UTC Ultrasound Technologist Equipment Operation 3 — Questions and Answers
Question 1: Which mode of ultrasound displays a graph of echo amplitude versus time along a single line of sight?
- B-mode
- M-mode
- A-mode (Correct answer)
- Doppler mode
Correct answer: A-mode
A-mode (amplitude mode) displays echo strength as vertical spikes along a horizontal time axis, representing a single scan line.
Question 2: M-mode (motion mode) ultrasound is particularly useful for evaluating:
- Fetal biometry in the third trimester
- Cardiac valve motion and wall movement (Correct answer)
- Deep abdominal organ texture
- Superficial lymph node size
Correct answer: Cardiac valve motion and wall movement
M-mode records motion of structures along a single scan line over time, making it ideal for assessing cardiac valve motion and chamber wall excursion.
Question 3: What transducer characteristic most directly determines axial resolution?
- Transducer diameter
- Pulse spatial length (pulse duration × propagation speed) (Correct answer)
- Beam width at the focus
- Aperture size
Correct answer: Pulse spatial length (pulse duration × propagation speed)
Axial resolution equals half the spatial pulse length; shorter pulses (higher frequency, fewer cycles) produce better axial resolution.
Question 4: A sonographer notices 'acoustic enhancement' (posterior enhancement) posterior to a structure. This indicates the structure is most likely:
- Solid with high attenuation
- Calcified or fibrotic
- Fluid-filled with low attenuation (Correct answer)
- Highly vascular
Correct answer: Fluid-filled with low attenuation
Fluid-filled structures attenuate sound less than surrounding tissue, so the region posterior to them appears brighter — a phenomenon called posterior acoustic enhancement.
Question 5: Which Doppler technique allows simultaneous 2D imaging and pulsed Doppler sampling from a specific depth?
- Continuous-wave Doppler
- Color flow Doppler
- Duplex Doppler (Correct answer)
- Power Doppler
Correct answer: Duplex Doppler
Duplex Doppler combines real-time B-mode imaging with pulsed-wave Doppler, allowing precise placement of the sample gate at a specific anatomical location.
Question 6: When using color flow Doppler, the color assigned to flow toward the transducer is conventionally:
- Blue
- Green
- Red (Correct answer)
- Yellow
Correct answer: Red
By BART convention (Blue Away, Red Toward), flow toward the transducer is displayed in red and flow away is displayed in blue.
Question 7: What is the effect of increasing ultrasound frequency on tissue penetration and resolution?
- Increases penetration and worsens resolution
- Decreases penetration and improves resolution (Correct answer)
- Increases both penetration and resolution
- Decreases both penetration and resolution
Correct answer: Decreases penetration and improves resolution
Higher frequency ultrasound is attenuated more rapidly (less penetration) but produces shorter wavelengths that improve spatial resolution.
UTC Ultrasound Technologist Equipment Operation 3
Which mode of ultrasound displays a graph of echo amplitude versus time along a single line of sight?