Principles & Instrumentation Pt 1 Flashcards
Which of the following would lead to misregistration of data and incorrectly placed pixels in a deeper than normal location on the image
A. when less than 75% beam transmission occurs
B. the ultrasound system is calibrated to 1600m/s as the speed of sound in soft tissue
C. the ultrasound system is calibrated to 1450 m/s as the speed of sound in soft tissue
D. a highly reflective media boundary
C
Activation of B-color is used to improve
A. elevational resolution
B. contrast resolution
C. temporal resolution
D. spatial resolution
B, colorized functions are used to improve contrast resolution
When evaluating heavily calcified arteries, what system settings should be increased to improve the demonstration of flow in the vessels
A. frequency and output power
B. persistence and sensitivity
C. color gain and angle of insonation
D. velocity scale and persistence
B
In order to improve spatial resolution and signal-to-noise ratio, _______ uses frequency modulation to manipulate the transmitted beam
A. tissue doppler
B. harmonic imaging
C. spatial compounding
D. coded excitation
D
What system setting should be adjusted to better visualize the possible stone in the ureter posterior to the bladder
A. reduce the rejection settings
B. increase the dynamic range
C. Turn off spatial compounding
D. turn up the overall gain
C, spatial compounding reduces appearance of enhancement and shadowing, turning this off will show the shadowing of the stone
Which of the following is a primary factor in determining the frame rate of an ultrasound system
A. transducer frequency
B. output power
C. axial resolution
D. propagation speed in tissue
D
What is the contrast resolution for a system with a 4 bit memory and 32 dB dynamic range
A. 0.8dB/shade
B. 2dB/shade
C. 8dB/shade
D. 20dB/shade
B, contrast resolution=dynamic range/shades, 4 bit memory will use 16 shades of gray, 32dB/16 shades =2dB/shade
Which of the following imaging techniques would be used to best evaluate the volume of an irregular mass
A. harmonic 2D imaging in at least three imaging planes
B. elastography
C. harmonic 2D imaging in at least two imaging planes
D. 3D rendering
D
If the sonographer decreases the image depth, how will this affect the pulse repetition frequency
A. increase
B. non predictable without information on the pulse duration
C. decrease
D. no effect
A, a decrease in image depth will increase PRF, which increases frame rate
If the reflector is 5cm from the transducer, how long will it take a pulse to reach it
A. 0.3msec
B. 0.03msec
C. 0.6msec
D. 0.06msec
B, Range equation: distance to reflector- velocity x 1/2(time of flight), 5cm=0.5 m, 0.05 m=1540m/s x 1/2, 0.00003s= 1/2, 0.00006s or 0.06ms. The question asks for the time TO the reflector which is half of the round trip time=0.03 ms
What portion of the TGC curve is the deepest region attenuation compensation can occur
A. delay
B. toe
C. heel
D. knee
D
What effect does frequency compounding have on the image
A. reduce speckle artifact
B. increase the transmitted frequency
C. eliminate grating lobe artifact
D. improve temporal resolution
A
Which of the following is least likely to occur with low frequency, high amplitude waves
A. transient cavitation
B. low mechanical index
C. stable cavitation
D. high mechanical index
B
Pulse-echo systems use strength and _____ of the received signal to create the gray scale image. Magnitude and _____ of the signal are used to create the doppler display
A. time of flight, direction
B. intensity, luminance
C. amplitude, location
D. Magnitude, strength
A
Which of the following system functions converts the received signal from radiofrequency form to amplitude form
A. compression
B. demodulation/detection
C. coded excitation
D. bandpass filtering
B
Demodulation is only necessary when
A. high frequency transducers are used
B. the image is displayed in an LCD monitor
C. low frequency transducers are used
D. a television monitor is used to display the image
D
What is the period for a 5MHz transducer
A. 0.2 microseconds
B. 2 microseconds
C. 2 milliseconds
D. 0.02 microseconds
A, 5MHZ=5,000,000Hz, period= 1/frequency
period = 1/5,000,000=0.0000002s or 0.2 microseconds
