateral boarders of the cyst

b. bending of the sound beam due to different media propagation speeds

You are performing a sonographic examination with a wide-bandwidth transducer. The advantage you obtain with this transducer compared to a narrow-band transducer is: a. decreased acoustic power output b. improved axial resolution c. improved lateral resolution d. improved focusing e. wide-bandwidth transducers can be autoclaved

b. improved axial resolution

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. interface

You are building a transducer and you want to increase the length of the pulse. Do you want... a. more dampening b. less dampening c. lower frequency d. higher amplitude

b. less dampening

What sonographic application had the lowest FDA-approved SPTA values? a. cardiac b. ophthalmic c. peripheral vascular d. fetal imaging e. abdominal

b. ophthalmic

Snell's law describes: a. the percentage of reflection at an interface with normal incidence and different densities b. the angle of sound transmission at an interface between media having different propagation speeds c. the amount of attenuation of sound in tissue with dept 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 interface between media having different propagation speeds

For pulsed ultrasound, which of the following factors determines the frequency of the sound wave? a. PRF b. Transmitter frequency c. Area of the transducer elements d. Pressure applied to the transducer e. All of the above

b. transmitter frequency

If the SPL equals .6mm and the space between the reflectors equals .3mm then will there be one reflector or two? a. one b. two

b. two The axial resolution = .3mm

If the SPL equals .8mm and the space between the reflectors is .5mm with there be one reflector or two? a. one b. two

b. two axial resolution = .4

A transducer with a SPL of 4 mm encounters two reflectors that are 3mm apart. What will appear on the display? a. one b.two

b. two axial resolution = 2mm

The rate of sound attenuation is lowest in: a. Air b. Water c. Liver d. Bone e. Lung

b. water

If the transducer is shocked 1000 times per second, the PRF is __________ a. 10 Hz b. 100 Hz c. 1,000 Hz d. 10,000 Hz

c. 1,000 Hz

Which probe would provide the best axial resolution to measure the thickness of a small structure? a. 5 MHz linear array b. 7 MHz linear array c. 10 MHz linear array d. 5 MHz curved array e. 5 MHz phased array

c. 10 MHz linear array

If we quadruple the amplitude, how many times does the power increase? a. 4 b. 12 c. 16 d. does not change

c. 16

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

Which phenomenon is associated with a pattern by a sound beam after passing through a small aperture? a. Scattering b. Absorption c. Diffraction d. Interference e. Diffuse reflection

c. Diffraction

When the wavelength increases what happens to the propagation speed? a. Increases b. Decreases c. Does not change

c. Does not change

You are building a transducer and took away some of the dampening material. The frequency of the transducer... a. Increases b. Decreases c. Does not change

c. Does not change

A nosocomial infection is defined as one that: a. Is resistant to antibiotics b. Is restricted to the respiratory system c. Is hospital-aquired d. Is not contagious e. Requires patient isolation

c. Is hospital-aquired

Which of the following tissues has the highest propagation speed? a. Water b. Fat c. Kidney d. Air

c. Kidney Kidney is like liver

When scanning with pulse-wave doppler, you would affect the acoustic exposure by changing which of the following? a. doppler gain b. high pass filter c. PRF d. baseline positon e. doppler angle

c. PRF

Axial resolution is determined chiefly by: a. Beam diameter b. Transducer diameter c. Pulse duration d. Attenuation coefficient e. Intensity

c. Pulse duration

What sound-tissue interaction is necessary to form an ultrasound image? a. Rarefaction b. Refraction c. Reflection d. Diffraction e. Interference

c. Reflection

As a general observation about media in diagnostic sonography, sound propagates faster in materials with greater: a. Compressibility b. Acoustic impedance c. Stiffness d.Refractive Index e. All of the above

c. Stiffness

Lateral resolution may be improved by decreasing the... a. SPL b. operating frequency c. beam diameter d. band width

c. beam diameter

Relative measurement of intensity based on a logarithmic scale is expressed in: a. newtons per centimeter squared b. watts per centimeter squared c. decibels d. pascals e. neper

c. decibels

You are building a transducer and you have added more dampening. The frequency of the transducer... a. Increases b. Decreases c. Does not change

c. does not change

Axial resolution can be improves by increasing the... a. wavelength b. focal depth c. frequency d. PRF

c. frequency will shorten the wavelength therefore shortening the SPL

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

When you change the transmit frequency, which of the following is altered? a. displacement amplitude of the particles in the medium b. speed at which the sound wave propagates through the sound wave propagates through the medium c. number of cycles per second d. pulses transmitted per second e. number of electric impulses applied to the transducer per second

c. number of cycles per second

When you adjust the PRF, 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

If the number of cycles in a pulse is increased by 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

