1. A sonographer notices that increasing the output power significantly improves visualization of
deep structures but also increases patient heating concerns. Which ALARA principle is most
directly relevant here?
A) Use the highest possible frequency to reduce heating
B) Keep mechanical index above 1.5 for safety
C) Minimize output power while maintaining diagnostic image quality
D) Always maximize frame rate to reduce exposure time
Rationale: ALARA requires keeping exposure as low as reasonably achievable; thus output
power should be minimized yet sufficient for diagnosis.
2. During a liver exam, the sonographer switches from a 2 MHz to a 4 MHz transducer. What is
the expected trade-off?
A) Better penetration but worse resolution
B) Improved axial resolution but reduced penetration depth
C) No change in resolution or penetration
D) Increased lateral resolution and deeper imaging
Rationale: Higher frequency improves resolution but increases attenuation, reducing penetration
depth in soft tissue.
3. A pulsed wave Doppler tracing shows aliasing despite a high PRF. The sonographer increases
the Nyquist limit by adjusting which parameter?
A) Increasing the pulse repetition frequency
B) Decreasing the sample volume depth
,C) Reducing the Doppler angle
D) Lowering the transducer frequency
*Rationale: Nyquist limit equals PRF/2; increasing PRF raises the maximum detectable Doppler
shift without aliasing.*
4. While scanning a breast cyst, you see posterior enhancement. What is the most likely cause?
A) High attenuation within the cyst
B) Low attenuation within the cyst compared to surrounding tissue
C) Refraction at the cyst wall
D) Side lobe interference
Rationale: Fluid-filled cysts attenuate sound less than solid tissue, leading to increased echoes
deep to the cyst.
5. A linear array transducer shows a dark vertical band extending from the skin line to depth. The
rest of the image is normal. What is the most likely cause?
A) Improper TGC settings
B) One or more defective transducer elements
C) Incorrect focal zone placement
D) Air bubbles in the coupling gel
Rationale: Dead or damaged elements produce a vertical dropout artifact because no ultrasound
is transmitted/received from that portion of the array.
6. You are performing spectral Doppler on a carotid artery. The angle correction cursor is set to
60 degrees. If you accidentally change it to 0 degrees without changing the transducer position,
what happens to the calculated velocity?
A) Velocity will be falsely lower
,B) Velocity will be falsely higher
C) Velocity remains unchanged
D) Aliasing will disappear
*Rationale: Doppler equation includes cosθ; at 0°, cosθ=1 (true velocity), at 60°, cosθ=0.5, so
uncorrected velocity reading would double if angle set incorrectly.*
7. In an unfocused circular transducer, where is the beam intensity highest?
A) At the transducer face
B) At the end of the near field
C) In the far field
D) Uniform throughout
Rationale: Constructive interference at the Fresnel zone’s end (near zone length) creates a
maximum intensity before divergence.
8. Reverberation artifact appears as multiple equally spaced lines parallel to the beam axis. This
is most commonly caused by:
A) Two parallel strong reflectors
B) Single small calcification
C) Lateral resolution failure
D) Propagation speed error
Rationale: Sound bouncing between two highly reflective interfaces (e.g., transducer face and a
strong reflector) creates repeating echoes.
9. The sonographer increases line density without changing depth or sector width. What is the
direct consequence on frame rate?
A) Frame rate increases
, B) Frame rate decreases
C) Frame rate unchanged
D) Temporal resolution improves
Rationale: More scan lines per frame require more pulses per frame, lowering frames per second
if PRF is fixed.
10. During a gallbladder exam, a patient’s bowel gas creates a dirty shadow. Which physical
process explains this artifact?
A) Specular reflection
B) Strong reflection and scattering at gas-tissue interface
C) Acoustic enhancement
D) Side lobe artifact
Rationale: Gas causes nearly complete reflection and strong scattering, but residual sound
penetration produces a “dirty” rather than clean shadow.
11. You increase the pulse duration of a system. What happens to axial resolution?
A) Axial resolution worsens
B) Axial resolution improves
C) Lateral resolution improves
D) No change in resolution
Rationale: Longer pulse duration increases spatial pulse length, directly degrading axial
resolution (ability to separate structures along beam axis).
12. A continuous wave Doppler transducer has two crystals. What is the purpose of the second
crystal?
