DAVIES SPI: IV. Pulse-Echo
Instrumentation (30% of ARDMS)
You have increased the output power by 10 dB. The signal intensity has:
A. Doubled
B. Tripled
C. Quadrupled
D. Increased by a factor of 10
E. Increased by a factor of 100 - Correct Answer-D. Increased by a factor of 10
<Increasing a control by 3 dB corresponds to a doubling of the setting. If it is increased
by 10 dB, it has been increased by a factor of 10>
In this illustration, letter A is demonstrating what type of resolution?
A. Axial
B. Lateral
C. Elevational
D. Contrast
E. Temporal - Correct Answer-B. Lateral
What function of the receiver converts electric signals from radiofrequency to video
form?
A. Amplification
B. Compensation
C. Compression
D. Demodulation
E. Rejection - Correct Answer-D. Demodulation
<Demodulation is accomplished by rectification and smoothing (filtering). Demodulation
may also be called amplitude detection or envelope detection>
What is a typical frame rate for B-mode real-time imaging?
A. 1-9 kHz
B. 10-50 Hz
C. 100-200 MHz
D. 200-300 Hz
E. 0.05-0.9 Hz - Correct Answer-B. 10-50 Hz
,<Frame rates are displayed in terms of Hz, a unit of frequency equal to one cycle per
second. Although frame rates vary, typical real-time frame rates range from 10 Hz to 50
Hz. If the frame rate is 30 Hz, that means 30 frames are produced in one second.
Faster frame rates are found with cardiac imaging>
What component is necessary for a real-time B-mode scanner but is not present in A-
mode scanner?
A. Clock
B. Transmitter
C. Transducer
D. Scan converter
E. Receiver - Correct Answer-D. Scan converter
The range equation describes the relationship between:
A. Acoustic impedance of two media
B. Side-lobe intensity between two crystals
C. Round-trip pulse travel time and distance to the reflector
D. Bandwidth and transducer frequency
E. All of the above - Correct Answer-C. Round-trip pulse travel time and distance to the
reflector
The ratio of the largest to the smallest signal that a system can handle is termed:
A. Apodization
B. Compression
C. Threshold
D. Dynamic range
E. Pulse repetition frequency - Correct Answer-D. Dynamic range
What artifact will you see in the color Doppler image if you cannot increase the PRF to a
level greater than 2 times than that of the Doppler frequency shift?
A. Range ambiguity
B. Overestimation of the flow velocity
C. Overestimation of the Doppler frequency shift
D. Aliasing
E. All of the above - Correct Answer-D. Aliasing
<The Doppler PRF sets the Nyquist limit. Aliasing occurs when the frequency shift
exceeds half the system pulse repetition frequency shift exceeds half the system pulse
repetition frequency (PRF)>
,What physical concept allows us to determine the location of an interface by measuring
the elapsed time between the transmitted pulsed ultrasound wave and the detected
echo from that interface?
A. Huygen's principle
B. Echo ranging
C. Snell's law
D. Doppler effect
E. None of the above - Correct Answer-B. Echo ranging
<Echo ranging involved use of the range equation with pulsed-wave imaging to
determine reflector depth>
Which term below most correctly describes this Doppler waveform?
A. Aliasing
B. Spectral mirroring
C. Spectral broadening due to sample volume size
D. Reverberation
E. Bidirectional flow - Correct Answer-B. Spectral mirroring
You have decreased the scan line density. What technique will be employed to fill in the
empt data between the scan lines?
A. Interpolation
B. Rejection
C. Compression
D. Autocorrelation
E. Demodulation - Correct Answer-A. Interpolation
<Interpolation is used to fill in the missing data between scan lines in both gray-scale
and color Doppler. The missing data are estimated from the data present in nearby
pixels on adjacent scan lines>
Which of the following ultrasound examinations would require the highest frame rate?
A. Small parts
B. Abdominal
C. Pelvic
D. Vascular
E. Cardiac - Correct Answer-E. Cardiac
<Since the heart is a rapidly moving structure, high frame rates are required to assess it
accurately>
, What term is used to describe the three-dimensional pixel element in 3D sonography?
A. Volume point
B. Voxel
C. Quadrant
D. Channel
E. All of the above - Correct Answer-B. Voxel
<The term voxel is used to describe the smallest element of a three-dimensional
volume. It is analogous to the term pixel in 2D imaging>
What system component is responsible for transmit focusing?
A. Receiver
B. Monitor
C. Beam former
D. Preprocessing
E. System clock - Correct Answer-C. Beam former
<Specifically, the transmit beam former, which introduces time delays into the excitation
pulse sequence applied to the elements>
A-mode display is most commonly used for what type of ultrasound imaging?
A. Small parts
B. Abdominal
C. Cardiac
D. Vascular
E. Ophthalmologic - Correct Answer-E. Ophthalmologic
What type of imaging results in selective reception of frequencies that are two times that
of the transmitted frequency?
