Final
These transducer systems typically produce an image that, throughout its entire depth, is approximately as wide as the ultrasound transducer itself.
Linear switched (also called linear sequential) array transducer
With these transducers, a trapezoidal image shape is produced. The image is flat at the top and becomes progressively wider at increasing depths.
Vector array transducer
The impedance of a transducer's matching layer is 2.6 MRayls and the impedance of the piezoelectric crystal is 3.4 MRayls. If this is assumed to be a good imaging system, what is the best estimate for the impedance of the skin? A. 1.5 MRayls B. 3.8 MRayls C. 3.4 MRayls D. 2.8 MRayls
a) 1.5 MRayls
Which imaging technique usually displays a single hagged line of varying heights? a) a-mode b) b-mode c) c-mode d) I-mode
a) a-mode
The information that is processed by a standard duplex ultrasound system includes all of the following except: a) attenuation b) amplitude c) frequency d) time of arrival
a) attenuation
A sound wave reaches a rough or irregular border between two media. Under these explicit circumstances, which process is most likely to occur? a) backscatter reflection b) specular reflection c) rayleigh scattering d) refraction
a) backscattering reflection
What is the smallest mount of digital storage called? a) bit b) byte c) pixel d) fractal
a) bit
Which of the following terms best describes the mechanistic investigation of bioeffects? a) cause and effect b) exposure-response c) cause-response d) exposure-cure
a) cause and effect
Which of the following are acceptable unites for the amplitude of an acoustic wave? (more than one answer may be correct) a) cm b) Pascals c) Gauss d) Watts
a) cm and b) Pascals
Which of the following reports the relative strength of an ultrasound wave? a) decibles b) watts c) w/cm2 d) pascals
a) decibles
Which of the following components typically has the lowest dynamic range? a) display b) pulsar c) amplifier d) demodulator
a) display
What is the use of a greater number of channels to receive echoes from ever increasing depths called? A. dynamic aperture B. apodization C. dynamic frequency tuning D. subdicing
a) dynamic aperture
What is the primary reason blood moves from one location to another? a) energy gradient b) anemia c) pressure gradient d) systole e) friction
a) energy gradient
How does slice thickness artifact commonly express itself? A. fill in of cystic structures B. improper brightness of reflectors C. absence of reflectors D. strong linear echoes
a) fill in cystic structures
The attenuation of an acoustic wave traveling through bone is ____ its attenuation through soft tissue. A. greater than B. less than C. equal to
a) greater than
A particle within a transverse wave is traveling vertically. What is the direction of the wave's propagation? a) horizontal b) vertical c) diagonal; both horizontal and vertical d) cannot be determined
a) horiztonal
Which of the following explains the difference in sound beam shape created by a disc-shaped crystal from that of a small chip of PZT? a) Huygen's principle b) Snell's law c) bernoulli's law d) murphy's law
a) hugyen's principle
What is the advantage of using a 1 and 1/2 dimensional array transducer? a) improved elevational transducer b) improved lateral resolution c) improved axial resolution d) improved temporal resolution
a) improved elevational resolution
What happens to venous flow in the legs when an individual exhales? a) increases b) decreases c) remains the same
a) increases
What happens to venous return to the heart when an individual inhales? a) increases b) decreases c) remains the same
a) increases
How is weight related to a sonographer's time spent exercising? a) inversely b) conversely c) directly d) unrelated
a) inversely
What happens to the diaphragm when an individual breathes out? a) it ascends into the thorax b) it descends into the abdomen
a) it ascends into the thorax
What happens to an acoustic beam's intensity when the power in the beam increases by 25% while the cross-sectional area of the beam remains the same? a) it increases by 25% b) it increases by 75% c) it increases by 50% d) it decreases by 25%
a) it increases by 25%
An acoustic wave is traveling from medium X to medium Z. Medium X has a propagation speed of 1,457 m/sec and an impedance of 1.44 MRayls. Medium Z's propagation speed is 1,644 m/s and its impedance is 1.26 MRayls. The angle of incidence is 32 degrees. What is true of the angle of the transmitted wave? A. it is greater than 32 degrees B. it is equal to 32 degrees C. it is less than 32 degrees D. cannot be determined
a) it is greater than 32 degrees
What is true of acoustic speckle? A. its effects are mild and it tends to slightly degrade images B. it is a rare artifact that does not occur in real-time imaging C. its effects are dramatic D. it is eliminated with apolarization
a) its effects are mild and it tends to slightly degrade images
Which of the following techniques is external focusing? a) lens b) curved crystal c) electronic
a) lens
With these transducers, the ultrasound beam is focused with an acoustic lens, a mirror, or by milling the piezoelectric crystal in a curved shape (more than one answer may be correct) a) linear switched array transducer b) linear phased array transducer c) mechanical transducer d) annular array transducer e) convex or curvilinear array transducer
a) linear switched array transducer c) mechanical transducer and e) convex or curvilinear transducer
Which of the following units are appropriate to describe the period of an acoustic wave? (more than one answer may be correct) a) minutes b) microseconds c) meters d) mm/us e) cubic centimeters
a) minutes and b) microseconds
What are the units of the intensity reflection coefficient? a) none b) w/cm2 c) watts d) dB
a) none
Which of the following determines the gray scale in a Doppler spectrum? a) number of reflections b) velocity c) frequency shift d) laminar flow
a) number of reflections
Some ultrasonic bioeffects studies are performed in vivo. What is the meaning of the term in vivo? A. observable in a living body B. observations based on an experiment C. discernible in a test tube D. estimated in a computer simulation
a) observable on a living body
Axial resolution describes the accuracy related to visualizing two structures that are ____________ to a sound beam's main axis a) parallel b) perpendicular c) oblique d) normal
a) parallel
What is the decibel representation when an acoustic signal is amplified? a) positive b) negative c) equal to zero
a) positive
A sonographer adjusts the maximum imaging depth of an ultrasound system. Which of the following also changes? (more than one answer may be correct) a) pulse repetition period b) wavelength c) pulse repetition frequency d) frequency
a) pulse repetition period and c) pulse repetition frequency
Which one of the following does not belong in the group below? a) receiver gain b) energy output c) pulser power d) acoustic power e) transmitter output f) output gain
a) receiver gain
What is a comet tail artifact's fundamental mechanism of formation? A. reflection B. rarefaction C. refraction D. attenuation
a) reflection
An ultrasound wave approaches an interface between two media at a 90 degree angle. The propagation speeds of the media are identical. However, the densities of the medium are different. Which is true? a) reflection will definitely occur b) reflection will definitely not occur c) refraction may occur d) none of the above
a) reflection will definitely occur
Six distinct, equally spaced reflections appear on an image at ever increasing depths. What type of artifact is this? a) reverberation b) ring down c) mirror imaging d) longitudinal resolution
a) reverberation
Grating lobes are produced by the same mechanism as which other artifact? A. side lobes B. reverberation C. transaxial lobes D. acoustic speckle
a) side lobes
