4. Instruments Flashcards
The ultrasound PRF is equal to the voltage _____ repetition frequency of the pulser.
a. amplitude
b. pulse
c. period
d. duration
b. pulse
Increased voltage amplitude produced by the pulser increases the _____ and _______ of ultrasound pulses produced by the transducer.
a. amplitude, intensity
b. amplitude, frequency
c. frequency, period
d. frequency, intensity
a. amplitude, intensity
If a 6 MHz transducer images to a depth of 10 cm, to avoid range ambiguity, the max PRF permitted is _____.
a. 7.7 kHz
b. 6.0 kHz
c. 10.0 kHz
d. 1.54 MHz
a. 7.7 kHz ( a min echo reception time of 130 us is required)
Functions performed by the signal processor include ______, ______ and ______.
a. amplification, digitizing, filtering
b. amplification, filtering, digital-to-analog conversion
c. amplification, filtering, compression
d. filtering, detection, compression
d. filtering, detection, compression
If the input voltage to an amplifier is 1 mV and the output voltage is 10 mV, the voltage amplification ratio is ______. The power ratio is _____. The gain is ____ dB.
a. 10, 20, 30
b. 10, 100, 100
c. 10, 100, 20
d. 10, 10, 10
c. 10, 100, 20
Time gain compensation is accomplished in the _______.
a. pulse
b. beamformer
c. signal processor
d. postprocessor
e. image processor
b. beamformer
Compensation takes into account reflector _______.
a. impedance
b. size
c. amplitude
d. depth
d. depth
Compensation amplifies echoes differently, according to their arrival _______.
a. times
b. positions
c. directions
d. strengths
a. times
Compression decreases the ______ range to a range that the ____ and human _______ can handle.
a. frequency, instrument, intelligence
b. dynamic, display, vision
c. amplitude, display, hearing
d. dynamic, pulser, vision
b. dynamic, display, vision
If a display has a dynamic range of 20 dB and the smallest voltage it can handle is 200 mV, then the largest voltage it can handle is __ V
a. 20
b. 2.0
c. 0.2
d. 0.02
b. 2.0
Detection converts voltage pulses from _____ form to ______ form.
a. ultrasound, infrasound
b. infrasound, ultrasound
c. radio frequency, amplitude
d. ultrasound, radio frequency
c. radio frequency, amplitude
Filtering widens bandwidth. T or F?
False
Filtering is accomplished in the ________.
a. pulser
b. beamformer
c. signal processor
d. postprocessor
e. image processor
c. signal processor
The compression or dynamic range control reduces the range of echo amplitudes displayed by reducing the weakest to ________ and/or the strongest ones to the ______ value and assigning the others to increasing values. This produces a(n) _______ contrast image with elimination of weakest and maximizing of strongest echoes.
a. minimum, maximum, higher
b. zero, 100, zero
c. zero, maximum, higher
d. 10, 100, optimum
c. zero, maximum, higher
If the beam-former output to the transducer is reduced by 3, 6, or 9 dB, the ultrasound pulse output intensity is reduced by __%, __%, or __%, respectively.
a. 50, 75, 87.5
b. 50, 25, 12.5
c. 6, 12, 18
d, 33, 66, 99
a. 50, 75, 87.5
One watt is ___ dB below 100 W.
a. 1
b. 2
c. 10
d. 20
d. 20
One watt is __ dB above 100 mW.
a. 1
b. 2
c. 10
d. 20
c. 10
If the input power is 1 mW and the output is 10,000 mW, the gain is ___ dB.
a. 10
b. 20
c. 30
d. 40
d. 40
If an amplifier has a gain of 15 dB, the ratio of output power to input power is _____.
a. 15
b. 22
c. 30
d. 32
d. 32
The contrast resolution for an instrument that has an echo dynamic range of 43 dB and 32 shades is ___ dB per shade.
a. 1.3
b. 3.2
c. 4.3
d. 32
e. 43
a. 1.3
The contrast resolution for an instrument that has a 6 bit memory and a 45 dB echo dynamic range is ___ dB per shade.