Which system component converts the scan line data into image format for display
A. image processor
B. beam former
C. signal processor
D. scan converter
A
Frame rates can be improved by the use of what signal processing technique
A. demodulation
B. parallel processing
C. autocorrelation
D. fast fourier transformation
B
Which of the following parameters is NOT operator adjustable
A. mechanical index
B. frequency
C. intensity
D. PRF
B
While scanning, you decide to increase the image contrast. What console control will be adjusted
A. increase overall gain
B. increase compression
C. reduce demodulation
D. increase rejection
D
During an ultrasound exam of the liver, you change from a 5MHz transducer to a 3MHz transducer. How does the propagation speed through the liver change
A. increases
B. decreases
C. remains constant
D. unable to determine
C
What beam formation technique is used to produce the sector field of view in a phased array transducer
A. mechanical focusing
B. mechanical steering
C. electronic focusing
D. electronic steering
D
which of the following will not affect the signal to noise ratio on a 2D image
A. frequency compounding
B. temporal compounding
C. harmonic imaging
D. spatial compounding
B
When you change the PRF, this adjusts
A. # cycles per pulse
B. # pulses emitted per second
C. # cycles emitted per second
D. none of the above
B
Which of the following console controls will adjust the pulse duration
A. output power
B. imaging depth
C. adding a focal zone
D. none of the above
D, the pulse duration cannot be changed unless a new transducer is selected
If the amplitude of the ultrasound wave decreases by 1/2 with a constant beam area, what happens to the intensity of the beam
A. decreases to 25% of original value
B. increases by a factor of 4
C. doubles
D. decreases to 50% of original value
A (decreases by factor of 4)
The range equation is used to determine the
A. sensitivity of the US system
B. distance to a reflector
C. dynamic range of the US system
D. focal depth
B
Which of the following correctly lists how to estimate the volume of a structure on 2D imaging
A. length x width x height
B. length x width x 0.523
C. length x width x height x 0.523
D. length x width x height x 100%
C
Vessel wall thickness and plaque morphology are best evaluated in 2D when the beam is at what incident angle to the vessel
A. 0 degrees
B. 45 degrees
C. 60 degres
D. 90 degrees
D
Which of the following would brighten the image without affecting beam intensity
A. decrease monitor brightness
B. decrease rejection
C. increase the amplitude of transmitted sound
D. increase the amplitude of reflected sound
D
Which of the following correctly describes apodization
A. it is performed by maximizing the voltage of the central elements and reducing the voltage to the outer elements
B. It is a post processing function that adjusts contrast resolution
C. it is a post processing function that adjusts temporal resolution
D. it is used to remove the high frequency reflections outside the bandwidth
A
If the power of the beam is 24mW and the FOV is 2cm x 3cm, what is the average beam intensity
A. 0.4mW/cm^2
B. 4mW/cm^2
C. 7mW/cm^2
D. 0.7mW/cm^2
B, intensity= power/area, intensity= 24mW/6cm^2= 4mW/cm^2
The peak amplitude of the vertical spike on the A mode display corresponds to
A. the time to the reflector
B. the distance to the reflector
C. the strength of the reflection
D. the time to and from the reflector
C
Which of the following will improve lateral resolution at all depths on the image
A. decrease probe frequency
B. dynamic receive focusing
C. use >3 focal zones
D. dynamic transmit focusing
B
You are performing a liver ultrasound using the intercostal window and the entire image is very bright. What is the best way to adjust the image to the appropriate brightness level
A. adjust the far field TGCs
B. adjust the near field TGCs
C. adjust the power output
D. adjust the overall gain
C
Amplification of the received signal occurs in the
A. beam former
B. signal processor
C. image processor
D. image former
A
When harmonic imaging is turned on, it primarily improves _______ resolution
A. axial
B. temporal
C. lateral
D. contrast
C
The horizontal axis on the M mode represents the _____