The process of demodulation incorporates which of the following tasks? (more than one answer may be correct) a) smoothing b) amplification c) rectification d) decompression
a) smoothing and c) rectification
What happens to digital image when the pixel density increases? a) spatial detail improves b) temporal resolution c) the field of view expands d) there are more shades of grey
a) spatial detail improves
Two small cysts, positioned perpendicular to the main axis of a sound beam, are 2.4 mm apart. What determines whether they appear as two distinct images on the system's display? A. the beam width B. the pulse length C. the PRF D. the TGC
a) the beam width
What determines the initial intensity of an ultrasound beam? a) the source of the sound wave b) the medium through which the sound travels c) both A and B d) Neither A or B
a) the source of the sound wave
Which of the following is best described as an analog number? a) the weight of a person b) the number of people in a room c) the number of stars in the sky d) the number of tires on a car
a) the weight of a person
All of the following may be used to evaluate Doppler systems except: a) tissue equivalent phantom b) moving belt phantom c) vibrating string phantom d) doppler phantom
a) tissue equivalent phantom
A PZT crystal in the shape of a disc produces a continuous ultrasound wave. The beam is unfocused True or False? If the diameter of the acoustic beam produced by a crystal is 8 mm at a depth of twice the near zone length, then the PZT crystal has a diameter of 8 mm. a) true b) false
a) true
A PZT crystal in the shape of a disc produces a continuous ultrasound wave. The beam is unfocused. True or False? The greater the diameter of a transducer's piezoelectric crystal, the longer the near zone length is a) true b) false
a) true
A PZT crystal in the shape of a disc produces a continuous ultrasound wave. The beam is unfocused. True or False? The far zone is the only region where the beam diameter exceeds the transducer diameter? a) true b) false
a) true
An ultrasound pulse propagates from soft tissue through a mass. The sound's propagation speed in the mass is 1,575 m/s. True or False? The wavelength increases while the wave travels through the mass? a) true b) false
a) true
True or False? A sonographer can routinely chance the power of a wave emitted by a transducer used in diagnostic ultrasonic imaging? a) true b) false
a) true
True or False? Attenuation and propagation speed are unrelated a) true b) false
a) true
True or False? Both linear and phased array technologies have the ability to variably focus an ultrasound beam to different depths a) true b) false
a) true
True or False? Color flow Doppler exams tend to have lower temporal resolution than traditional two-dimensional, real-time imaging a) true b) false
a) true
True or False? Focused sound beams are considered less likely to create bioeffects because the beams will strike fewer gas bubbles that could potentially cavitate a) true b) false
a) true
True or False? For digital image information to be displayed on a conventional television screen, the data must be processed by a digital-to-analog converter a) true b) false
a) true
True or False? In a pulsed Doppler exam, the use of a higher transducer frequency increases the likelihood that aliasing will appear. a) true b) false
a) true
True or False? In general, ultrasound imaging transducers have a lower quality factor and a wider bandwidth than therapeutic ultrasound transducers a) true b) false
a) true
True or False? Proper quality assurance programs require the assessment of every transducer used in the clinical laboratory a) true b) false
a) true
True or False? Side lobe, grating lobe, and refraction artifacts all reduce lateral resolution? a) true b) false
a) true
True or False? Soft tissue is an imaginary construct that actually does not exist? a) true b) false
a) true
True or False? The "curved pattern" of delays in the electrical spikes used in a linear phase array transducer focuses the beam during transmission a) true b) false
a) true
True or False? The mechanistic approach to the study of bioeffects and safety includes the identification of a theoretical construct that could produce an effect a) true b) false
a) true
True or False? The period of an ultrasound wave is related to the frequency and the same, regardless of whether the wave is pulsed on continuous? a) true b) false
a) true
True or False? The primary purpose of demodulation is the preparation of the electrical signal for display on a television monitor a) true b) false
a) true
True or False? The pulse duration does not profoundly influence the lateral resolution? a) true b) false
a) true
True or False? The pulse duration of an ultrasound and transducer system does not change significantly as long as the system components remain unchanged? a) true b) false
a) true
True or False? The purpose of the backing material of an ultrasound transducer is to shorten the pulses, therby creating images with better image quality? a) true b) false
a) true
True or False? The shorter the pulse length, the better the picture? a) true b) false
a) true
True or False? The signal to noise ratio remains unchanged when a sonographer adjusts receiver gain a) true b) false
a) true
True or False? Velocity mode color Doppler and variance mode color Doppler will produce identical images when blood flow patterns are laminar a) true b) false
a) true
True or False? Waves in the ultrasound range behave in the same general manner as sound waves that are audible? a) true b) false
a) true
True or False? When using an instrument typical of today's diagnostic imaging devices, a higher frequency transducer is likely to improve the axial resolution a) true b) false
a) true
True or False? When using standard ultrasonic imaging instrumentation, the lateral resolution has a higher numerical value than the axial resolution? a) true b) false
a) true
True or False? While imaging soft tissue, the spatial pulse length does not change as long as the components of the ultrasound system are the same? a) true b) false
a) true
True or False? With standard diagnostic imaging instrumentation, the sonographer has the ability to vary the amplitude of a sound wave produced by the transducer? a) true b) false
a) true
True or False? annular phased array transducers focus sound beams in all planes and at all depths? a) true b) false
a) true
True or False? with a specific ultrasound system and transducer, the system's axial resolution is invariant, and the sonographer can do nothing to change it? a) true b) false
a) true
Two ultrasound systems, one producing sound with a frequency of 3 MHz and the other at 6 MHz, are used to image a patient. The maximum imaging depth of both exams is 8cm. True or False? The period of the 3 MHz sound is greater than the period of the 6 MHz sound a) true b) false
a) true
Two ultrasound systems, one producing sound with a frequency of 3 MHz and the other at 6 MHz, are used to image a patient. The maximum imaging depth of both exams is 8cm. True or False? The pulses produced by both systems travel at the same speed in the patient. a) true b) false
a) true
Two waves, a 5 MHz ultrasonic wave and a 5 kHz audible wave, travel through soft tissue. True or False? The period of the 5 MHz wave is less than the period of the audible wave? a) true b) false
a) true
With regard to mechanical transducers, is this statement true or false? The ultrasound beam is directed in many different directions to create an imaging plane a) true b) false
a) true
With regard to mechanical transducers, is this statement true or false? There is communication between the pulser of the ultrasound system and the piezoelectric crystal of the transducer a) true b) false
a) true
With regard to the backing material of a pulsed ultrasound transducer, is the following true or false? The spatial pulse length is decreases. with the application of backing material a) true b) false