a. 0.3
b. 0.5
c. 0.7
d. 0.9
e. 6
c. 0.7
Typical image pixel dimensions are _______.
a. 640 x 128
b. 16 x 64
c. 100 x 100
d. 512 x 1540
e. 512 x 384
e. 512 x 384
___ total memory elements are required for a 100 x 100 pixel, 5 bit digital memory.
a. 500
b. 1000
c. 5000
d. 10,000
e. 50,000
e. 50,000
Memories of ____ bits per pixel are common in ultrasound today.
a. 4 to 8
b. 4 to 6
c. 6 to 8
d. 5 to 7
e. 4 to 5
c. 6 to 8
Digital memories store _______.
a. logarithms
b. electric magnetism
c. electric current
d. electric charge
e. numbers
e. numbers
_______ is commonly controllable by the operator.
a. postprocessing
b. pixel matrix
c. bits per pixel
d. digitization
e. all of the above
a. postprocessing
In binary numbers, how many symbols are used?
a. 0
b. 1
c. 2
d. 4
c. 2 (0 and 1)
The term binary digit is commonly shortened into the single word ____.
a. bigit
b. binit
c. bidig
d. bit
d. bit
Each binary digit in a binary number is represented in the memory by a memory element, which, at any time, is in one of ______ states that are _____ or _______.
a. 2, on, off
b. many, odd, even
c. 4, high, low
d. 10, odd, even
a. 2, on, off
What decimal number does the binary number 11001 represent?
a. 15
b. 20
c. 25
d. 35
c. 25
A B scan presents a cross section through the _____ plane.
a. longitudinal
b. transverse
c. elevational
d. scan
d. scan
A display that shows various echo strengths as different brightnesses is called a _____-_______ or ____ _____ display.
a. gray-scale, B mode
b. cross-sectional, anatomic mode
c. sono-scan, sectional mode
d. gray-mode, square pixel
a. gray-scale, B mode
The ________ _______ stores the gray-scale image and allows it to be displayed on a computer monitor.
a. signal processor
b. preprocessor
c. postprocessor
d. image memory
d. image memory
If the PRF of an instrument is 1 kHz and it displays (single focus) 25 frames per second, there are __ lines per frame.
a. 20
b. 40
c. 60
d. 100
b. 40
The PRF is __ Hz if 30 frames (40 lines each) are displayed per second (single focus).
a. 600
b. 1200
c. 30
d. 40
b. 1200
Imaging involving 10-cm penetration, a single focus, 100 scan lines per frame, and 30 frames per second can be accomplished without range ambiguity. T or F?
True (10 x 1 x 100 x 30 = 30,000 <77,000)
The maximum frame rate permitted for 15 cm penetration, 3 foci, and 200 scan lines per frame is ______.
a. 3.0
b. 5.5
c. 8.5
d. 15
e. 30
c. 8.5
A _______ formats scan line data to image form.
a. beam former
b. scan convertor
c. signal processor
d. image formatter
b. scan convertor
Which of the following is not performed by a signal processor?
a. detection
b. filtering
c. digital-to-analog conversion
d. radio frequency-to-amplitude conversion
e. compression
c. digital-to-analog conversion
In a digital memory, echo intensity is represented by _______.
a. positive charge distribution
b. a number stored in the memory
c. electron density of the display writing beam
d. a and c
e. all of the above
b. a number stored in the memory
If there were no attenuation in tissue, ______ would not be needed.
a. filtering
b. compression
c. detection
d. TGC
d. TGC
Echo imaging include ultrasound generation, propagation and reflection in tissues, and reception of returning _____.
a. echoes
b. impedances
c. propagations
d. transmissions
a. echoes
The diagnostic ultrasound systems in common clinical use today are the _______-_____ type.
a. transmit-receive
b. pulse-echo
c. through-transmission
d. A-mode
b. pulse-echo
Gray-scale instruments show echo amplitude as ______ on the display.