A. Color Doppler imaging
B. Pulsed Doppler imaging
C. Tissue Doppler imaging
D. M-mode imaging
E. Tissue harmonic imaging - Correct Answer-E. Tissue harmonic imaging
<In tissue harmonic imaging, the receiver selectively "listens" to the harmonic
frequencies that are generated as the sound travels through the tissue. The second
harmonic is the strongest harmonic produced. This is twice the transmitted frequency>
Instrumentation (30% of ARDMS)
You have increased the output power by 10 dB. The signal intensity has:
A. Doubled
B. Tripled
C. Quadrupled
D. Increased by a factor of 10
E. Increased by a factor of 100 - Correct Answer-D. Increased by a factor of 10
<Increasing a control by 3 dB corresponds to a doubling of the setting. If it is increased
by 10 dB, it has been increased by a factor of 10>
In this illustration, letter A is demonstrating what type of resolution?
A. Axial
B. Lateral
C. Elevational
D. Contrast
E. Temporal - Correct Answer-B. Lateral
What function of the receiver converts electric signals from radiofrequency to video
form?
A. Amplification
B. Compensation
C. Compression
D. Demodulation
E. Rejection - Correct Answer-D. Demodulation
<Demodulation is accomplished by rectification and smoothing (filtering). Demodulation
may also be called amplitude detection or envelope detection>
What is a typical frame rate for B-mode real-time imaging?
A. 1-9 kHz
B. 10-50 Hz
C. 100-200 MHz
D. 200-300 Hz
E. 0.05-0.9 Hz - Correct Answer-B. 10-50 Hz
,<Frame rates are displayed in terms of Hz, a unit of frequency equal to one cycle per
second. Although frame rates vary, typical real-time frame rates range from 10 Hz to 50
Hz. If the frame rate is 30 Hz, that means 30 frames are produced in one second.
Faster frame rates are found with cardiac imaging>
What component is necessary for a real-time B-mode scanner but is not present in A-
mode scanner?
A. Clock
B. Transmitter
C. Transducer
D. Scan converter
E. Receiver - Correct Answer-D. Scan converter
The range equation describes the relationship between:
A. Acoustic impedance of two media
B. Side-lobe intensity between two crystals
C. Round-trip pulse travel time and distance to the reflector
D. Bandwidth and transducer frequency
E. All of the above - Correct Answer-C. Round-trip pulse travel time and distance to the
reflector
The ratio of the largest to the smallest signal that a system can handle is termed:
A. Apodization
B. Compression
C. Threshold
D. Dynamic range
E. Pulse repetition frequency - Correct Answer-D. Dynamic range
What artifact will you see in the color Doppler image if you cannot increase the PRF to a
level greater than 2 times than that of the Doppler frequency shift?
A. Range ambiguity
B. Overestimation of the flow velocity
C. Overestimation of the Doppler frequency shift
D. Aliasing
E. All of the above - Correct Answer-D. Aliasing
<The Doppler PRF sets the Nyquist limit. Aliasing occurs when the frequency shift
exceeds half the system pulse repetition frequency shift exceeds half the system pulse
repetition frequency (PRF)>
,What physical concept allows us to determine the location of an interface by measuring
the elapsed time between the transmitted pulsed ultrasound wave and the detected
echo from that interface?
A. Huygen's principle
B. Echo ranging
C. Snell's law
D. Doppler effect
E. None of the above - Correct Answer-B. Echo ranging
<Echo ranging involved use of the range equation with pulsed-wave imaging to
determine reflector depth>
Which term below most correctly describes this Doppler waveform?
A. Aliasing
B. Spectral mirroring
C. Spectral broadening due to sample volume size
D. Reverberation
E. Bidirectional flow - Correct Answer-B. Spectral mirroring
You have decreased the scan line density. What technique will be employed to fill in the
empt data between the scan lines?
A. Interpolation
B. Rejection
C. Compression
D. Autocorrelation
E. Demodulation - Correct Answer-A. Interpolation
<Interpolation is used to fill in the missing data between scan lines in both gray-scale
and color Doppler. The missing data are estimated from the data present in nearby
pixels on adjacent scan lines>
Which of the following ultrasound examinations would require the highest frame rate?
A. Small parts
B. Abdominal
C. Pelvic
D. Vascular
E. Cardiac - Correct Answer-E. Cardiac
<Since the heart is a rapidly moving structure, high frame rates are required to assess it
accurately>
, What term is used to describe the three-dimensional pixel element in 3D sonography?
A. Volume point
B. Voxel
C. Quadrant
D. Channel
E. All of the above - Correct Answer-B. Voxel
<The term voxel is used to describe the smallest element of a three-dimensional
volume. It is analogous to the term pixel in 2D imaging>
What system component is responsible for transmit focusing?
A. Receiver
B. Monitor
C. Beam former
D. Preprocessing
E. System clock - Correct Answer-C. Beam former
<Specifically, the transmit beam former, which introduces time delays into the excitation
pulse sequence applied to the elements>
A-mode display is most commonly used for what type of ultrasound imaging?
A. Small parts
B. Abdominal
C. Cardiac
D. Vascular
E. Ophthalmologic - Correct Answer-E. Ophthalmologic
What type of imaging results in selective reception of frequencies that are two times that
of the transmitted frequency?
A. Color Doppler imaging
B. Pulsed Doppler imaging
C. Tissue Doppler imaging
D. M-mode imaging
E. Tissue harmonic imaging - Correct Answer-E. Tissue harmonic imaging
<In tissue harmonic imaging, the receiver selectively "listens" to the harmonic
frequencies that are generated as the sound travels through the tissue. The second
harmonic is the strongest harmonic produced. This is twice the transmitted frequency>