a) true
With regards to CW Doppler, is this statement True or False? The duty cycle of the continuous wave is 100% a) true b) false
a) true
A system has three transducers with frequencies of 7.5 MHz, 5 MHz and 3.25 MHz. Aliasing appears while using the 5.0 MHz transducer during a pulsed Doppler exam. What should the sonographer do? A. use the 3.25 MHz transducer B. use the 7.5 MHz transducer C. nothing; the other transducers do not provide solutions to the problem
a) use the 3.25 MHz
Which artifact is created by sound moving through a medium with a propagation speed less than soft tissue? A. vertical misregistration B. horizontal misregistration C. lateral resolution D. ring down
a) vertical misregistration
What are the units of the transmitted intensity of a sound wave? a) w/cm2 b) watts c) dB d) none it is unitless
a) w/cm2
The lateral resolution of an ultrasound system is primarily determined by the ______. a) width of the sound pulse b) length of the ultrasound pulse c) duration of the sound pulse d) none of the above
a) width of the sound pulse
Propagation speed can be correctly recorded with which of the following units? (more than one answer may be correct) a) miles per hour b) mm/msec c) km/sec d) inches per year
all answers are correct
What are the units of pressure measurement of an acoustic wave? (more than one answer may be correct) a) atmospheres (atm) b) pascals (Pa) c) millimeters of mercury (mm Hg) d) Pounds/sq. inch (lb/in2)
all of the answers are correct
The arterial blood pressure of a supine individual is 120 mmHg. What is the hydrostatic pressure at the subject's hips? a) 100 mmHg b) 0 mmHg c) 40 mmHg d) 120 mmHg e) -120 mmHg
b) 0 mmHg
What is the wavelength of 10MHz sound in soft tissue? a) 0.77 mm b) 0.15 mm c) 1.54 mm d) 10 mm
b) 0.15 mm
An ultrasonic pulse has a pulse repetition period of 1.2 msec, a spatial pulse length of 2.0 mm, and a wavelength of 0.4 mm. What is the axial resolution of the system? A. 2.0 mm B. 1.0 mm C. 0.4 mm D. 1.8 mm
b) 1.0 mm
The diameter of a disc-shaped, unfocused piezoelectric crystal is 1.2 cm. The near zone length is 8 cm. What is the best estimate for the lateral resolution at a depth of 16 cm. A. 0.6 cm B. 1.2 cm C. 8 cm D. 16 cm
b) 1.2 cm
Two sound pulses travel through the same medium. One waves frequency is 2 MHz and the other is 10 MHz. Which sound wave has a longer period? A. 10 MHz pulse B. 2 MHz pulse C. neither pulse D. cannot be determined
b) 2 MHz pulse
How many decibels represent a 100-fold increase in the intensity of an acoustic pulse? A. 10 B. 20 C. 100 D. 6
b) 20
What is the approximate number of frames that must be presented each second for the human eye to perceive the display without flickering? a) 2 b) 30 c) 100 d) 500
b) 30
What is the reciprocal of 1/5? a) one-hundredth b) 5 c) 1/5 d) one-millionth
b) 5
How many nanoseconds are in 7 seconds? A. 7,000,000 B. 7,000,000,000 C. 7 million D. 0.00000007
b) 7,000,000,000
When I sonographer increase is the maximum imaging death during an exam, what happens to the PRF? A) PRF increases B) PRF decreases C) PRF remains the same
b) PRF decreases
Which of the following is true of all waves? a) they travel through a medium b) all carry energy from one site to another c) their amplitudes do not change d) they travel in a straight line
b) all carry energy from one site to another
A longitudinal wave propagates from east to west at a speed of 2 miles per hour. What is the direction of motion of the particles within the wave? a) from east to west only b) alternately from east to west and then from west to east c) from north to south only d) alternately from south to north and then from north the south
b) alternately from east to west and then from west to east
Where is a mirror image artifact located? A. sometimes shallower on the image than in the body B. always deeper on the image than in the body C. sometimes the same depth on the image as in the body D. never deeper on the image than in the body
b) always deeper on the image than in the body
What is the amount of attenuation per centimeter that a sound wave undergoes called? a) beam uniformity coefficient b) attenuation coefficient c) attenuation d) duty factor
b) attenuation coefficient
Which choice will result in increased frame rate and temporal resolution? A. decreased propagation speed B. decreased sector size C. decreased lateral resolution D. decreased PRF
b) decreased sector size
What is the primary disadvantage of multiple focal zones along each scan line of a two-dimensional image? a) improved temporal resolution b) decreased temporal resolution c) improved lateral resolution d) improved longitudinal resolution
b) decreased temporal resolution
What happens to the pulse repetition period if the sonographer decreases the maximum imaging depth achieved in an ultrasound scan? a) increases b) decreases c) remains the same d) cannot be determined
b) decreases
While using a particular imaging system, what happens to the duty factor when the depth of view increases? a) increases b) decreases c) unchanged
b) decreases
Which two attributes help establish the acoustic impedance of a medium? a) density and temperature b) density and stiffness c) stiffness and elstance d) elasticity and compressibility
b) density and stiffness
The axial resolution of an imaging system is reported to be 0.85 mm at the beam's focus. What is the closest estimate of the system's radial resolution at a location that is 5 cm deeper than the focus? a) less than 0.85mm b) equal to 0.85mm c) greater than 0.85mm
b) equal to 0.85mm
Which of the following actions would cause a PZT crystal to lose its special properties? a) breaking it in pieces b) exposing it to high temperatures c) exposing it to electrical current d) exposing it to low temperatures
b) exposing it to high temperatures
A PZT crystal in the shape of a disc produces a continuous ultrasound wave. The beam is unfocused. If the narrowest diameter of a sound beam is at a depth of 8cm, then the PZT's crystal's diameter is 16 cm. a) true b) false
b) false
An ultrasound pulse propagates from soft tissue through a mass. The sound's propagation speed in the mass is 1,575 m/s. True or False? The frequency of the wave increases as it travels through the mass? a) true b) false
b) false
Is this statement regarding pulse duration true or false? A sonographer can adjust the duration of an acoustic pulse since it depends on the maximum imaging depth? a) true b) false
b) false
Is this statement regarding pulse duration true or false? The pulse duration cannot be changed under any circumstances or by an action of the sonographer? a) true b) false
b) false
Three sound waves with identical frequencies of 3 MHz have powers of 2 mW, 5mW, and 15 mW. They all travel through three media- wood, brick, and fat - with identical thickness of 5m. True or False? The sound waves travel through all three media at different speeds because the waves have different powers? a) true b) false
b) false
True of False? A bioeffect identified through the mechanistic approach rather than the empirical approach is more likely to have clinical significance a) true b) false
b) false
True of False? The greater the number of bits assigned to each pixel of a digital image, the greater the spatial resolution of the image is a) true b) false
b) false
True or False? All artifacts are errors in imaging that do not represent the true anatomy of the imaged organ. Therefore, they are all undesirable and should be eliminated if possible a) true b) false
b) false
True or False? An ultrasound system with a longer pulse duration will generally have better temporal resolution a) true b) false
b) false
True or False? Color flow Doppler relies on pulsed Doppler principles and it immune to aliasing artifact? a) true b) false
b) false
