ARDMS SPI ACTUAL EXAM – QUESTIONS AND ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS
RATIONALES | DOWNLOAD AND PASS | LATEST EXAM UPDATE 2026/2027
SECTION ONE: QUESTIONS 1-50
1. What is the primary purpose of the ultrasound system's receiver in the imaging chain?
A. To increase the amplitude of the electrical signal for display
B. To convert sound waves into electrical energy
C. To process and condition the electrical signal from the transducer
D. To generate the electrical voltage that excites the transducer elements
Correct Answer: C. To process and condition the electrical signal from the transducer
Rationale: The receiver's main function is to take the weak electrical signals from the transducer and process them
through a series of stages (amplification, compensation, compression, etc.) to create a signal suitable for display.
Option A is only one part of the receiver's function (amplification). Option B describes the piezoelectric effect,
which occurs in the transducer. Option D describes the function of the pulser.
2. Which of the following describes the piezoelectric effect?
A. The conversion of electrical energy into heat
,B. The conversion of sound energy into mechanical energy
C. The conversion of mechanical energy into electrical energy and vice versa
D. The conversion of sound energy into heat
Correct Answer: C. The conversion of mechanical energy into electrical energy and vice versa
Rationale: The piezoelectric effect is the fundamental principle behind ultrasound transducers. It is the ability of
certain materials (like PZT) to generate an electrical voltage when mechanically deformed (receiving) and to
deform when an electrical voltage is applied (transmitting). Options A, B, and D describe other forms of energy
conversion but not the specific reversible process of the piezoelectric effect.
3. In ultrasound physics, what is the average speed of sound in soft tissue?
A. 1,540 m/s
B. 1,450 m/s
C. 1,550 m/s
D. 1,600 m/s
Correct Answer: A. 1,540 m/s
Rationale: 1,540 m/s is the standard average speed of sound in soft tissue, a value used by the ultrasound system
for calibration and depth calculations. While 1,450 m/s is close, 1,540 m/s is the accepted standard. 1,550 m/s and
,1,600 m/s are not the recognized average for soft tissue.
4. A sonographer adjusts the output power. Which of the following bioeffects is of primary concern?
A. Acoustic streaming
B. Radiation force
C. Thermal effects
D. Cavitation
Correct Answer: C. Thermal effects
Rationale: Increasing output power directly increases the acoustic energy deposited in the tissue, leading to a rise
in temperature, or thermal effects. While cavitation (D) and other mechanical effects (A and B) are bioeffects,
thermal effects are the most direct and primary concern when increasing output power.
5. Which acoustic parameter is defined as the number of cycles an acoustic wave completes in one second?
A. Period
B. Wavelength
C. Frequency
, D. Amplitude
Correct Answer: C. Frequency
Rationale: Frequency is the number of cycles per second, measured in Hertz (Hz). Period (A) is the time for one
cycle, wavelength (B) is the length of one cycle, and amplitude (D) is the maximum variation of an acoustic
variable.
6. A sonographer is imaging a structure at a depth of 8 cm. What is the round-trip travel time for the sound
pulse?
A. 52 microseconds
B. 104 microseconds
C. 52 milliseconds
D. 104 milliseconds
Correct Answer: B. 104 microseconds
Rationale: Using the 13-microsecond rule for every centimeter of depth in soft tissue, the round-trip time for 8 cm
is 8 cm x 13 µs/cm = 104 µs. 52 microseconds is the time for a one-way trip, and options C and D are incorrect
because the value is in microseconds, not milliseconds.
RATIONALES | DOWNLOAD AND PASS | LATEST EXAM UPDATE 2026/2027
SECTION ONE: QUESTIONS 1-50
1. What is the primary purpose of the ultrasound system's receiver in the imaging chain?
A. To increase the amplitude of the electrical signal for display
B. To convert sound waves into electrical energy
C. To process and condition the electrical signal from the transducer
D. To generate the electrical voltage that excites the transducer elements
Correct Answer: C. To process and condition the electrical signal from the transducer
Rationale: The receiver's main function is to take the weak electrical signals from the transducer and process them
through a series of stages (amplification, compensation, compression, etc.) to create a signal suitable for display.
Option A is only one part of the receiver's function (amplification). Option B describes the piezoelectric effect,
which occurs in the transducer. Option D describes the function of the pulser.
2. Which of the following describes the piezoelectric effect?
A. The conversion of electrical energy into heat
,B. The conversion of sound energy into mechanical energy
C. The conversion of mechanical energy into electrical energy and vice versa
D. The conversion of sound energy into heat
Correct Answer: C. The conversion of mechanical energy into electrical energy and vice versa
Rationale: The piezoelectric effect is the fundamental principle behind ultrasound transducers. It is the ability of
certain materials (like PZT) to generate an electrical voltage when mechanically deformed (receiving) and to
deform when an electrical voltage is applied (transmitting). Options A, B, and D describe other forms of energy
conversion but not the specific reversible process of the piezoelectric effect.
3. In ultrasound physics, what is the average speed of sound in soft tissue?
A. 1,540 m/s
B. 1,450 m/s
C. 1,550 m/s
D. 1,600 m/s
Correct Answer: A. 1,540 m/s
Rationale: 1,540 m/s is the standard average speed of sound in soft tissue, a value used by the ultrasound system
for calibration and depth calculations. While 1,450 m/s is close, 1,540 m/s is the accepted standard. 1,550 m/s and
,1,600 m/s are not the recognized average for soft tissue.
4. A sonographer adjusts the output power. Which of the following bioeffects is of primary concern?
A. Acoustic streaming
B. Radiation force
C. Thermal effects
D. Cavitation
Correct Answer: C. Thermal effects
Rationale: Increasing output power directly increases the acoustic energy deposited in the tissue, leading to a rise
in temperature, or thermal effects. While cavitation (D) and other mechanical effects (A and B) are bioeffects,
thermal effects are the most direct and primary concern when increasing output power.
5. Which acoustic parameter is defined as the number of cycles an acoustic wave completes in one second?
A. Period
B. Wavelength
C. Frequency
, D. Amplitude
Correct Answer: C. Frequency
Rationale: Frequency is the number of cycles per second, measured in Hertz (Hz). Period (A) is the time for one
cycle, wavelength (B) is the length of one cycle, and amplitude (D) is the maximum variation of an acoustic
variable.
6. A sonographer is imaging a structure at a depth of 8 cm. What is the round-trip travel time for the sound
pulse?
A. 52 microseconds
B. 104 microseconds
C. 52 milliseconds
D. 104 milliseconds
Correct Answer: B. 104 microseconds
Rationale: Using the 13-microsecond rule for every centimeter of depth in soft tissue, the round-trip time for 8 cm
is 8 cm x 13 µs/cm = 104 µs. 52 microseconds is the time for a one-way trip, and options C and D are incorrect
because the value is in microseconds, not milliseconds.