a. numbers
b. color
c. spikes
d. brightness
d. brightness
Pulse-echo instruments look for three things: the ______, ______ and arrival _____ of echoes returning from the tissues.
a. amplitude, frequency, location
b. strength, direction, time
c. focus, delay, direction
d. frequency, duration, delay
b. strength, direction, time
An image memory stores image information in the form of ____ numbers.
a. electric charge
b. binary
c. decimal
d. impedance
e. none of the above
b. binary
Imaging systems produce a visual _____ from the electric _____ received from the transducer.
a. display, voltages
b. map, numbers
c. presentation, amplifiers
d. display, numbers
a. display, voltages
The transducer is connected to the signal processor through the ____ _____.
a. pulser delay
b. image processor
c. scan convertor
d. beam former
d. beam former
The ______ receives digitized echo voltages from the beam former.
a. signal processor
b. image processor
c. scan convertor
d. beam former
a. signal processor
Increasing gain generally produces the same effect as ______.
a. decreasing attenuation
b. increasing attenuation
c. increasing compression
d. increasing rectification
e. b and c
a. decreasing attenuation
The ADC is part of the ________.
a. beam former
b. signal processor
c. image processor
d. display
e. a and b
f. c and e
a. beam former
Voltage pulses from the pulser are applied through delays to the _____.
a. digitizer
b. transducer
c. ADCs
d. preprocessor
b. transducer
Detection is a function of the _______.
a. beam former
b. signal processor
c. image processor
d. display
e. a and b
b. signal processor
If gain is reduced by one half, with input power unchanged, the output power is _____ what it was before.
a. equal to
b. twice
c. one-half
d. none of the above
c. one-half
If gain is 30 dB and output power is reduced by one-half, the new gain is ___ dB.
a. 15
b. 60
c. 33
d. 27
e. none of the above
d. 27
If four shades of gray are shown on a display, each twice the brightness of the preceding one, the brightest shade is _____ times the brightness of the dimmest shade.
a. 2
b. 4
c. 8
d. 16
e. 32
c. 8
In which units are gain and attenuation usually expressed?
a. dB
b. dB/cm
c. cm
d. cm/3 dB
e. none of the above
a. dB
Time gain compensation makes up for the face that reflections from deeper reflectors arrive at the transducer with greater amplitude. T or F?
False
A real-time B mode display may be produced by rapid ______ scanning of a transducer array.
a. electronic
b. manual
c. visual
d. reverse
a. electronic
Each complete scan of the sound beam produces an image on the display that is called a ______.
a. picture
b. frame
c. window
d. movie
b. frame
For a single focus, the number of lines in each frame is equal to the number of times the transducer is ______ while the frame is produced; that is, while the sound beam is scanned.
a. quiet
b. focused
c. pulsed
d. delayed
c. pulsed
In real time scanning, the required PRF depends on the number of _______ per frame and ______ rate.
a. lines, frame
b. scans, scan
c. echoes, pulsing
d. focuses, propagation
a. lines, frame
Increasing the number of foci reduces ____ ______.
a. detail resolution
b. contrast resolution
c. pulse repetition
d. frame rate
d. frame rate
To correct for attenuation, TGC must _____ the gain for increasing depth.
a. increase
b. decrease
c. correct
d. decelerate
a. increase
If a higher frequency is used, resolution is ____, imaging depth _______, and the TGC slope must be _____.
a. improved, decreases, increased
b. degraded, increases, decreased
c. unchanged, increases, eliminated
d. improved, increased, increased
a. improved, decreases, increased
For pixel dimensions 256 x 512 and 512 x 512, calculate the number of image pixels.
a. 131,072; 262,144
b. 262,144; 524,288
c. 131,072; 524,288
d. 524,288; 262,144
a. 131,072; 262,144
In elastography, the display presents qualitative or quantitative information on:
a. stress
b. stiffness
c. strain rate
d. stress rate
b. stiffness
Compression is a function of the _____.
a. beam former
b. signal processor
c. image processor
d. postprocessor
b. signal processor