True or False? Digital scan converters do not use computer technology to process electronic data into images a) true b) false
b) false
True or False? On a color Doppler image, red always represents flow towards the transducer, whereas blue indicates flow away from the transducer a) true b) false
b) false
True or False? Preprocessing of image data occurs after the data has been stored in the scan converter a) true b) false
b) false
True or False? Quality assurance evaluations of ultrasound systems should be performed weekly? a) true b) false
b) false
True or False? The lower the frequency of the ultrasound beam, the shallower is the delay of the TGC curve. a) true b) false
b) false
True or False? The pulser of a mechanical transducer is typically more complex than the pulser of a phased array transducer? a) true b) false
b) false
True or False? The wavelength of an acoustic wave is shorter when it is pulsed rather than continuous? a) true b) false
b) false
True or False? With standard ultrasound pulses, the frequency of the ultrasound changes significantly as the wavw propagates through the body? a) true b) false
b) false
True or False? it is generally believed that the effects of ultrasound on biologic media are minimal? a) true b) false
b) false
True or false? The acoustic impedance of the skin is greater than the acoustic impedances of both the matching layer and the piezoelectric element. a) true b) false
b) false
True or false? The duty factor is a characteristic of an ultrasound and transducer system and does not change as long as the system components remain unchanged a) true b) false
b) false
True or false? the lower the numerical value of the longitudinal resolution, the worse the picture? a) true b) false
b) false
True or false? the period of a sound wave determines whether refraction will occur? a) true b) false
b) false
Two waves, a 5 MHz ultrasonic wave and a 5 kHz audible wave, travel through soft tissue. True or False? The ultrasound wave travels much faster than the audible wave? a) true b) false
b) false
With regard to CW Doppler, is this statement True or False? Problems with aliasing significantly limit its clinical ability. a) true b) false
b) false
With regard to the backing material of a pulsed ultrasound transducer, is the following true or false? The damping material helps to decrease the pulse repetition period achieved at a given imaging depth a) true b) false
b) false
With regard to the backing material of a pulsed ultrasound transducer, is the following true or false? The pulse duration is increased as a result of the presence of backing material a) true b) false
b) false
Which of the following causes the greatest amount of inertial energy loss? a) pulsatile flow b) flow through a stenosis c) phasic flow d) steady flow e) parabolic flow
b) flow through a stenosis
What is the point of location where a beam reaches its smallest dimension? a) near zone b) focus c) penetration depth d) focal depth
b) focus
Which of the following is not a potential mechanism for production of bioeffects from ultrasound exposure to the body? a) temperature elevation b) fractionation c) cavitation d) vibration
b) fractionation
What term describes the number of cycles that an acoustic variable competes in a second? a) period b) frequency c) pulse repetition period d) variable rate
b) frequency
The amplitude of an acoustic wave is increased. Which of the following will most likely remain unchanged? (more than one answer may be correct) A. power B. frequency C. period D. intensity
b) frequency and c) period
As sound travels deeply into the far zone, the beam diverges, or spreads out. Which of the following will result in a minimum beam divergence deep in the far zone? a) small diameter, high frequency b) high frequency, large diameter c) large diameter, low frequency d) low frequency, small diameter
b) high frequency, large diameter
Which of the following terms does not belong with the others? a) increased depth of view b) increased duty factor c) increased pulse repetition period d) decreases puled repetition frequency
b) increased duty factor
What happens to the intensity of an ultrasound beam when the beam's cross-sectional area remains unchanged while the amplitude of the wave triples? a) it triples b) it increases nine-fold c) it remains the same d) none of the above
b) it increases nine-fold
An acoustic wave is traveling from medium X to medium Z. Medium X has a propagation speed of 1,457 m/sec and an impedance of 1.44 MRayls. Medium Z's propagation speed is 1,644 m/s and its impedance is 1.26 MRayls. The angle of incidence is 32 degrees. What is true of the angle of reflection? A. it is greater than 32 degrees B. it is equal to 32 degrees C. it is less than 32 degrees D. cannot be determined
b) it is equal to 32 degrees
An acoustic wave is in medium A and traveling toward medium B. The sound beam's angle of transmission into Medium B with relation to the boundary is 79 degrees. Sound's propagation speed is 1,547 m/sec in medium A and 1,745 m/sec in medium B. if reflection and transmission both occur at the boundary, what can be said of the reflection angle? a) it is greater than 79 degrees b) it is less than 79 degrees c) it is equal to 79 degrees d) cannot be determined
b) it is less than 79 degrees
What is the importance of describing sound beam intensities in a variety of ways with regard to space and time? a) it allows better transducer design b) it's important when studying bioeffects c) it optimizes image quality d) harmonics can be measured
b) it's important when studying bioeffects
Sound traveling through blood attenuates to a ____ extent than when traveling through soft tissue. A. greater B. lesser C. relatively equal
b) lesser
If sound travels at exactly 1,540 m/sec in a particular medium, then the medium ____. A. must be soft tissue B. may be soft tissue C. cannot be soft tissue
b) may be soft tissue
All of the following describe dynamic receive focusing except: a) delay pattern changes continuously throughout reception b) may be used by single crystal transducers c) focusing occurs at many depths d) automatically performed by system
b) may be used by single crystal transducers
Which two of the following terms are associated with phased array transducers? a) lens b) multi-focus c) mirror d) adjustable e) external
b) multi-focus and d) adjustable
With pulsed wave ultrasonic imaging, what helps to establish the primary frequency of the acoustic energy discharged by the transducer? A. piezoelectric crystal diameter B. piezoelectric crystal thickness C. damping material density D. ultrasound system electronics
b) piezoelectric crystal thickness
Which of the following epidemiological studies is considered most likely to produce meaningful results? a) retrospective and prospective b) prospective and randomized c) retrospective and empirical d) prospective and mechanistic
b) prospective and randomized
Which best describes the elements in a linear phased array transducer? a) rectangular, 1/4 wavelength thick b) rectangular, 1/2 to 1/4 wavelength wide c) circular d) squares, 1/2 wavelength thick
b) rectangular, 1/2 to 1/4 wavelength wide
Side lobe artifact usually results in all of the following except: A. hollow structures appearing "filled in" on the image B. reflectors not appearing on an image C. reflectors appearing in improper locations on the image D. reflectors appearing in multiple locations on the image
b) reflectors not appearing on an image
Compared to soft tissue, the speed of an acoustic wave through lung tissue is ___________. a) faster b) slower c) equal d) cannot be determined
b) slower
Which of the following statements regarding cavitation is true? a) it is never been observed in any biologic media b) stable cavitation relates to oscillating bubbles while transient relates to bursting bubbles c) it is nonlethal bioeffect produced in animal experiments d) waves with peak pressures less than 100 MPa can never induce cavitation