If the pressure of amplitude is increases by a factor of 2, then the intensity is increased by a factor of: a. 1 b. 2 c. 3 d. 4 e. 6

d. 4

What is the velocity of an ultrasound wave in bone? a. 333 m/s b. 8050 m/s c. 1540 m/s d. 4080 m/s e.1240 m/s

d. 4080 m/s

If the gain was 50db and the output power is reduced by one-half; the new gain is ______ dB a. 37 b. 25 c. 100 d. 47

d. 47

Doppler pulses used for diagnostic purposes are typically how many cycles long? a. 0-2 b. 2-3 c. 4-5 d. 5-30 e. greater than 100

d. 5-30

During production of a sonogram, you image the following structures. Which is the MOST attenuating? a. Blood b. Bile c. Soft Tissue d. Calicification e. Muscle

d. Calicification

Which of the following would most likely have the highest SPTA value? a. CW doppler b. B-mode real-time scanners c. static B-mode scanners d. PW doppler e. Fetal monitor doppler

d. PW doppler

Another term for nonspecular reflection is: a. Destructive interference b. Refraction c. Diffraction d. Scattering e. Absorption

d. Scattering

Which of the following factors does NOT affect impedance? a. Stiffness b. Density c. Muscle d. bone e. liver

d. bone

Wavelength depends on what two factors? a. frequency and amplitude b. amplituide and propagation speed c. period and frequency d. frequency and propagation speed e. amplitude and intensity

d. frequency and propagation speed

Which of the following parameters would increase acoustic exposure? a. Increase receiver gain b. Increase TGC c. Increase frequency d. Increase transmit power e. Increase fame averaging (persistence)

d. increase transmit power

Which phenomenon is associated with a pattern produced by a sound beam after passing through a small aperature? a. scattering b. absorption c. diffraction d. interference e. diffuse reflection

d. interference

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

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 motion occurring perpendicular to the direction of propagation

d. particle motion occurring in the same direction as propagation

What occurs when you image a structure with an oblique incidence? a. a very strong reflection will occur since this is the optimal angle 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 the poor scanning angle d. the angle of reflection will be orientated away from the transducer, resulting in decreased visualization of the structure e. the amount of scattering will be reduced with a scanning angle of 45 degrees, resulting in a cleaner image with reduced artifactual echoes

d. the angle of reflection will be orientated away from the transducer, resulting in decreased visualization of the structure

What does the mechanical index indicate on an ultrasound system? a. the maximum temperature increase in tissue b. the minimum temperature increase in tissue c. acoustic power in milliwatts d. the likelihood of cavitation during an ultrasound exam e. minutes of exposure time before tissue heating is too great

d. the likelihood of cavitation during an ultrasound exam

The best axial resolution can be expected from a pulse-echo instrument with which of the following characteristics.. a. 1.0 MHz, 2 cycles/pulse b. 2.5 MHZ, 4 cycles/pulse c. 2.5 MHz, 4 cycles/pulse d. 4 MHz, 4 cycles/pulse e. 4 MHz, 2 cycles/pulse

e. 4 MHz, 2 cycles/pulse Axial resolution is best with high frequency and low SPL (cycles/pulse)

What should you do to avoid nosocomial and cross infection with sonographic probes? a. Probe cleaning should always precede high-level disinfection b. Covering a probe with a condom is a sufficient barrier to infection for intracavitary probes c. Disinfection using a germicide compatible with the transducer is indicated when the probe is in contact with mucous membranes d. Alcohol soak of each probe should occur between patients e. A and C

e. A and C

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

Which intensity parameter is not applicable for continuous-wave ultrasound? a. SATA b. SPTA c. SPPA d. SAPA e. C and D

e. C and D

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

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. Wavelenth e. None of the above

e. None of the above

Which of the following would show the highest intensity value? a. SATP b. SATA c. Im d. SPPA e. SPTP

e. SPTP

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

Bulk modulus is closely related to which of the following qualities? a. attenuation b. frequency c. wavelength d. volume e. stiffness

e. Stiffness

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

Using a hydrophone, you can measure: a. impedance b. pressure amplitude c. duty factor d. all of the above e. b and c only

e. b and c only

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 halving the scattering intensity d. doubling the frequency results in quartering the scattering e. scattering intensity is proportional to frequency raised to the fourth power

e. scattering intensity is proportional to frequency raised to the fourth power

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 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

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

e. the percentage of diffraction distal to the interface