ARDMS SPI (Sonography Principles and
Instrumentation) Comprehensive Exam 2025 –
Questions and Correct Answers and Detailed Rationales
1. What is the most common cause of attenuation in soft tissue?
A. Absorption
B. Reflection
C. Scattering
D. Refraction
Correct Answer: A. Absorption
Rationale: Absorption is the primary mechanism of attenuation in soft tissue,
accounting for the majority of the energy loss. While reflection and scattering
contribute, absorption converts sound energy to heat.
2. Which parameter is determined solely by the source and not affected by the
medium?
A. Wavelength
B. Propagation speed
C. Frequency
D. Pulse duration
,Correct Answer: C. Frequency
Rationale: Frequency is determined by the transducer (the sound source) and
does not change as the wave travels through different media. Propagation speed,
in contrast, is determined by the medium.
3. Increasing the imaging depth will result in which of the following?
A. Increased frame rate
B. Decreased frame rate
C. No change in temporal resolution
D. Decreased pulse duration
Correct Answer: B. Decreased frame rate
Rationale: As imaging depth increases, the system needs more time to receive
echoes from deeper structures, reducing the number of frames per second (frame
rate).
4. What artifact appears as a second copy of a structure, equally spaced from a
strong reflector?
A. Reverberation
B. Shadowing
C. Mirror image
D. Comet tail
, Correct Answer: C. Mirror image
Rationale: Mirror image artifacts occur when sound reflects off a strong reflector
and creates a duplicate structure on the opposite side of the reflector.
5. Which of the following improves axial resolution?
A. Shorter spatial pulse length
B. Lower frequency
C. Wider beam width
D. Higher output power
Correct Answer: A. Shorter spatial pulse length
Rationale: Axial resolution depends on spatial pulse length (SPL); a shorter SPL
provides better ability to distinguish two structures along the beam's axis.
6. What happens to the wavelength as frequency increases?
A. Wavelength increases
B. Wavelength remains constant
C. Wavelength decreases
D. Wavelength equals the period
Correct Answer: C. Wavelength decreases
Rationale: Wavelength and frequency are inversely related in a given medium.
7. What is the primary factor affecting propagation speed in tissue?
Instrumentation) Comprehensive Exam 2025 –
Questions and Correct Answers and Detailed Rationales
1. What is the most common cause of attenuation in soft tissue?
A. Absorption
B. Reflection
C. Scattering
D. Refraction
Correct Answer: A. Absorption
Rationale: Absorption is the primary mechanism of attenuation in soft tissue,
accounting for the majority of the energy loss. While reflection and scattering
contribute, absorption converts sound energy to heat.
2. Which parameter is determined solely by the source and not affected by the
medium?
A. Wavelength
B. Propagation speed
C. Frequency
D. Pulse duration
,Correct Answer: C. Frequency
Rationale: Frequency is determined by the transducer (the sound source) and
does not change as the wave travels through different media. Propagation speed,
in contrast, is determined by the medium.
3. Increasing the imaging depth will result in which of the following?
A. Increased frame rate
B. Decreased frame rate
C. No change in temporal resolution
D. Decreased pulse duration
Correct Answer: B. Decreased frame rate
Rationale: As imaging depth increases, the system needs more time to receive
echoes from deeper structures, reducing the number of frames per second (frame
rate).
4. What artifact appears as a second copy of a structure, equally spaced from a
strong reflector?
A. Reverberation
B. Shadowing
C. Mirror image
D. Comet tail
, Correct Answer: C. Mirror image
Rationale: Mirror image artifacts occur when sound reflects off a strong reflector
and creates a duplicate structure on the opposite side of the reflector.
5. Which of the following improves axial resolution?
A. Shorter spatial pulse length
B. Lower frequency
C. Wider beam width
D. Higher output power
Correct Answer: A. Shorter spatial pulse length
Rationale: Axial resolution depends on spatial pulse length (SPL); a shorter SPL
provides better ability to distinguish two structures along the beam's axis.
6. What happens to the wavelength as frequency increases?
A. Wavelength increases
B. Wavelength remains constant
C. Wavelength decreases
D. Wavelength equals the period
Correct Answer: C. Wavelength decreases
Rationale: Wavelength and frequency are inversely related in a given medium.
7. What is the primary factor affecting propagation speed in tissue?