b) stable cavitation relates to oscillating bubbles while transient relates to bursting bubbles
Which technique of liner array transducer design has virtually eliminated the appearance of grating lobe artifact on modern ultrasound systems? a) demodulation b) sub-dicing c) deconvolution d) none of the above
b) subdicing
The process of elimination low amplitude signals from further processing is called all of the following except: a) reject b) subordination c) threshold d) suppression
b) subordination
Two digital scan converters are undergoing evaluation. System A has 1,000,000 pixels and the picture size is 100 square inches. System B has an image size of 10 square inches composed of 250,000 pixels. Which image is more likely to display very small details? A. System A B System B C. both are the same D. cannot be determined
b) system B
Two transducers send ultrasound pulses into soft tissue. One transducer emits sound with a 4 MHz frequency, and the other produces sound at a 6 MHz frequency. Each pulse contains 4 cycles. Which has a greater spatial pulse length? a) the 6 MHz transducer b) the 4 MHz transducer c) they are the same d) cannot be determined
b) the 4 MHz transducer
In which region of a sound beam is focusing most effective? a) the very shallow near zone b) the end of the near zone c) very deep in the far zone d) throughout its entire length
b) the end of the near zone
What does the far gain of a depth gain compensation curve represent? A. median amplification related to compensation B. maximum amplification related to compensation C. minimum amplification related to compensation D. maximum attenuation related to compensation
b) the maximum amplification related to compensation
Two ultrasound systems are identical except for the diameter of the transducer's piezoelectric crystal. Which system has the deepest focus? a) the system with the smaller diameter crystal b) the one with the larger diameter crystal c) their foci would be the same depth
b) the one with the larger diameter crystal
What is epidemiology the study of? a) large groups b) the prevalence of disease c) acoustic bioeffects on the fetus d) in vitro effects
b) the prevalence of disease
All of the following are true of write zoom except: a) preprocessing function of the receiver b) the same number of pixels are in the original ROI and the zoomed image c) the pixel size in the zoomed image and the ROI are the same d) in comparison to the zoomed image, fewer ultrasound pulses are used to create the original ROI
b) the same number of pixels are in the original ROI and the zoomed image
All of the following are true about sound waves except? a) they are mechanical b) they are transverse c) they carry energy from place to place d) they generally travel in a straight line
b) they are transverse
Which component of an ultrasound system is made of lead zirconate titanate (PZT)? a) transducer's matching layer b) transducer's active element c) transducer's damping material d) scan converter's computer chips
b) transducer's active element
The two most common color maps used in color flow imaging are: a) variance and direct b) variance and velocity c) turbulence and variance d) power and velocity
b) variance and velocity
The propagation speeds of ultrasound waves in muscle, liver, kidney, and blood are _______ a) exactly the same b) very similar to each other c) vastly different
b) very similar to each other
What is the range of Doppler shifts commonly measured in clinical exams? a) -10kHz to 1 MHz b) -0.5 MHz to 0.5 MHz c) -0.02 MHz to 0.02 MHz d) none of the above
c) -0.02 MHz to 0.02 MHz
What is the maximum permissible value for both the intensity reflection coefficient and the intensity transmission coefficient? a) 100 b) 1% c) 1 d) infinity
c) 1
Two otherwise identical Doppler studies are performed, except that the angle between flow and the sound beam is 0 degrees in the first study and 60 degrees in the second. The velocity measured in the first study is 2 m/s. What velocity will be measured in the second study? A. 2 m/s B. 4 m/s C. 1 m/s D. cannot be determined
c) 1 m/s
When using a 4 MHz transducer, a Doppler shift of 3,000 Hz is recorded. What will the Doppler shift be when a 2 MHz transduce is used? a) 3,000 Hz b) 2 Hz c) 1,500 Hz d) 6,000 Hz
c) 1,500 Hz
A maximum Doppler shift is obtained when the angle between the direction when the angle between the direction of blood flow and the direction of the sound beam is a) 10 degrees b) 90 degrees c) 180 degrees d) 270 degrees
c) 180 degrees
An ultrasound system with a 4.0 MHz transducer is used to image structures as deep as 15 cm. Twenty images are produced each second, requiring 100 acoustic pulses. What is the PRF of the system? a) 1,500 Hz b) 300 Hz c) 2,000 Hz d) 4 MHz
c) 2,000 Hz
In soft tissue, sound travels to a reflector and back to the transducer in 39 microseconds. How deep is the reflector? a) 2 cm b) 6 cm c) 3 cm d) cannot be determined
c) 3 cm
A sound beam with an intensity of 45 W/cm2 strikes a boundary and 70% of the wave's intensity is reflected. How much is transmitted? a) 45 w/cm2 b) 25 w/cm2 c) 30% d) 100%
c) 30%
Which transducer has the worst axial resolution? a) 2 cycles/pulse, 4 MHz b) 4 cycles/pulse, 4 MHz c) 4 cycles/pulse, 2 MHz d) 2 cycles/pulse, 2 MHz
c) 4 cycles/pulse, 2 MHz
What is the best estimate of the propagations peed of the ferroelectric element of a transducer typical diagnostic imaging laboratory? a) 1.2 mm/usec b) 4.0 m/sec c) 4.0 mm/usec d) 1.0 km/sec
c) 4.0 mm/usec
Which of the following is a typical value for the amplification of a signal by the receiver? a) 50 to 100 wats b) -50 to -100 dB c) 50 to 100 dB d) 5 to 25 w/cm2
c) 50 to 100 dB
With which of the following pulses would lateral resolution be worst? a) 10 MHz, 4 mm beam diameter, 4 cycles per pulse b) 4 MHz, 4 mm beam diameter, 2 cycles per pulse c) 7.5 MHz, 8 mm beam diameter, 2 cycles per pulse d) 6 MHz, 2 mm beam diameter, 2 cycles per pulse
c) 7.5 MHz, 8 mm diameter, 2 cycles per pulse
Compare two sound waves, A and B. The frequency of wave A is one-third that of wave B. How does the period of wave A compare with the period of wave B? A. A is one-third as long as B B. A is the same as wave B C. A is three times as long as B D. cannot be determined
c) A is three times as long as B
What is a decibel? a) the absolute value of a number b) a range of values c) a relationship between two numbers d) none of the above
c) a relationship between two numbers
Spectral analysis of color flow Doppler is most commonly performed by with of the following techniques? a) zero-crossing detectors b) Fast Fourier transformations c) autocorrelation d) chirp-Z transforms
c) autocorrelation
Which imaging modality places dots dissimilar gray scale on the display? a) a-mode b) I-mode c) b-mode d) m-mode
c) b-mode
What term is used to accurately describe the effects of an ultrasound wave on living tissue? a) toxic effects b) acoustic propagation c) biological effects d) transmission properties
c) biological effects
Which display is limited to a single pair of brightness or display levels? A. CRT B. binary C. bistable D. grayscale
c) bistable
Which of the following terms is not associated with a wide dynamic range limit? a) low contrast b) many shades of grey c) bistalbe
c) bistable
In diagnostic imaging, what determines the spatial pulse length? a) the ultrasound system b) the medium through which the pulse travels c) both A and B d) neither A or B
c) both A and B
The wavelength of an ultrasonic wave is determined by: A. the sound source B. the medium through which the wave travels C. both A and B D. neither A nor B
c) both A and B