A. motion
B. time
C. depth
D. frequency shift
B
The vertical axis on the m mode display represents the _______
A. depth of the reflector
B. motion of the structure
C. time
D. frequency shift
A
Increasing the edge enhancement setting will
A. increase image contrast
B. improve contrast resolution
C. amplify reflections on the edges of the image
D. produce a smoother image
A
If you increase the sector angle from 45 to 90 degrees and reduce the line density by 50%, what happens to the frame rate
A. it is reduced to 1/4 the original frame rate
B. unchanged
C. it doubles
D. it is reduced to 1/2 the original frame rate
B
Which of the following is a true statement regarding tissue harmonic imaging
A. reduces grating lobe and side lobe artifacts
B. degrades axial resolution in near field
C. improves elevational resolution in far field
D. increases beam width with improving lateral resolution
A
Harmonic frequencies are generated
A. as the sound wave travels through the medium
B. from the edges of each piezoelectric element
C. as the reflected wave hits new tissue boundaries on the return path
D. from the constructive and destructive interference
A
When using virtual beam forming the ultrasound beam is described as
A. high volume
B. cylindrical
C. rectangular
D. laser-thin
D
What part of the beam former creates the digital echo signal that is sent to the signal processor
A. digital to analog conerter
B. pulser
C. amplifier
D. analog to digital converter
D
List the parts of the beam former in the order they function to produce and receive sound waves
A. summer, pulse delays, pulser, echo delays, transmit/receive switch, amplifier, analog to digital converter, echo delays
B. pulse delays, pulser, transmit/receive switch, amplifier, echo delays, analog to digital converter, summer
C. pulser, pulse delays, transmit/receive switch, analog to digital converter, echo delays, summer, amplifier
D. pulser, pulse delays, transmit/receive switch, amplifier, analog to digital converter, echo delays, summer
D
Which of the following is an advantage of VBF over traditional pulse echo imaging
A. VBF allows for 5 or more transmit focal zones per image with acceptable temporal resolution
B. VBF allows for simultaneous real time gray scale, color and spectral doppler display
C. VBF does not require a sonographer to operate the transducer
D. VBF produces a lower intensity beam than a traditional PEI system
B
Which of the following is a function of the signal processor
A. filtering and compression
B. amplification and compression
C. steering and focusing
D. apodization and aperture
A
Which of the following correctly describes dynamic receive focusing
A. can only be performed in single element transducers
B. adjusted by sonographer by adding or removing focal zones
C. allows focusing at multiple depths on the image
D. it is a function of the pulser
C
Which of the following causes range ambiguity artifact
A. high PRF
B. electrical interference
C. refraction
D. element damage
A
While scanning soft tissue, the reflected wave returned to the transducer in 0.05 msec. How far away is the reflector
A. 8cm
B. 0.4cm
C. 8mm
D. 4cm
distance to reflector = velocity x 1/2 (time of flight) distance= 1540 m/s x 1/2 (.00005s), distance= 0.04m or 4 cm
Which system control will simultaneously enhance far field echoes and diminish near field echoes
A. rejection
B. threshold
C. overall gain
D. time gain compensation
D
An advantage of virtual beam forming over traditional pulse echo instrumentation is
A. one transducer can be used for all exam types
B. no transmit focusing is needed
C. the risk of bioeffects is reduced by 50% or greater
D. no receive focusing is needed
B
Bandpass filtering is a function performed in the
A. beam former
B. image processor
C. signal processor
D. pulser
C
If the input power is 0.05mW and the output power is 500mW, what is the gain
A. 100dB
B. 40dB
C. 20dB
D. 20dB
B
Increasing the frequency improves _______, _______ and _______
A. axial resolution, lateral resolution, beam width
B. frequency, intensity, beam depth
C. depth of penetration, beam width, axial resolution
D. lateral resolution, intensity, beam width
A
