LATEST ARDMS SONOGRAPHY
PRINCIPLES & INSTRUMENTATION (SPI)
EXAM | QUESTIONS WITH ANSWERS AND
RATIONALES
1. What is the primary physical principle of
ultrasound imaging?
A) Reflection of sound waves at tissue interfaces
(acoustic impedance differences)
B) X-ray attenuation
C) Magnetic resonance
D) Gamma ray emission
Correct answer: A
Rationale: Ultrasound relies on reflection (echoes) of
high-frequency sound waves at boundaries of tissues
with different acoustic impedances.
2. What is "acoustic impedance" (Z) in ultrasound?
A) Speed of sound in tissue multiplied by tissue
density (Z = density × sound velocity)
B) Frequency of the transducer
C) Amplitude of the wave
,D) Wavelength of the sound
Correct answer: A
Rationale: Acoustic impedance determines how
much sound is reflected at an interface. The greater
the impedance mismatch, the stronger the echo.
3. Which of the following has the highest acoustic
impedance and appears brightest on ultrasound
(hyperechoic)?
A) Fluid (simple cyst)
B) Bone (very high impedance, strong reflector,
bright with posterior shadowing)
C) Blood
D) Fat
Correct answer: B
Rationale: Bone has very high acoustic impedance
causing almost complete reflection and posterior
acoustic shadowing.
4. Which of the following appears anechoic (black) on
ultrasound and demonstrates posterior acoustic
enhancement (brightness behind)?
A) Simple cyst (fluid)
,B) Bone
C) Calcification
D) Kidney stone
Correct answer: A
Rationale: Simple fluid is anechoic and allows sound
to pass through, causing increased through-
transmission (posterior enhancement).
5. What is the normal range of sound velocities in soft
tissue used for ultrasound calibration?
A) 100 m/s
B) 1540 m/s (approximately 1540-1580 m/s for most
soft tissue)
C) 340 m/s (speed in air)
D) 5000 m/s (speed in bone)
Correct answer: B
Rationale: Ultrasound machines are calibrated to an
average soft tissue speed of 1540 m/s (1.54 mm/μs).
6. Which transducer frequency provides higher
resolution but less penetration?
A) Lower frequency (2-5 MHz)
B) Higher frequency (7-15 MHz)
, C) No difference
D) Same frequency
Correct answer: B
Rationale: Higher frequency provides better axial and
lateral resolution but has greater attenuation (less
penetration).
7. Which of the following is the typical frequency
range for an abdominal ultrasound (adult)?
A) 1-3 MHz (penetrates deeper for large patients)
B) 2-5 MHz (curved array or phased array)
C) 7-12 MHz (superficial structures)
D) 15-20 MHz
Correct answer: B
Rationale: Abdominal imaging uses 2-5 MHz
(sometimes 1-3 MHz for larger patients) to balance
penetration and resolution.
8. What is the "piezoelectric effect"?
A) Electrical energy converted to mechanical sound
(and vice versa) in ultrasound transducers
B) Thermal effect of ultrasound
C) Doppler frequency shift
PRINCIPLES & INSTRUMENTATION (SPI)
EXAM | QUESTIONS WITH ANSWERS AND
RATIONALES
1. What is the primary physical principle of
ultrasound imaging?
A) Reflection of sound waves at tissue interfaces
(acoustic impedance differences)
B) X-ray attenuation
C) Magnetic resonance
D) Gamma ray emission
Correct answer: A
Rationale: Ultrasound relies on reflection (echoes) of
high-frequency sound waves at boundaries of tissues
with different acoustic impedances.
2. What is "acoustic impedance" (Z) in ultrasound?
A) Speed of sound in tissue multiplied by tissue
density (Z = density × sound velocity)
B) Frequency of the transducer
C) Amplitude of the wave
,D) Wavelength of the sound
Correct answer: A
Rationale: Acoustic impedance determines how
much sound is reflected at an interface. The greater
the impedance mismatch, the stronger the echo.
3. Which of the following has the highest acoustic
impedance and appears brightest on ultrasound
(hyperechoic)?
A) Fluid (simple cyst)
B) Bone (very high impedance, strong reflector,
bright with posterior shadowing)
C) Blood
D) Fat
Correct answer: B
Rationale: Bone has very high acoustic impedance
causing almost complete reflection and posterior
acoustic shadowing.
4. Which of the following appears anechoic (black) on
ultrasound and demonstrates posterior acoustic
enhancement (brightness behind)?
A) Simple cyst (fluid)
,B) Bone
C) Calcification
D) Kidney stone
Correct answer: A
Rationale: Simple fluid is anechoic and allows sound
to pass through, causing increased through-
transmission (posterior enhancement).
5. What is the normal range of sound velocities in soft
tissue used for ultrasound calibration?
A) 100 m/s
B) 1540 m/s (approximately 1540-1580 m/s for most
soft tissue)
C) 340 m/s (speed in air)
D) 5000 m/s (speed in bone)
Correct answer: B
Rationale: Ultrasound machines are calibrated to an
average soft tissue speed of 1540 m/s (1.54 mm/μs).
6. Which transducer frequency provides higher
resolution but less penetration?
A) Lower frequency (2-5 MHz)
B) Higher frequency (7-15 MHz)
, C) No difference
D) Same frequency
Correct answer: B
Rationale: Higher frequency provides better axial and
lateral resolution but has greater attenuation (less
penetration).
7. Which of the following is the typical frequency
range for an abdominal ultrasound (adult)?
A) 1-3 MHz (penetrates deeper for large patients)
B) 2-5 MHz (curved array or phased array)
C) 7-12 MHz (superficial structures)
D) 15-20 MHz
Correct answer: B
Rationale: Abdominal imaging uses 2-5 MHz
(sometimes 1-3 MHz for larger patients) to balance
penetration and resolution.
8. What is the "piezoelectric effect"?
A) Electrical energy converted to mechanical sound
(and vice versa) in ultrasound transducers
B) Thermal effect of ultrasound
C) Doppler frequency shift