Two ultrasound systems produce acoustic pulses. A pulse from system 1 has a wavelength of 0.5mm, 4 cycles per pulse, and a pulse repetition period of 1.2 msec. The pulses from system, 2 have a wavelength of 1.0 mm, 2 cycles per pulse, and a pulse repetition period of 1.8 msec. Which ultrasound system will have a lower numerical value of axial resolution? a) system 1 b) system 2 c) both are the same d) cannot be determined
c) both are the same
How can the volume of an irregularly shaped object be measured most accurately? a) by visual inspection b) by its weight c) by immersing it in water d) by ultrasound scanning
c) by immersing it in water
Of the following, which imaging modality has the poorest temporal resolution? a) two-dimensional, real-time b) a-mode c) color flow imaging d) m-mode
c) color flow imaging
Which of the following is not a measure of area? a) square cm b) meters squared c) cubic meters d) feet x feet
c) cubic meters
Where are shadowing artifacts commonly seen on an acoustic scan? A. deeper than a structure with a high impedance B. shallower than a structure with a low propagation speed C. deeper than a structure with a high attenuation D. alongside of a structure with a low elastance
c) deeper than a structure with a high attenuation
Two waves arrive at a same location and interfere. The resultant sound wave is smaller than either of the two original waves. What is it called? a) constructive interference b) angular interaction c) destructive interference d) in-phase wavws
c) destructive interference
What conditions are necessary for refraction to occur at a boundary between two media? a) unequal acoustic impedances and normal incidence at the boundary b) unequal densities of the media and normal incidence at the boundary c) dissimilar propagation speeds and oblique incidence at the boundary d) different elasticities of the media and oblique incidence
c) dissimilar propagation speeds and oblique incidence at the boundary
The relationship between the largest and the smallest signal amplitudes processed by a component of an ultrasound system is called ____ and his units of ________. a) decibels, watts b) intensity, w/cm2 c) dynamic range, dB d) proportionally, dB
c) dynamic range, dB
Which of these techniques is consistent with variable or multi-focusing? a) lens b) curved crystal c) electronic
c) electronic
With standard diagnostic imaging instrumentation, which has the higher numerical value? A. axial resolution B. lateral resolution C. elevational resolution
c) elevational resolution
Unexpectedly low attenuation results in which of the artifacts listed below? A. refraction B. attenuation C. enhancement D. shadowing
c) enhancement
Which of the following is not one of the physical processes that contributes to attenuation of ultrasound waves passing through soft tissue? a) reflection b) redirection of sound in many directions c) focusing d) conversion of acoustic energy to hear
c) focusing
The Doppler effect is observes as a change in ______ and has units of _______. a) amplitude, watts b) power, watts c) frequency, per second d) wavelength, millimeters
c) frequency, per second
To which of the following is Rayleigh scattering related? a) half of the wavelength b) square root of propagation speed c) frequency^4 d) PRF
c) frequency^4
What is the meaning of the term "analysis" in the context of spectral analysis of Doppler signals? a) building a sophisticated signal from components b) building a simplified signals from components c) identifying the building blocks or components of a complex signals d) measuring a complex signal, then modifying its information context
c) identifying the building blocks or components of a complex signal
If the ____ of two media are different and sound strikes a border between the media at 90 degree incidence, then reflection will occur. a) conductances b) densities c) impedances d) propagation speeds
c) impedances
How are the piezoelectric crystals excited when using an ultrasound system with a sequential linear array transducer? A. singly and in order: the first crystal, the second crystal, etc B. in pairs: the first 2 crystals, the 3rd and 4th, etc C. in a specific order D. in a random sequence
c) in a specific order
Which of the following actions will improve the signal to noise ratio? a) increase dynamic range b) increase receiver gain c) increase output power d) increase time gain compensation
c) increase output power
If red blood cells are traveling toward a transducer, the frequency emitted by the transducer is ________ the frequency reflected from the red blood cells. a) greater than b) equal to c) less than
c) less than
Which selection has the highest mechanical index? a) high frequency, high power b) high PRF, high intensity c) low frequency, high pressure d) high spatial pulse length, high PRF
c) low frequency, high pressure
With these transducers, the ultrasound beam is steered by a motor, a rotating reflecting mirror, or a similar device. (more than one answer may be correct) a) linear switched array transducer b) linear phased array transducer c) mechanical transducer d) annular array transducer e) convex or curvilinear array transducer
c) mechanical transducer and d) annular phased array transducer
Acoustic impedance is a property of the ________ and has units of ________. a) source and medium, Imps b) Medium, dB c) Medium, rayls d) Medium, Ohms
c) medium, rayls
Two sound waves with frequencies of 5 and 3 MHz travel to a depth of 8 cm in a medium and then reflect back to the surface of the body. Which acoustic wave arrives first at the surface of the body? A. the 5 MHz wave B. the 3 MHz wave C. neither D. cannot be determined
c) neither
Two ultrasound transducers are used to perform Doppler exams on the same patient. The exams are identical except that the transducer frequencies are 5 and 2.5 MHz. Which exam will measure the highest Doppler shift? A. the 2.5 MHz exam B. the 5 MHz exam C. neither D. cannot be determined
c) neither
Two sound pulses travel through the same medium. One waves frequency is 2 MHz and the other is 10 MHz. Which pulse has a lower propagation speed? a) 10 MHz pulse b) 2 MHz pulse c) neither pulse d) cannot be determined
c) neither pulse
Which term does not belong in the group below? a) orthogonal b) at right angles c) oblique d) 90 degrees e) normal f) perpendicular
c) oblique
Which term has a meaning other than normal incidence? A. orthogonal incidence B. perpendicular incidence C. oblique incidence
c) oblique incidence
Which of the following describes an angle with a measure of 123 degrees? a) orthogonal b) acute c) obtuse d) normal
c) obtuse
The lateral resolution of an ultrasound system is 4 mm. Two structures are separate by 3 mm and lie side by side in relation to the sound beam's main axis. What will most likely appear on the system's display? a) two weak echoes, 4 mm apart b) two bright echoes, 3 mm apart c) one echo d) two bright echoes, 7 mm apart
c) one echo
What is the best estimate of the distance that sound can travel in soft tissue in one second? a) one yard b) one hundred yards c) one mile d) ten miles
c) one mile
What is the smallest part of a digital picture called? a) bit b) byte c) pixel d) fractal
c) pixel
The intensity of an ultrasound beam is defined as the ____ in a beam _____ by the ____ of the beam. A. power, multiplied, diameter B. amplitude, divided, area C. power, divided, area D. amplitude, multiplied, circumference
c) power, divided, area
What type of artifact causes a reflection to be placed at an incorrect depth? A. lateral incertitude B. shadowing C. range ambiguity D. indeterminate relaxation
c) range ambiguity
What is the uniform dispersion of a sound wave in many different directions after striking a very small particle? a) microscattering b) backscattering c) rayleigh scattering d) total absorption
c) rayleigh scattering
Which artifact results in improper side-by-side positioning of reflectors? A. multipath B. comet tail C. refraction D. reverberation
c) refraction
