ARDMS SPI EXAM
COMPREHENSIVE PRACTICE (2026/2027 EDITION)
150 Multiple-Choice Questions - Complete Practice Exam
Independent-Study Disclaimer
This practice examination is an independent study aid and is not affiliated with, endorsed by, or sponsored by the
American Registry for Diagnostic Medical Sonography (ARDMS) or any other testing organization. It is provided
for educational and self-assessment purposes only and is not a substitute for official ARDMS SPI study materials
or sonography professional guidance. Exam content, blueprints, and safety standards are subject to change;
always consult current ARDMS and regulatory resources.
, Section 1: Ultrasound Physics – Sound Wave Properties, Propagation, and
Attenuation (25 questions)
Q1: What is the average speed of sound in soft tissue?
A. 330 m/s
B. 3,000 m/s
C. 154 m/s
D. 1,540 m/s [CORRECT]
Correct Answer: D
Rationale: The average speed of sound in soft tissue is approximately 1,540 m/s. 330 m/s is air, and the
other values are incorrect.
Q2: Frequency and wavelength in ultrasound are related such that, as frequency increases, wavelength:
A. Increases
B. Stays the same
C. Decreases [CORRECT]
D. Is unrelated
Correct Answer: C
Rationale: Wavelength is inversely related to frequency (wavelength = speed/frequency); higher frequency
produces shorter wavelength.
Q3: The period of a sound wave is determined by the:
A. Medium through which it travels
B. Sound source (transducer) [CORRECT]
C. Receiver
D. Damping material
Correct Answer: B
Rationale: The period is a property of the sound source; it is set by the transducer and does not change as
the wave travels.
Q4: Which of the following describes the maximum variation of a sound wave's pressure?
A. Frequency
B. Amplitude [CORRECT]
C. Period
D. Propagation speed
Correct Answer: B
Rationale: Amplitude is the maximum variation in pressure (or intensity) of the wave. Frequency, period, and
speed describe other properties.
ARDMS SPI Exam Practice - 2026/2027 Edition Page 2
, Q5: Attenuation of ultrasound in tissue is caused by:
A. Absorption, reflection, and scattering [CORRECT]
B. Only reflection
C. Only absorption
D. Reinforcement only
Correct Answer: A
Rationale: Attenuation results from absorption, reflection, and scattering of the beam as it travels. It is not a
single mechanism.
Q6: The attenuation coefficient in soft tissue is proportional to:
A. Wavelength
B. Frequency [CORRECT]
C. Period
D. Amplitude only
Correct Answer: B
Rationale: The attenuation coefficient increases with frequency (about 0.5 dB/cm/MHz in soft tissue).
Wavelength, period, and amplitude do not determine the coefficient.
Q7: Which physical principle states that the degree of reflection at an interface depends on the difference in
acoustic impedance?
A. Reflection coefficient related to acoustic impedance mismatch [CORRECT]
B. Poiseuille's law
C. Bernoulli principle
D. Reynolds number
Correct Answer: A
Rationale: The reflection coefficient depends on the acoustic impedance mismatch between two media.
Poiseuille, Bernoulli, and Reynolds relate to flow/velocity.
Q8: Refraction occurs when sound:
A. Is absorbed
B. Scatters randomly
C. Is reflected back at 90 degrees
D. Changes direction as it passes obliquely between media of different speeds [CORRECT]
Correct Answer: D
Rationale: Refraction is the change in direction of sound passing obliquely between media with different
propagation speeds. Absorption and scattering are different.
Q9: Acoustic impedance (Z) is calculated as:
A. Density / speed
B. Speed × frequency
C. Density × propagation speed [CORRECT]
D. Wavelength × frequency
Correct Answer: C
Rationale: Acoustic impedance equals tissue density multiplied by propagation speed. The other
expressions are incorrect.
ARDMS SPI Exam Practice - 2026/2027 Edition Page 3
, Q10: Which of the following is most likely to produce strong reflection at an interface?
A. A small difference in impedance
B. Identical impedance
C. A large difference in acoustic impedance [CORRECT]
D. A low frequency
Correct Answer: C
Rationale: Strong reflection occurs when there is a large acoustic impedance mismatch. Small or identical
impedance produces little reflection.
Q11: Which unit is used to express the intensity of an ultrasound beam?
A. W/cm² (watts per square centimeter) [CORRECT]
B. m/s
C. dB
D. Hz
Correct Answer: A
Rationale: Intensity is expressed in watts per square centimeter (W/cm²). m/s is speed, dB is relative ratio,
and Hz is frequency.
Q12: Power is defined as:
A. The rate at which energy is transferred (energy per unit time) [CORRECT]
B. The distance a wave travels
C. The number of cycles per second
D. The height of the wave
Correct Answer: A
Rationale: Power is the rate of energy transfer per unit time. Distance, frequency, and amplitude describe
other quantities.
Q13: Which of the following describes the ability of a medium to be compressed?
A. Attenuation
B. Refraction
C. Compressibility [CORRECT]
D. Damping
Correct Answer: C
Rationale: Compressibility is a property of the medium that, along with density, determines propagation
speed. The others are different.
Q14: Sound waves cannot travel through:
A. Soft tissue
B. Water
C. Bone
D. A vacuum [CORRECT]
Correct Answer: D
Rationale: Sound requires a medium; it cannot travel through a vacuum. It travels through tissue, water, and
bone.
