Part 5 Flashcards
What display method below will help you to demonstrate flow turbulence with color Doppler?
Variance
Color flash artifact is obscuring the anatomy of interest in an exam of the abdominal aorta. What can you do to reduce impact of the flash?
Increase the wall filter
The nyquist limit describes which of the following?
Sampling frequency needed for detecting the Doppler signal unambiguously
Spectral analysis is used to
Determine the distribution and magnitude of frequency shifts in the reflected Doppler signal
Which answer provides the best explanation for the reason that the frame rate decrease when color Doppler is activated?
More pulses are fired on each line of sight
The Doppler frequency shift is in the different between the
Received frequency and the transmitted frequency
You will see aliasing of the Doppler spectrum occurs whenever the frequency shift exceeds
1/2 the PRF
When you measure the width of a point target in a tissue-mimicking phantom, you are evaluating
lateral resolution
String test objects are used to evaluate
Doppler accuracy
What can you test with a Doppler flow phantom?
All of the above (Range- gate accuracy, spectral Doppler velocity accuracy, color Doppler penetration)
Which of the following should be regularly checked as a component of quality control program?
All of the above (system penetration, image uniformity, assurance of electrical safety, distance measurement accuracy)
What is meant by the dead zone in performance testing?
Distance from the transducer to the first identifiable echo
In an ultrasound phantom, the targets typically used for measuring axial resolution are
Closely spaced targets of varying distances
What is the order in which the signal travels in the ultrasound system?
Transducer, receiver scan converter, display
The conversion of an incident pressure wave to an electrical signal is the
PZT effect
Which of the following can not be evaluated with a tissue -equivalent phantom?
temp resolution
What array transducer tries all of the elements for acoustic scan line, using small time delays to steer the beam?
Phased array
Which image technique may increase visualization of the reflections from blood flow on the real-time ultrasound image?
Tissue harmonic imaging
Which of the following helps to improve the axial resolution in a B-mode image?
Increased bandwidth
A type of sonographic imaging that transmits two pulses of opposite phase in rapid succession so they can be cancelled out upon reception is termed
Pulse inversion harmonics
Which of the following best describes the Doppler frequency shift when you encounter high velocities within a vessel?
Frequency shift is increased
What must be known to covert the Doppler shift frequency spectrum into velocities
All of the above (Doppler frequency, angle of incidence, speed of sound in tissue, ultrasound frequency)
Which of the following occurs when you lower the pulse repetition frequency?
The Nyquist limit is decreased
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
Lung
The propagation speed for sound is lowest in which of the following biologic tissues?
a) fat
b) blood
c) muscle
d) bone
e) liver
fat
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
Stifness
An echo from which one of the following sound reflectors is most dependent on the angle of incidence?
a) rayleigh scatterer
b) diffuse reflector
c) specular reflector
d) acoustic scatterer
e) nonspecular reflector
specular reflector
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, one-half the wavelength
d) one-half the attenuation rate, double the wavelength
e) one-half the attenuation rate, one-fourth the wavelength
A
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
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 degrees
c
If sound waves of 3 MHz, 5MHz, and 10 MHz are transmitted through the same 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
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 standoff pad
d) increase TGC
E) decrease transmit frequency
E
The maximum cyclical change in a quantity is known as:
a) amplitude
b) pressure
c) power
d) intensity
e) decibel
a
If the number 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
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
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
You are imaging with a 5 MHz linear array transducer. What sound parameters slays constant as the beam propagates through the tissue?
a) frequency
b) intensity
c) amplitude
d) wavelength
e) none of the above
e
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
Which of the following would increase the spatial pulse length?
a) increased PRF
b) decreased number of transmit pulses per frame
c) increased number of transmit pulses per second
d) increased number of transmit pulses per line
e) increased number of cycles per pulse
e
Spatial resolution is determined by which of the following? a. the number of bits per pixel b. spatial pulse length c. frame rate d.the number of pixels per inch e beam diameter
d
Which of the following receiver functions cant be adjusted by the sonographer?
a. compensation
b. demodulation
c. compression
d. amplification
e. threshold
b
Which of the following transducers will have the shallowest focus?
a. high frequency, large diameter
b. high frequency, small diameter
c. low frequency, large diameter
d. low frequency, small diameter
c
Enhancement artifact appears on an ultrasound scan. Which of the following statements is true about the structure immediately above the artifact?
a. attenuation properties are too low
b. speed of sound is too high
c. speed of sound is too low
d. it is hypo echoic
e. there is too little absorption
a
The image on an ultrasound system’s display is too bright. Which of the following techniques is best to correct this problem?
a. decrease receiver gain
b. decrease reject
c. adjust time gain compensation
d. decrease output power
e. increase threshold
d
A pulse is emitted by a transducer and is traveling in soft tissue. The go-return time, or time-of-flight, of a sound pulse is 130 microseconds. What is the reflector depth?
a. 10 cm
b. 130 mm
c. 10 m
d. 10 mm
e. 13 cm
a
How much time is required for a sound pulse to travel round trip to and from a reflector that is 2 cm deep in soft tissue?
a. 26 ms
b. 26 us
c. 26 s
d. 0.26 s
e. 2 s
b
Which of the following terms does not belong with the others?
a. plug flow
b. layered flow
c. turbulent flow
d. parabolic flow
e. laminar flow
c
Which of these biologic tissues will sound waves propagate most quickly?
a. fat
b. amniotic fluid
c. tendon
d. lung
e. bood
c
Which of the following is most likely to create cavitation?
a. high peak pressure and short wavelength
b. high peak rarefraction pressure and low frequency
c. high peak pressure and high frequency
d. low peak pressure and long wavelength
b
An ultrasound system is imaging to a depth of 10 cm. Which of the following will be different on a single image at depths of 2cm, 5cm and 10 cm?
a. contrast resolution
b. temporal resolution
c. lateral resolution
d. axial resolution
c
Quality assurance studies should be performed
a. daily
b. weekly
c. routinely
d. 1 week prior to joint commission review
e. monthly
c
When a sound beam bounces off a reflector at an oblique angle, the angle of reflection is equal to the angle of incidence. What is this called? a. edelman's law b. snell's law c. there is no special name for this d. bernoulli's principle poiseullie's law
c
The general mechanism which creates harmonics is called
a. non-linear behavior
b. bernoulli flow
c. turbulent behavior
d. nyquist limits
e. poiseulle’s flow
a
Which of the following best describes a linear sequential array transducer?
a. dynamic receive focusing, rectangular shaped image
b. mechanical steering, electronic focusing, trapezoidal shaped image
c. electronic steering, electronic focusing, sector shaped image
d. electronic steering, fixed focusing, trapezoidal shaped image
e. electronic steering, electronic focusing, trapezoidal shaped image
a
Which of the following is the special analysis technique of choice for pulsed and continuous wave Doppler?
a. fast fourier transform for pulsed Doppler; autocorrelation for continuous wave Doppler
b. correlation function for pulsed Dopple, zero crossing detection for continuous wave Doppler
c. autocorrelation for pulsed Doppler; fast fourier transform for continuous wave Doppler
d. fast fourier transform
e. autocorrelation for pulsed Doppler and continuous wave Doppler
d
Which of the following choices determines the signal amplitude in the transducer of an ultrasound system?
a. persistence
b. edge enhancement
c. post processing
d. reflected intensity of the sound bream
e. demodulation
d
Which of the following factors determine the spatial resolution of a monitor?
a. the number of the bits per inch
b. the number pixels per inch
c. the number of lines per frame
d. dynamic range
e. the number of pixels per bit
c
which of the following is associated with power mode Doppler?
a. high sensitivity and high frame rates
b. lower sensitivity and good temporal resolution
c. good temporal resolution and flash artifact
d. poor temporal resolution and flash artifact
e. flash artifact and reduced sensitivity
d
Which of the following controls on an ultrasound system’s console will reduce ghosting artifact?
a. wall filter
b. Nyquist limit
c. overall gain
d. persistence
e. impedance
a
Which of these terms does not belong with the others?
a. short pulse repetition period
b. shallow imaging
c. high PRF
d. short pulse duration
e. high duty favor
d
What determines whether reflection will occur when a sound beam strikes a boundary at normal incidence?
a. propagation speed differences
b. elasticity differences
c. incident differences
d. density differences
e. impedance differences
e
All of the following are limitations of analog scan converters EXCEPT:
a. image deterioration over time
b. low spatial resolution
c. image fade
d. image flicker
e. instability
b
Which of these choices has the greatest effect upon depth of view?
a. spatial pulse length
b. acoustic impedance
c. transducer output
d. pulse repetition period
e. pulse duration
d
A sound beam is created by a single, disc- shaped crystal. Which of these beams has the shallowest focus?
a. 2 MHz, 9 mm diameter
b. 6 MHz, 9 mm diameter
c. 5 MHz, 12 mm diameter
d. 5 MHz, 14 mm diameter
e. 7 MHz, 9 mm diameter
a
All of the following statements regarding the hemodynamics of a stenosis are true EXPECT:
a. turbulence is evident downstream from the stenosis
b. pressure is highest upstream from the stenosis
c. flow direction changes as blood flows into and out of the stenosis
d. velocity is highest downstream from the stenosis
e. in cases of significant stenosis, the flow pattern downstream from the stenosis may be steady rather than pulsatile
d
Which of these statements is most true of a 25 MHz sound pulse?
a. highly attenuating, short spatial pulse length
b. short wavelength, lowly attenuating, slow speed
c. highly attenuating, extremely fast propagation speed, long wavelength
d. lowly attenuating, very deep half value later, short period.
e. long period, short wavelength
a
All of the following terms are associated with PACS systems EXECPT:
a. easy access to archived studies
b. large capacity storage devices
c. store and forward telemedicine
d. analog replay
d
An annular phase array transducer is different than a linear phased array system in which way?
a. the linear can have multiple focal zones
b. the linear has higher pulse repetition frequency
c. the annular can create a sector shaped image
d. the annular is steered mechanically
e. the linear is steered mechanically
d
With phased array transducers, tiny tiny delays are used to steer the sound beams in different directions. Which components of an ultrasound system creates these tiny delays?
a. preprocessor
b. transducer
c. beam former
d. receiver
e. demodulator
c
Which of the following best describes the empirical approach to the study of bioeffects?
a. exposure- response
b. causation-reaction
c. risk-benefit
d. cause-effect
e. effect-microstreaming
a
Which of the following steps is performed just prior to storage of image data in a digital scan converter?
a. read magnification
b. rectification
c. A-to-D conversion
d. D-to-A conversion
e. demodulation
c
What does a hydrophone measure?
a. acoustic output of an ultrasound imaging system
b. dynamic range of an ultrasound imaging system
c. receiver gain of an amplifier
d. attenuation of sound in soft tissue
e. doppler frequency of a pulsed wave system
a
What is the significance of grey scale variation in the spectrum of a pulsed wave Doppler display?
a. it represents the number of red blood cells creating the reflection
b. it represents the convergence of red blood cell lamina
c. it represents the velocity of red blood cells
d. it represents the speed of red blood cells
e. it determines the ensemble length
a
The interaction of microscopic bubbles and ultrasound form the basis for cavitation bioeffects. Which of the following forms of cavitation are most likley to produce micro streaming in the intracellular fluid and shear stresses?
a. transient cavitation
b. stable cavitation
c. inertial cavitation
d. active cavitation
e. normal cavitation
b
Which of the following best describes the features of a sound wave and medium that determine the speed of sound in the medium?
a. elasticity of the medium and frequency of the sound beam
b. density of the medium and stiffness of the medium
c. density of the medium and power of the sound beam
d. pulse repetition period of the sound wave and density of the medium
e. stiffness of the medium and elasticity of the medium
b
In which of these media will sound travel the slowest?
a. high density, high stiffness
b. low density, high stiffness
c. high density, low stiffness
d. low density, low stiffness
e. high density, low elasticity
c
What conditions are required for refraction to occur at a boundary between two media?
a. oblique incidence and different densities
b. oblique incidence and different impedances
c. different densities and different stiffness
d. oblique incidence and different speeds
e. normal incidence and different speeds
d
All of the following will improve temporal resolution EXCEPT:
a. increased line density
b. shallower depth of view
c. higher frame rate
d. slower speed of sound in a medium
e. single rather than multi focus
a
Which of the following controls on an ultrasound system’s console will reduce ghosting artifact?
a. impedance
b. overall gain
c. wall filter
d. nyquist limit
e. persistence
c
All of the following artifacts place the erroneous reflection below the true reflector EXPECT:
a. comet tall
b. side lobe
c. reverberation
d. mirror image
e. ring down
b
All of the following operational settings are related to improved temporal resolution EXCEPT:
a. single focus
b. narrow sector
c. low line density
d. shallower imaging
e. increased frequency
e
In a B- mode display, which of the following CRT inputs are used with the amplitude of the reflection?
a. m- axis
b. y-axis
c. x-axis
d. time base axis
e. z-axis
e
Which of the following is associated with power mode Doppler?
a. flash artifact and reduced sensitivty
b. poor temporal resolution and flash artifact
c. lower sensitivity and good temporal resolution
d. high sensitivity and high frame rates
e. good temporal resolution and flash artifact
b
what is the accuracy of reflector depth position on an A-mode, B-mode or M-mode display called?
a. horizontal calibration
b. speed error artifact
c. range resolution
d. depth calibration
e. axial resolution
d
Which of these factors has the greatest influence of pulse repetition period?
a. attenuation of the sound beam
b. display’s dynamic range
c. thickness of the PZT cystal
d. impedance of the medium
e. display depth
e
Which of the following user-adjustable controls has the single greatest affect upon Doppler color jet size?
a. red blood cell velocity
b. doppler/echo read write priority
c. color Doppler gain settings
d. packet size
e. ensemble length
c
What is the greatest advantage of one and one-half dimensional array transducers?
a. improved lateral resolution
b. improved temporal resolution
c. improved slice thickness resolution
d. improved axial resolution
e. improved contrat resolution
c
All of the following are pimarily used to change the overall brightness of an entire image EXCEPT:
a. receiver gain
b. compensation
c. output power
d. amplification
e. overall gain
b
In a real time scanner, which of these choices determines the maximum frame rate?
a. attenuation coefficient
b. pixel size
c. beam diameter
d. lateral resolution
e. depth of view
e
Which of the following factors has the greatest influence on temporal resolution?
a. wavelength of sound and propagation speed in the medium
b. propagation speed of sound in the medium and the imaging depth
c. frequency of sound and the propagation speed of sound in the medium
d. output power and frequency
b
With an unfocused transducer, what is the area from the face of the transducer to where the beam diverges called?
a. focal length
b. far field
c. near field
d. focal zone
c
A circular hyperechoic structure is located at a depth of 5cm. The structure has abnormally low attenuation and the speed of sound in the mass is 1,400 m/s. Which of the following artifacts is most likely to appear beneath the structure?
a. reflectors beneath the structure are hypoechoic and too shallow
b. reflectors beneath the structure appear abnormally hyperechoic and too shallow
c. subdicing
d. reflectors beneath the structure appear abnormally deep in the image
e. refraction artifact
d
Which of the following forms of focusing is achieved during reception?
a. internal
b. lens
c. dynamic aperture
d. excitation phasing
e. external
c
Which of the following best describes annular array transducer?
A excellent lateral resolution, diminished axial resolution, sector shaped image
B excellent spatial resolution, diminished lateral resolution, sector shaped image
C excellent lateral resolution, diminished temporal resolution, sector shaped image
D excellent contrast resolution, diminished temporal resolution, sector shaped image
E excellent axial resolution, diminished temporal resolution, rectangular shaped image
a
All of the following statement are true regarding temporal resolution EXCEPT:
A improved temporal resolution occurs with a narrow sector
B decreased temporal resolution is associated with a shorter pulse duration
C increased temporal resolution is associated with a higher PRF
D increased line density is associated with diminished temporal resolution
E diminished temporal resolution is related to multifocusing
b
Which of these statements is the most true of a 25 MHz sound pulse?
A short wavelength, lowly attenuating, slow speed
B long period, short wavelength
C lowly attenuating, very deep half value layer, short period
D highly attenuating, extremely fast propagation speed, long wavelength
E highly attenuating, short spatial pulse length
e
Which of the following is the correct order of receiver operation?
A attenuation, amplification, TGC, gain, threshold
B amplification, compression, compensation, demodulation, reject
C amplification, demodulation, reject
D reject, demodulation, compression, compensation, amplification
E amplification, compensation, compression, reject, demodulation
d
Which of the following is associated with power mode Doppler?
A high sensitivity and high frame rates
B flash artifact and reduced sensitivity
C lower sensitivity and good temporal resolution
D good temporal resolution and flash artifact
E good temporal resolution and flash artifact
e
All of the following are true of normal cavitation Except:
A it is consistent with shock waves
B temperatures in the thousands of degrees is created
C harmful; bioeffects are commonly observed
D only 10% increase in pressure is needed to convert to this form stable cavitation
E It is also known as inertial cavitation
c
In which of these media will sound travel the slowest? A low density, low stiffness B low density, low elasticity C low density, high stiffness D high density, high stiffness E high density, low stiffness
e
The following transducers have a constant output power. Which of the following have the lowest SPTA intensity at a depth of one near zone? A 4 MHz, 10 mm diameter B 4 MHz, 4 mm diameter C 4 MHz, 9 mm diameter D 4 MHz, 12 mm diameter E 4 MHz, 6 mm diameter
d