What happens to the pulse duration when a sonographer decreases the maximum imaging depth in an ultrasound scan? a) increases b) decreases c) remains the same d) cannot be determined
c) remains the same
During a pulsed doppler exam, aliasing is observed. All of the following may eliminate aliasing except: A. selection of another imaging view with a shallower sample volume B. selection of another transducer with a lower frequency C. selection of another imaging view that provides a greater PRP D. use of a continuous wave system
c) selection of another imaging view that provides a greater pulse repetition period
For a disc-shaped PZT crystal producing continuous sound, which design will create a beam with the shallowest focus? A. large diameter, low frequency B. large diameter, high frequency C. small diameter, low frequency D. small diameter, high frequency
c) small diameter, low frequency
With standard ultrasonic imaging, what happens to the period of a wave as it propagates? a) increases b) decreases c) stays the same
c) stays the same
Compressibility describes a characteristic of a medium. Which two terms describe the same property as compressibility? a) density and stiffness b) density and conductance c) stiffness and elasticity d) elstance and impedance
c) stiffness and elasticity
Which receiver function creates an image of comparable brightness from top to bottom? A. receiver gain B. output power C. swept-gain compensation
c) swept-gain compensation
The area that starts at the beam's smallest diameter and extends deeper is: A. the distant zone B. the Fresnel zone C. the Fraunhofer zone D. the depth of penetration
c) the Fraunhofer zone
Which component of an ultrasound transducer is made from a slab of epoxy embedded with tungsten particles? a) the matching layer b) the piezoelectric crystal c) the damping material d) the computer chips
c) the damping material
Which of the following determines the spatial resolution of an image on a monitor? a) strength of the electron beam b) form of phosphor coating of the screen c) number of lines of the monitor's display d) the pulse duration
c) the number of lines of the monitor's display
Two ultrasound systems are identical except for the diameter of the transducer's piezoelectric crystal. Which system has the deepest focus? a) the system with the lower PRP b) the system with the higher PRP c) their foci will be at the same depth
c) their foci will be at the same depth
The _________ measures beam intensity at specific locations, whereas a ______ measures the entire energy in a sound beam a) calorimeter, thermocouple b) Schlieren, thermocouple c) thermocouple, calorimeter d) thermocouple, hydrometer
c) thermocouple, calorimeter
If an ultrasound pulse travels through a large mass in the body at a speed of 1.2 mm/us, what happens to the position of all echoes produced from reflectors shallower than the mass? A. they are placed too shallow a location on the image B. they are placed in too deep a location on the image C. they are likely to be placed at the correct depth
c) they are likely to be places at the correct depth
What image is created with a two-dimensional array transducer? A. two-dimensional static image B. two-dimensional real-time image C. three-dimensional real-time image D. B-mode
c) three-dimensional real-time image
A duplex ultrasound system displays ______ information a) m-mode, two dimensional image, a-mode b) a-mode and b-mode c) two-dimensional image and doppler d) two-dimensional image and m-mode
c) two-dimensional image and doppler
A comprehensive and scholarly review of bioeffects is performed by the American Institute of Ultrasound in Medicine for all of the following except: a) ultrasound is a versatile technique b) ultrasound has proven widespread clinical utility c) ultrasound is considered highly toxic d) applications of ultrasound are growing considerably
c) ultrasound is highly toxic
What are the units of pulse duration? a) units of frequency (Hz, etc.) b) msec only c) units of time (sec, years, etc.) d) units of distance (feet, etc.)
c) units of time
What information does the Doppler shift furnish concerning the blood cells that produce it? a) frequency b) speed c) velocity d) density
c) velocity
The power of an ultrasound wave can be reported with which of the following units? (more than one answer may be correct) A. watts/square centimeter B. dB/cm C. watts D. kg/cm2
c) watts
What are the units of intensity? a) Watts b) watts/cm c) watts/cm2 d) dB
c) watts/cm2
What is the vertical axis of a graph called? a) zaxis b) x-axis c) y-axis d) time-axis
c) y-axis
A special sector shape is produced when this transducer is used. It looks like a wedge or a slice of pie, but it doesn't originate at a point. The sector has a blunted, curved shape at the top. The arc at the top of the image may be a few centimeters wide.
convex or curvilinear array transducer
The intensity of a signal declines from 1.5 mW/cm^2 to 0.75 mW/cm^2. How many decibels is this change in intensity? a. 3 dB b. 0.75 dB c. -0.75 dB d. -3 dB
d) -3 dB
The upper limit for the SPTA intensity of a focused ultrasound wave where there have been no observed bioeffects is _________. a) 1 mW/cm2 b) 10 mW/cm2 c) 100 mW/cm2 d) 1 W/cm2
d) 1 W/cm2
What results when the intensity transmission coefficient are added together? a) incident intensity coefficient b) acoustic impedance c) total intensity d) 1.0
d) 1.0
What is the typical voltage of the signal that is the input to the receiver of an ultrasound system? a) 0.1 volts b) 500 mvolts c) 250 volts d) 10 uvolts
d) 10 uvolts
What is the maximum number of shades of gray that are represented with 4 bits? a) 4 b) 8 c) 12 d) 16
d) 16
You are asked to fabricate a pulsed transducer with the highest possible frequency. Which piezoelectric crystal would you select? a) 6 mm thick, 4 cm diameter, 4.0 mm/us propagation speed b) 8 mm thick, 2 cm diameter, 6.0 mm/us propagation speed c) 4 mm thick, 9 cm diameter, 5.0 mm/us propagation speed d) 2 mm thick, 6 cm diameter, 6.0 mm/us propagation speed
d) 2 mm thick, 6 cm diameter, 6.0 mm/us propagation speed
What is the range of frequencies emitted by transducers used in ultrasonic imaging> a) 1 to 3 MHz b) 1 to 1,000 kHz c) -10,000 to +10,000 Hz d) 2,000,000 to 15,000,000 Hz
d) 2,000,000 to 15,000,000 Hz
A sack contains 6 pounds of flour. The content of the bag are increased by a factor of 5. How much flour is in the bag? a) 6 pounds b) 11 pounds c) 60 pounds d) 30 pounds
d) 30 pounds
How many bits are required to display 10 different shades of gray? 14 shades? 15 shades? a) 4 bits, 5 bits, 6 bits b) 10 bits, 14 bits, 15 bits c) 4 bits, 4 bits, 2 bits d) 4 bits, 4 bits, 4 bits
d) 4 bits, 4 bits, 4 bits
According to the AIUM, at what in situ tissue temperature is there danger to a fetus? a) 100 degree C b) 98.7 degrees F c) 1 degree F over normal temperature d) 41 degrees C
d) 41 degrees C
A signal with a 120 dB dynamic range was previously compressed by 40 dB. What is the dynamic range of compressed signal? a) 40 dB b) 120 dB c) 3 dB d) 80 dB
d) 80 dB
Which of the following lists orders the impedance from highest to lowest? a) skin, gel, matching layer, PZT b) PPZT, gel, matching layer, skin c) gel, PZT, matching layer, skin d) PZT, matching layer, gel, skin
d) PZT, matching later, gel, skin
Which imaging modality places time-of-flight information on the x-axis and echo amplitude on the y-axis? a) m-mode b) l-mode c) j-mode d) a-mode
d) a-mode
With pulsed Doppler, what term is used to describe a very high positive Doppler shift that is displayed as a negative waveform? A. attenuation B. filtering C. demodulation D. aliasing
d) aliasing
All of the following are used to describe compensation except: a) swept gain b) depth gan c) time gan d) amplitude gain
d) amplitude gain
How are the piezoelectric crystals of a linear phased array transducer fired? A. in a single specific pattern B. in order, from top to bottom C. at exactly the same time D. at almost exactly the same time
