EDELMAN UNDERSTANDING
ULTRASOUND PHYSICS EXAM REVIEW
A maximum Doppler shift is obtained 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 - ANSWERS-180 degrees
True or false? The appearance of negative velocities on the spectral display of a
continuous wave Doppler exam always indicates that red blood cells are moving
away from the transducer. - ANSWERS-True
With regard to CW Doppler, is the following statement true or false? A minimum
of two distinct piezoelectric crystals are in the transducer. - ANSWERS-True
With regard to CW Doppler, is the following statement true or false? Problems
with aliasing significantly limit its clinical utility. - ANSWERS-False
,With regard to CW Doppler, is the following statement true or false? Frequencies
measured at the transducer are produced from many different locations along the
ultrasonic beam. - ANSWERS-True
With regard to CW Doppler, is the following statement true or false? The duty
cycle of the continuous wave is 100%. - ANSWERS-True
All of the following are related to dedicated continuous wave Doppler transducers
except :
a. Wide bandwidth
b. High quality factor
c. Higher sensitivity
d. Range ambiguity - ANSWERS-Wide bandwidth
A duplex ultrasound system displays _________ information.
a. M-mode, two-dimensional image, and A-mode
b. A-mode and B-mode
c. Two-dimensional image and Doppler
d. Two-dimensional image and M-mode - ANSWERS-Two-dimensional image and
Doppler
All of the following are associated with a CW Doppler transducer except :
a. Narrow bandwidth
,b. Increased sensitivity
c. Backing material
d. High Q-factor - ANSWERS-Backing material
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 - ANSWERS-Attenuation
True or false? The appearance of negative velocities in a pulsed Doppler display
always indicates that red blood cells are moving away from the transducer. -
ANSWERS-False
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 - ANSWERS-Aliasing
, The highest doppler frequency without the appearance of aliasing is called the
______ and is equal to ______.
a. Aliasing limit, half of the emitted frequency
b. Pulse repetition frequency, the pulse repetition frequency
c. Nyquist limit, half of the emitted frequency
d. Nyquist limit, half of the emitted PRF - ANSWERS-Nyquist limit, half of the
emitted PRF
True or false? In a pulsed Doppler exam,the use of a higher transducer frequency
increases the likelihood that aliasing will appear. - ANSWERS-True
True or false? The higher the pulse repetition frequency of a Doppler exam, the
more likely aliasing is to occur. - ANSWERS-False
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 -
ANSWERS-Use the 3.25 MHz transducer
The frequency of a pulsed Doppler wave is 6 MHz, and the PRF is 5 kHz. What is
the maximum Doppler shift that can be recorded without aliasing?
ULTRASOUND PHYSICS EXAM REVIEW
A maximum Doppler shift is obtained 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 - ANSWERS-180 degrees
True or false? The appearance of negative velocities on the spectral display of a
continuous wave Doppler exam always indicates that red blood cells are moving
away from the transducer. - ANSWERS-True
With regard to CW Doppler, is the following statement true or false? A minimum
of two distinct piezoelectric crystals are in the transducer. - ANSWERS-True
With regard to CW Doppler, is the following statement true or false? Problems
with aliasing significantly limit its clinical utility. - ANSWERS-False
,With regard to CW Doppler, is the following statement true or false? Frequencies
measured at the transducer are produced from many different locations along the
ultrasonic beam. - ANSWERS-True
With regard to CW Doppler, is the following statement true or false? The duty
cycle of the continuous wave is 100%. - ANSWERS-True
All of the following are related to dedicated continuous wave Doppler transducers
except :
a. Wide bandwidth
b. High quality factor
c. Higher sensitivity
d. Range ambiguity - ANSWERS-Wide bandwidth
A duplex ultrasound system displays _________ information.
a. M-mode, two-dimensional image, and A-mode
b. A-mode and B-mode
c. Two-dimensional image and Doppler
d. Two-dimensional image and M-mode - ANSWERS-Two-dimensional image and
Doppler
All of the following are associated with a CW Doppler transducer except :
a. Narrow bandwidth
,b. Increased sensitivity
c. Backing material
d. High Q-factor - ANSWERS-Backing material
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 - ANSWERS-Attenuation
True or false? The appearance of negative velocities in a pulsed Doppler display
always indicates that red blood cells are moving away from the transducer. -
ANSWERS-False
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 - ANSWERS-Aliasing
, The highest doppler frequency without the appearance of aliasing is called the
______ and is equal to ______.
a. Aliasing limit, half of the emitted frequency
b. Pulse repetition frequency, the pulse repetition frequency
c. Nyquist limit, half of the emitted frequency
d. Nyquist limit, half of the emitted PRF - ANSWERS-Nyquist limit, half of the
emitted PRF
True or false? In a pulsed Doppler exam,the use of a higher transducer frequency
increases the likelihood that aliasing will appear. - ANSWERS-True
True or false? The higher the pulse repetition frequency of a Doppler exam, the
more likely aliasing is to occur. - ANSWERS-False
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 -
ANSWERS-Use the 3.25 MHz transducer
The frequency of a pulsed Doppler wave is 6 MHz, and the PRF is 5 kHz. What is
the maximum Doppler shift that can be recorded without aliasing?