ARDMS SPI Exam Practice - 2026/2027 Edition Page 4
COMPREHENSIVE PRACTICE (2026/2027 EDITION)
150 Multiple-Choice Questions - Complete Practice Exam
Independent-Study Disclaimer
This practice examination is an independent study aid and is not affiliated with, endorsed by, or sponsored by the
American Registry for Diagnostic Medical Sonography (ARDMS) or any other testing organization. It is provided
for educational and self-assessment purposes only and is not a substitute for official ARDMS SPI study materials
or sonography professional guidance. Exam content, blueprints, and safety standards are subject to change;
always consult current ARDMS and regulatory resources.
, Section 1: Ultrasound Physics – Sound Wave Properties, Propagation, and
Attenuation (25 questions)
Q1: What is the average speed of sound in soft tissue?
A. 330 m/s
B. 3,000 m/s
C. 154 m/s
D. 1,540 m/s [CORRECT]
Correct Answer: D
Rationale: The average speed of sound in soft tissue is approximately 1,540 m/s. 330 m/s is air, and the
other values are incorrect.
Q2: Frequency and wavelength in ultrasound are related such that, as frequency increases, wavelength:
A. Increases
B. Stays the same
C. Decreases [CORRECT]
D. Is unrelated
Correct Answer: C
Rationale: Wavelength is inversely related to frequency (wavelength = speed/frequency); higher frequency
produces shorter wavelength.
Q3: The period of a sound wave is determined by the:
A. Medium through which it travels
B. Sound source (transducer) [CORRECT]
C. Receiver
D. Damping material
Correct Answer: B
Rationale: The period is a property of the sound source; it is set by the transducer and does not change as
the wave travels.
Q4: Which of the following describes the maximum variation of a sound wave's pressure?
A. Frequency
B. Amplitude [CORRECT]
C. Period
D. Propagation speed
Correct Answer: B
Rationale: Amplitude is the maximum variation in pressure (or intensity) of the wave. Frequency, period, and
speed describe other properties.
ARDMS SPI Exam Practice - 2026/2027 Edition Page 2
, Q5: Attenuation of ultrasound in tissue is caused by:
A. Absorption, reflection, and scattering [CORRECT]
B. Only reflection
C. Only absorption
D. Reinforcement only
Correct Answer: A
Rationale: Attenuation results from absorption, reflection, and scattering of the beam as it travels. It is not a
single mechanism.
Q6: The attenuation coefficient in soft tissue is proportional to:
A. Wavelength
B. Frequency [CORRECT]
C. Period
D. Amplitude only
Correct Answer: B
Rationale: The attenuation coefficient increases with frequency (about 0.5 dB/cm/MHz in soft tissue).
Wavelength, period, and amplitude do not determine the coefficient.
Q7: Which physical principle states that the degree of reflection at an interface depends on the difference in
acoustic impedance?
A. Reflection coefficient related to acoustic impedance mismatch [CORRECT]
B. Poiseuille's law
C. Bernoulli principle
D. Reynolds number
Correct Answer: A
Rationale: The reflection coefficient depends on the acoustic impedance mismatch between two media.
Poiseuille, Bernoulli, and Reynolds relate to flow/velocity.
Q8: Refraction occurs when sound:
A. Is absorbed
B. Scatters randomly
C. Is reflected back at 90 degrees
D. Changes direction as it passes obliquely between media of different speeds [CORRECT]
Correct Answer: D
Rationale: Refraction is the change in direction of sound passing obliquely between media with different
propagation speeds. Absorption and scattering are different.
Q9: Acoustic impedance (Z) is calculated as:
A. Density / speed
B. Speed × frequency
C. Density × propagation speed [CORRECT]
D. Wavelength × frequency
Correct Answer: C
Rationale: Acoustic impedance equals tissue density multiplied by propagation speed. The other
expressions are incorrect.
ARDMS SPI Exam Practice - 2026/2027 Edition Page 3
, Q10: Which of the following is most likely to produce strong reflection at an interface?
A. A small difference in impedance
B. Identical impedance
C. A large difference in acoustic impedance [CORRECT]
D. A low frequency
Correct Answer: C
Rationale: Strong reflection occurs when there is a large acoustic impedance mismatch. Small or identical
impedance produces little reflection.
Q11: Which unit is used to express the intensity of an ultrasound beam?
A. W/cm² (watts per square centimeter) [CORRECT]
B. m/s
C. dB
D. Hz
Correct Answer: A
Rationale: Intensity is expressed in watts per square centimeter (W/cm²). m/s is speed, dB is relative ratio,
and Hz is frequency.
Q12: Power is defined as:
A. The rate at which energy is transferred (energy per unit time) [CORRECT]
B. The distance a wave travels
C. The number of cycles per second
D. The height of the wave
Correct Answer: A
Rationale: Power is the rate of energy transfer per unit time. Distance, frequency, and amplitude describe
other quantities.
Q13: Which of the following describes the ability of a medium to be compressed?
A. Attenuation
B. Refraction
C. Compressibility [CORRECT]
D. Damping
Correct Answer: C
Rationale: Compressibility is a property of the medium that, along with density, determines propagation
speed. The others are different.
Q14: Sound waves cannot travel through:
A. Soft tissue
B. Water
C. Bone
D. A vacuum [CORRECT]
Correct Answer: D
Rationale: Sound requires a medium; it cannot travel through a vacuum. It travels through tissue, water, and
bone.
ARDMS SPI Exam Practice - 2026/2027 Edition Page 4