A) To improve lateral resolution
deep structures but also increases patient heating concerns. Which ALARA principle is most
directly relevant here?
A) Use the highest possible frequency to reduce heating
B) Keep mechanical index above 1.5 for safety
C) Minimize output power while maintaining diagnostic image quality
D) Always maximize frame rate to reduce exposure time
Rationale: ALARA requires keeping exposure as low as reasonably achievable; thus output
power should be minimized yet sufficient for diagnosis.
2. During a liver exam, the sonographer switches from a 2 MHz to a 4 MHz transducer. What is
the expected trade-off?
A) Better penetration but worse resolution
B) Improved axial resolution but reduced penetration depth
C) No change in resolution or penetration
D) Increased lateral resolution and deeper imaging
Rationale: Higher frequency improves resolution but increases attenuation, reducing penetration
depth in soft tissue.
3. A pulsed wave Doppler tracing shows aliasing despite a high PRF. The sonographer increases
the Nyquist limit by adjusting which parameter?
A) Increasing the pulse repetition frequency
B) Decreasing the sample volume depth
,C) Reducing the Doppler angle
D) Lowering the transducer frequency
*Rationale: Nyquist limit equals PRF/2; increasing PRF raises the maximum detectable Doppler
shift without aliasing.*
4. While scanning a breast cyst, you see posterior enhancement. What is the most likely cause?
A) High attenuation within the cyst
B) Low attenuation within the cyst compared to surrounding tissue
C) Refraction at the cyst wall
D) Side lobe interference
Rationale: Fluid-filled cysts attenuate sound less than solid tissue, leading to increased echoes
deep to the cyst.
5. A linear array transducer shows a dark vertical band extending from the skin line to depth. The
rest of the image is normal. What is the most likely cause?
A) Improper TGC settings
B) One or more defective transducer elements
C) Incorrect focal zone placement
D) Air bubbles in the coupling gel
Rationale: Dead or damaged elements produce a vertical dropout artifact because no ultrasound
is transmitted/received from that portion of the array.
6. You are performing spectral Doppler on a carotid artery. The angle correction cursor is set to
60 degrees. If you accidentally change it to 0 degrees without changing the transducer position,
what happens to the calculated velocity?
A) Velocity will be falsely lower
,B) Velocity will be falsely higher
C) Velocity remains unchanged
D) Aliasing will disappear
*Rationale: Doppler equation includes cosθ; at 0°, cosθ=1 (true velocity), at 60°, cosθ=0.5, so
uncorrected velocity reading would double if angle set incorrectly.*
7. In an unfocused circular transducer, where is the beam intensity highest?
A) At the transducer face
B) At the end of the near field
C) In the far field
D) Uniform throughout
Rationale: Constructive interference at the Fresnel zone’s end (near zone length) creates a
maximum intensity before divergence.
8. Reverberation artifact appears as multiple equally spaced lines parallel to the beam axis. This
is most commonly caused by:
A) Two parallel strong reflectors
B) Single small calcification
C) Lateral resolution failure
D) Propagation speed error
Rationale: Sound bouncing between two highly reflective interfaces (e.g., transducer face and a
strong reflector) creates repeating echoes.
9. The sonographer increases line density without changing depth or sector width. What is the
direct consequence on frame rate?
A) Frame rate increases
, B) Frame rate decreases
C) Frame rate unchanged
D) Temporal resolution improves
Rationale: More scan lines per frame require more pulses per frame, lowering frames per second
if PRF is fixed.
10. During a gallbladder exam, a patient’s bowel gas creates a dirty shadow. Which physical
process explains this artifact?
A) Specular reflection
B) Strong reflection and scattering at gas-tissue interface
C) Acoustic enhancement
D) Side lobe artifact
Rationale: Gas causes nearly complete reflection and strong scattering, but residual sound
penetration produces a “dirty” rather than clean shadow.
11. You increase the pulse duration of a system. What happens to axial resolution?
A) Axial resolution worsens
B) Axial resolution improves
C) Lateral resolution improves
D) No change in resolution
Rationale: Longer pulse duration increases spatial pulse length, directly degrading axial
resolution (ability to separate structures along beam axis).
12. A continuous wave Doppler transducer has two crystals. What is the purpose of the second
crystal?
A) To improve lateral resolution