Which of the following describes a primary difference between virtual beam forming and traditional pulse echo imaging
A. VBF requires only one transducer for all types of ultrasound exams
B. VBF requires only one PE element, which allows for a very lightweight transducer
C. VBF allows for cordless transducers
D. VBF does not use transmit focusing like pulse echo imaging
D
Increasing _______ will improve detail resolution the most on the lateral sides of the image
A. beam width
B. overall gain
C. line density
D. image depth
C
Which of the following can change the image data displayed on an archived exam on the ultrasound system
A. turn off the harmonic imaging
B. change the gray map used to create the image
C. change the transducer frequency used to create the image
D. change the placement pf the doppler cursor
B
Even and odd harmonic frequencies are created by
A. variable timing of the firing of the piezoelectric elements
B. turbulent flow in a blood vessel
C. alternating current to different piezoelectric elements in the transducer transducer array
D. non-linear sound wave propagation
D
Which of the following will improve contrast resolution
A. receive focusing
B. coded excitation
C. using a stand off pad
D. decreasing frequency
B
If the input power is 0.5mW and the output power is 500mW, what is the gain
A. 20dB
B. 30dB
C. 100dB
D. 40dB
D, 0.05mW x 10000 = 500mW= 40dB
If the sonographer decreases the image depth, how will this affect the PRF
A. no effect
B. increase
C. not predictable without information on the pulse duration
D. decrease
B
What effect does frequency compounding have on the image
A. reduce speckle artifact
B. eliminate grating lobe artifact
C. improve temporal resolution
D. increase the transmitted frequency
A
What component of the beam former protects the sensitive circuitry of the amplifier
A. summer
B. transmit/receive switch
C. pulse delays
D. transducer
B
Which of the following is the correct listing for the number 28 as a binary number
A. 011010
B. 011100
C. 001110
D. 100111
B
The horizontal axis on the m-mode represents the ______
A. motion
B. depth
C. time
D. frequency shift
C
Increasing the edge enhancement setting will
A. amplify reflections on the edges of the image
B. improve contrast resolution
C. produce a smoother image
D. increase image contrast
D
Which of the following system functions converts the received signal from radiofrequency form to amplitude form
A. compression
B. bandpass filtering
C. demodulation/detection
D. coded excitation
C
Which of the following is a primary factor in determining the frame rate of an ultrasound system
A. axial resolution
B. output power
C. transducer frequency
D. prop speed in tissue
D
What part of the ultrasound system is responsible for changing the PRF with changes in image depth
A. pulser
B. digital to analog converter
C. fast Fourier transformer
D. elevational resolution
A
Harmonic frequencies are generated
A. as the sound wave travels through a medium
B. from constructive and destructive interference
C. from the edges of each piezoelectric element
D. as the reflected wave hits new tissue boundaries on the return path
A
Amplification of the received signal occurs in the
A. beam former
B. signal processor
C. image former
D. image processor
A
Increasing the number of bits per pixel in an image memory will improve the
A. temporal resolution
B. detail resolution
C. elevational resolution
D. contrast resolution
D
Which of the following system controls reduces noise and smooths the image using frame averaging
A. pixel interpolation
B. compression
C. demodulation
D. persistence
D
The ______ is defined as the time it takes for one pulse to occur
A. PRF
B. pulse duration
C. period
D. SPL
B
Bandpass filtering is a function performed in the
A. signal processor
B. beam former
C. image processor
D. pulser
A
Which of the following best describes the difference between 3D ultrasound imaging and 4D ultrasound imaging
A. 3D imaging was developed to demonstrate structural anomalies of the fetus while 4D imaging was developed to demonstrate cardiac anomalies in pediatric patients
B. 4D imaging provides real time display of 3D images
C. 4D imaging provides the ability to doppler while imaging in 3D