d) at almost exactly the same time
Which of these produces shadowing? a) reverberation b) multi-path c) reflection d) attenuation
d) attenuation
When studying bioeffects which research approach is more important? A. empirical B. mechanistic C. neither is important D. both are equally important
d) both are equally important
Two imaging systems produce acoustic pulses: one pulse is 0.4 usec long and the other is 0.2 usec long. Which is the most likely to provide the best temporal resolution? a) 0.4 usec b) 0.2 usec c) they are the same d) cannot be determined
d) cannot be determined
Two sound pulses travel through the same medium. One waves frequency is 2 MHz and the other is 10 MHz. Which pulse has a longer spatial length? a) 10 MHz pulse b) 2 MHz pulse c) neither pulse d) cannot be determined
d) cannot be determined
Two ultrasound systems have near zone lengths of 8 cm. At the focus, system S's lateral solution is 3.0 mm, whereas system C's is 5.0 mm. Which system is most likely to appropriately display to two small body structures that lie, one in front of the other, at depths of 8.6 and 9.0 mm. a) system C b) system S c) both have comparable quality d) cannot be determined
d) cannot be determined
What units are used to describe attenuation? a) watts b) watts/cm2 c) macro d) decibels
d) decibels
Which of the following tasks is not performed by the receiver of an ultrasound system? (more than one answer may be correct) a) rectification b) smoothing c) compression d) degaussing
d) degaussing
What two properties establish sound's propagation speed in a given medium? a) elasticity and stiffness b) stiffness and impedance c) conductance and density d) density and stiffness
d) density and stiffness
Which two controls determine a system's temporal resolution? A. frame rate and sector size B. focal zones and sector depth C. propagation speed and frame rate D. depth of view and pulses per image
d) depth of view and pulses per image
Acoustic focusing of an ultrasound beam may create which artifact? A. side lobes B. refraction C. speckle D. enhancement
d) enhancement
One reflector is 5 times deeper than another. The time of flight of sound to the deeper structure is ______the time of flight of the shallower reflector. A) One fifth as much as B) Equal to C) Less than D) Five times more than
d) five times more than
As a general rule, which of the following lists media in increasing order of propagation speeds? a) gas, sold, liquid b) liquid, solid, gas c) solid, liquid, gas d) gas, liquid, solid
d) gas, liquid, solid
Ultrasound is defined as a sound with a frequency of _______. A. greater than 2,000 kHz B. less than 1 kHz C. greater than 10MHz D. greater than 0.02 MHz
d) greater than 0.02 MHz
What is the characteristic of acoustic waves with frequencies of less than 20 Hz when compared with waves having frequencies of more than 20 Hz? a) they travel less efficiently in soft tissue b) they travel more rapidly c) they attenuate more when traveling in soft tissue d) humans can't hear them
d) humans can't hear them
All of the following reduce temporal resolution by increasing the number of pulses per image except: a) increasing the number of foci b) increasing line density c) increasing field of view d) increasing depth of view
d) increasing depth of view
Which of the following terms best describes the relationship between frequency and wavelength for sound traveling in soft tissue? a) reciprocal b) direct c) related d) inverse
d) inverse
An ultrasound wave strikes a boundary between two media. All intensities are measured directly at the boundary. What results when the transmitted intensity is divided by the reflected intensity? A. intensity reflection coefficient B. intensity transmission coefficient C. beam uniformity coefficient D. none of the above
d) none of the above
The final amplitude of an acoustic wave is reduced to one-half of its original value. the final power is ___ the original power. A. the same as B. one-half C. double D. none of the above
d) none of the above
What is the value of the duty cycle for continuous wave ultrasound? a) 100 b) 1% c) 1000% d) none of the above
d) none of the above
Which properties of the piezoelectric crystal of a continuous wave transducer result in the highest emitted acoustic wave frequency? a) thin, high propagation speed b) thick, slow propagation speed c) thin, slow propagations speed d) none of the above
d) none of the above
Attenuation is determined by which of the following factors? a) density and stiffness of the medium b) frequency of sound and propagation speed c) PRF of sound and path length d) path length and frequency of sound
d) path length and frequency of sound
Which of the following focusing techniques is different from the others? a) lens b) curved crystal c) fixed d) phased
d) phased
Which of the following flow patterns is associated with cardiac contraction? a) phasic b) spontaneous c) steady d) pulsatile e) continuous
d) pulsatile
Axial resolution artifacts are due to which of the following? a) multiple reflections b) beam width c) attenuation d) pulse length
d) pulse length
The pulse repetition frequency is the ____________. a) product of the wavelength and propagation speed b) reciprocal of the period c) sum of the pulse duration and listening time d) reciprocal of pulse repetition period
d) reciprocal of pulse repetition period
What are the characteristics of a medium that produces comet tail artifact? a) weak reflectors, closely spaced, low propagation speeds b) strong reflectors, widely spaced, high propagation speeds c) strong reflectors, closely spaced, low propagation speeds d) strong reflectors, closely spaced, high propagation speeds
d) strong reflectors, closely spaced, high propagation speeds
Which component of an ultrasound system exposes a patient to the greatest risk? a) the CRT b) the electric cord c) the pulser d) the transducer
d) the transducer
A sound pulse strikes a boundary between two media with normal incidence. The speed of sound in the two media are very different; however, the impedances of the media are identical. What will happen? a) a big echo will be produced b) a medium echo will result c) a small echo will result d) there will be no echo at all
d) there will be no echo at all
To which of the following do the x-axis of a b-mode, the y-axis of an m-mode, and x-axis of a-mode all relate? a) depth of view b) go time c) echo amplitude d) time of flight
d) time of flight
Which of the following best describes the process described by Snell's law? a) reflection with a normal incidence b) reflection with oblique incidence c) transmission with normal incidece d) transmission with oblique incidence
d) transmission with oblique incidence
The arterial blood pressure of a standing individual is 120 mmHg at the level of the heart. What is the measured blood pressure at a subject's ankle? a) 100 mmHg b) 0 mmHg c) 40 mmHg d) -100 mmHg e) 220 mmHg
e) 220 mmHg
A sonographer is performing a study on a patient and desires superior depth resolution Which of the following changes would create such a system? A. higher frequency B. shorter wavelength C. fewer cycles per pulse D. less ringing E. all of the above
e) all of the above
Which of the following is not associated with laminar flow? a) layered b) normal c) aligned d) smoothed e) chaotic
e) chaotic
Which of the following is not a potential cause of artifact in diagnostic imaging? a) operator error b) equipment malfunction c) patient motion d) ultrasound physics e) none of the above
e) none of the above
The pulse repetition frequency of ultrasound produced by a transducer typical of diagnostic imaging systems A) can be changed by the sonographer B) depends on the medium through which the sound travels C) is unchanged as long as the same ultrasound system is used D) has nothing to do with clinical imaging
A) can be changed by the sonographer
