ARDMS SPI Exam Questions and Correct
Answer plus Rationale | Latest 2026-2027 Update
Which gain will increase the risk of bioeffects?
A. transmit
B. receive
C. gain
D. overall gain
Correct Answer: A. transmit
Rationale: Transmit gain increases acoustic output (power/intensity) delivered to
the patient, raising bioeffect risk. Receive gain and overall gain only amplify
returning echoes for display and do not increase patient exposure.
Which of the following is considered the memory of an ultrasound instrument?
A. pulser
B. transducer
C. receiver
D. beam former
E. digital scan converter
F. display monitor
Correct Answer: E. digital scan converter
Rationale: The digital scan converter stores image data in memory before display,
making it the memory component of the ultrasound system.
Spectral broadening suggests:
A. laminar flow
B. turbulent flow
,C. flow away from the transducer
D. flow towards the transducer
Correct Answer: B. turbulent flow
Rationale: Turbulent flow contains many different velocities, widening the
Doppler spectrum and filling in the spectral window.
With pulsed wave Doppler, axial resolution:
Correct Answer: degrades
Rationale: Pulsed wave Doppler uses longer pulses than imaging, which worsens
axial (range) resolution.
What color is usually used in a color flow Doppler variance map to indicate
turbulent flow?
Correct Answer: green
Rationale: By convention, green is added to the color map to indicate
variance/turbulence.
Doppler high pass filter eliminates:
Correct Answer: high amplitude signals; low velocity flow
Rationale: The wall filter (high-pass filter) removes strong, low-velocity signals
from moving vessel walls and surrounding tissue.
The Doppler wall filter is considered a:
Correct Answer: high pass filter
Rationale: It rejects low Doppler frequency shifts (low velocities) and passes
higher frequency shifts from blood flow.
, The Nyquist Limit is equal to:
A. propagation speed × frequency
B. propagation speed / wavelength
C. PRF / 2
D. 4 × V²
Correct Answer: C. PRF / 2
Rationale: Aliasing occurs when the Doppler shift exceeds one-half the pulse
repetition frequency (Nyquist limit).
Multiple echoes, equally spaced originating from a gas bubble is called:
A. comet tail
B. ring down
C. slice thickness artifact
D. multipath
Correct Answer: B. ring down
Rationale: Ring-down artifact appears as a series of equally spaced echoes distal
to a gas bubble or strong reflector.
An increase in red blood cell velocity will _____ the Doppler Shift:
A. increase
B. decrease
C. not change
D. cannot be predicted
Correct Answer: A. increase
Rationale: Doppler shift is directly proportional to blood flow velocity.
The primary advantage of CW Doppler is:
Answer plus Rationale | Latest 2026-2027 Update
Which gain will increase the risk of bioeffects?
A. transmit
B. receive
C. gain
D. overall gain
Correct Answer: A. transmit
Rationale: Transmit gain increases acoustic output (power/intensity) delivered to
the patient, raising bioeffect risk. Receive gain and overall gain only amplify
returning echoes for display and do not increase patient exposure.
Which of the following is considered the memory of an ultrasound instrument?
A. pulser
B. transducer
C. receiver
D. beam former
E. digital scan converter
F. display monitor
Correct Answer: E. digital scan converter
Rationale: The digital scan converter stores image data in memory before display,
making it the memory component of the ultrasound system.
Spectral broadening suggests:
A. laminar flow
B. turbulent flow
,C. flow away from the transducer
D. flow towards the transducer
Correct Answer: B. turbulent flow
Rationale: Turbulent flow contains many different velocities, widening the
Doppler spectrum and filling in the spectral window.
With pulsed wave Doppler, axial resolution:
Correct Answer: degrades
Rationale: Pulsed wave Doppler uses longer pulses than imaging, which worsens
axial (range) resolution.
What color is usually used in a color flow Doppler variance map to indicate
turbulent flow?
Correct Answer: green
Rationale: By convention, green is added to the color map to indicate
variance/turbulence.
Doppler high pass filter eliminates:
Correct Answer: high amplitude signals; low velocity flow
Rationale: The wall filter (high-pass filter) removes strong, low-velocity signals
from moving vessel walls and surrounding tissue.
The Doppler wall filter is considered a:
Correct Answer: high pass filter
Rationale: It rejects low Doppler frequency shifts (low velocities) and passes
higher frequency shifts from blood flow.
, The Nyquist Limit is equal to:
A. propagation speed × frequency
B. propagation speed / wavelength
C. PRF / 2
D. 4 × V²
Correct Answer: C. PRF / 2
Rationale: Aliasing occurs when the Doppler shift exceeds one-half the pulse
repetition frequency (Nyquist limit).
Multiple echoes, equally spaced originating from a gas bubble is called:
A. comet tail
B. ring down
C. slice thickness artifact
D. multipath
Correct Answer: B. ring down
Rationale: Ring-down artifact appears as a series of equally spaced echoes distal
to a gas bubble or strong reflector.
An increase in red blood cell velocity will _____ the Doppler Shift:
A. increase
B. decrease
C. not change
D. cannot be predicted
Correct Answer: A. increase
Rationale: Doppler shift is directly proportional to blood flow velocity.
The primary advantage of CW Doppler is:
