ARDMS SPI Ultrasound System Controls and Knobology 1 — Questions and Answers
Question 1: Which control adjusts the amplification of returning ultrasound signals uniformly across all depths?
- Overall gain (Correct answer)
- Time gain compensation
- Dynamic range
- Wall filter
Correct answer: Overall gain
Overall gain amplifies all returning signals equally regardless of depth.
Question 2: Time gain compensation (TGC) is used to correct for which phenomenon?
- Aliasing
- Reverberation
- Attenuation with depth (Correct answer)
- Side lobe artifact
Correct answer: Attenuation with depth
TGC applies increasing amplification to deeper echoes to compensate for attenuation as sound travels through tissue.
Question 3: Increasing the depth setting on an ultrasound system will have what effect on frame rate?
- Frame rate increases
- Frame rate decreases (Correct answer)
- Frame rate is unaffected
- Frame rate doubles
Correct answer: Frame rate decreases
Increasing depth requires longer pulse travel time, reducing the number of frames that can be acquired per second.
Question 4: The pulse repetition frequency (PRF) setting directly affects which Doppler parameter?
- Beam steering angle
- Maximum detectable velocity (Nyquist limit) (Correct answer)
- Spectral baseline position only
- Wall filter cutoff
Correct answer: Maximum detectable velocity (Nyquist limit)
The Nyquist limit is equal to PRF/2, so increasing PRF raises the maximum velocity that can be displayed without aliasing.
Question 5: What does the wall filter (high-pass filter) in Doppler mode eliminate?
- High-frequency signals from fast blood flow
- Low-frequency signals from slow-moving vessel walls (Correct answer)
- Side lobe signals from adjacent structures
- Mirror image artifacts
Correct answer: Low-frequency signals from slow-moving vessel walls
The wall filter removes low-frequency, high-amplitude signals generated by slow-moving vessel walls and surrounding tissue.
Question 6: Which control is adjusted to change the size of the color Doppler sample box?
- PRF
- Color gain
- Color box size/region of interest (Correct answer)
- Ensemble length
Correct answer: Color box size/region of interest
The color box size or region of interest control determines the area over which color Doppler information is displayed, directly affecting frame rate.
ARDMS SPI Ultrasound System Controls and Knobology 1
Which control adjusts the amplification of returning ultrasound signals uniformly across all depths?