D. 4D imaging was developed to demonstrate structural anomalies of the fetus while 3D imaging was developed to demonstrate cardiac anomalies in pediatric patients
B
What part of the beam former creates the digital echo signal that is sent to the single processor
A. amplifier
B. digital to analog converter
C. analog to digital converter
D. pulser
C
Which of the following instrument controls does the sonographer use to adjust the amplitude of a reflected of sound wave
A. swept gain
B. receiver gain
C. transmit gain
D. rejection
B
Which of the following correctly describes dynamic aperture
A. will increase the appearance of lobe artifact
B. uses more crystals to receive deep reflections than to shallow reflections
C. type pf transmit focusing
D. also called dynamic frequency tuning
B
Which of the following system functions converts the received signal from radio frequency form to amplitude form
A. demodulation/detection
B. coded excitation
C. bandpass filtering
D. compression
A
Which of the following causes range ambiguity artifact
A. refraction
B. electrical damage
C. high PRF
D. electrical interference
C
Harmonic frequencies are generated
A. from constructive and destructive interference
B. from the edges of each piezoelectric element
C. as the reflected wave hits new tissue boundaries on the return path
D. as the sound wave travels through the medium
D
While scanning soft tissue, the reflected wave returned to the transducer in 0.05msec. How far away is the reflector
A. 8cm
B. 0.4cm
C. 8mm
D. 4cm
D
What effect does frequency compounding have on the image
A. reduce speckle artifact
B. increase the transmitted frequency
C. improve temporal resolution
D. eliminate grating lobe artifact
A
An advantage of VBF over traditional pulse echo instrumentation is
A. one transducer can be used for all exam types
B. the risk of bioeffects is reduced by 50% or greater
C. no receive focusing is needed
D. no transmit focusing is needed
D
_______ is the process that is performed in the beam former where the output voltage is varied to decrease the formation of lobe artifacts
A. apodization
B. autocorrelation
C. quadrature phase detection
D. spectral analysis
A
Which of the following best describes the difference between 3D ultrasound imaging and 4D ultrasound imaging
A. 4D imaging provides real time display of 3D images
B. 4D imaging provides the ability to Doppler while imaging in 3D
C. 4D imaging was developed to demonstrate structural anomalies of the fetus while 3D imaging was developed to demonstrate cardiac anomalies in pediatric patients
D. 3D imaging was developed to demonstrate structural anomalies of the fetus while 4D imaging was developed to demonstrate cardiac anomalies in pediatric patients
A
Which of the following techniques can improve contrast resolution to aid in the visualization of an isoechoic mass
A. switch to a lower frequency transducer
B. turn on harmonic imaging
C. increase the slice thickness
D. decrease the number of focal zones
B
Increasing the frequency improves ______, ______ and _____
A. depth of penetration, beam width, axial resolution
B. frequency, intensity, beam width
C. lateral resolution, intensity, beam width
D. axial resolution, lateral resolution, beam width
D
Bandpass filtering is a function performed in the
A. pulser
B. beam former
C. signal processor
D. image processor
C
Increasing the edge enhancement setting will
A. amplify reflections on the edges of the image
B. increase image contrast
C. produce a smoother image
D. improve contrast resolution
B
The amount of compensation necessary for different echoes varies with reflector
A. density
B. impedance
C. size
D. depth
D
Which of the following imaging techniques would be used to best evaluate the volume of an irregular mass
A. 3D rendering
B. harmonic 2D imaging in at least three imaging planes
C. harmonic 2D imaging in at least two imaging planes
D. elastography
A
Which of the following is a primary factor in determining the frame rate of an ultrasound system
A. transducer frequency
B. prop speed in tissue
C. output power
D. axial resolution
B
Edge enhancement, pixel interpolation, persistence and 3D image acquisition are all types of
A. spatial compounding
B. coded excitation
C. preprocessing
D. postprocessing
C
