ARDMS SPI (Sonography Principles & Instrumentation) Exam — Questions and Answers

Question 1: Which of the following statements is true regarding the relationship between axial and lateral resolution?

Axial resolution is typically better than lateral resolution in the far field.
Lateral resolution is primarily determined by the spatial pulse length.
Axial resolution remains constant with depth, while lateral resolution varies. (Correct answer)
Both axial and lateral resolution are independent of imaging depth.

Correct answer: Axial resolution remains constant with depth, while lateral resolution varies.

Axial resolution is determined by the spatial pulse length, which does not change as the beam travels through tissue. Therefore, axial resolution is constant at all depths. Lateral resolution, however, is determined by the beam width. The beam width changes with depth, being narrowest at the focal zone and widening in the near and far fields. This means lateral resolution varies with depth.

Question 2: What is the primary purpose of the matching layer in a transducer?

Increase the transducer's center frequency
Protect the piezoelectric element from mechanical damage
Absorb backward-propagating sound waves
Reduce acoustic impedance mismatch between crystal and tissue (Correct answer)

Correct answer: Reduce acoustic impedance mismatch between crystal and tissue

The matching layer minimizes reflection at the crystal-tissue interface by presenting an intermediate acoustic impedance, maximizing energy transmission.

Question 3: In color Doppler, increasing the color box angle (steering) away from perpendicular to the vessel:

Reduces the detectable velocity range
Eliminates aliasing
Improves Doppler angle and increases color sensitivity (Correct answer)
Increases the PRF automatically

Correct answer: Improves Doppler angle and increases color sensitivity

Steering the color box to achieve a smaller insonation angle increases the cosine factor, producing larger frequency shifts and better color filling.

Question 4: Which statement about slice-thickness (elevational) artifacts is true?

They appear as multiple reflections in the axial direction
They are eliminated by dynamic receive focusing
They cause structures outside the image plane to be superimposed on the image (Correct answer)
They only occur with high-frequency transducers

Correct answer: They cause structures outside the image plane to be superimposed on the image

Because the elevation beam is relatively thick, off-plane structures contribute echoes that create partial-volume artifacts.

Question 5: In pulsed wave Doppler, aliasing occurs when the Doppler shift frequency exceeds:

One-half the pulse repetition frequency (Nyquist limit) (Correct answer)
The frame rate
The wall filter setting
The center frequency of the transducer

Correct answer: One-half the pulse repetition frequency (Nyquist limit)

Aliasing occurs when the detected Doppler shift exceeds the Nyquist limit, which is half the PRF.

Question 6: Spectral broadening on a Doppler waveform indicates:

Optimal angle of insonation has been achieved
Increased downstream vascular resistance
Laminar flow with uniform velocities throughout the vessel
A wide range of velocities simultaneously present within the sample volume (Correct answer)

Correct answer: A wide range of velocities simultaneously present within the sample volume

Spectral broadening occurs when multiple velocity components are detected within the sample volume, filling in the clear spectral window beneath the waveform envelope.

Question 7: Increasing the persistence (temporal averaging) setting in color Doppler will:

Eliminate aliasing artifact
Smooth the color display but reduce temporal resolution (Correct answer)
Increase the PRF automatically
Improve detection of pulsatile rapid flow changes

Correct answer: Smooth the color display but reduce temporal resolution

Higher persistence averages more frames, producing a smoother color image but blurring rapid phasic changes in flow.

Question 8: A 5 MHz transducer in soft tissue (c = 1540 m/s) produces a wavelength of approximately:

0.62 mm
3.1 mm
0.31 mm (Correct answer)
0.03 mm

Correct answer: 0.31 mm

λ = c/f = 1540/5,000,000 ≈ 0.308 mm ≈ 0.31 mm.

Question 9: A sonographer notes that the peak systolic velocity (PSV) appears falsely elevated when the sample volume is placed near a vessel bifurcation. What artifact is most likely responsible?

Mirror image artifact
Intrinsic spectral broadening from a wide Doppler beam width at that depth (Correct answer)
Range ambiguity
Aliasing

Correct answer: Intrinsic spectral broadening from a wide Doppler beam width at that depth

Intrinsic spectral broadening occurs because the Doppler beam has finite width; near a bifurcation the beam may intercept multiple vessels or disturbed flow regions, artificially broadening and elevating the displayed spectrum.

Question 10: Spatial compounding improves image quality by:

Averaging frames from multiple steering angles to reduce speckle and improve contrast resolution (Correct answer)
Widening the transmit beam for faster acquisition
Applying harmonic filtering to the receive signal
Transmitting at multiple frequencies simultaneously

Correct answer: Averaging frames from multiple steering angles to reduce speckle and improve contrast resolution

Compounding averages images steered from several angles, reducing coherent speckle and improving contrast and boundary definition.

Question 11: A sonographer compares current QA phantom images to baseline and notes reduced image brightness at depth despite unchanged gain settings. What is the most likely cause?

Transducer sensitivity has decreased due to element degradation (Correct answer)
The phantom has been stored too cold
The monitor brightness has increased
The PRF was inadvertently lowered

Correct answer: Transducer sensitivity has decreased due to element degradation

Decreased transducer sensitivity from element aging or damage reduces the amplitude of returning echoes, manifesting as reduced brightness at depth.

Question 12: In power Doppler imaging compared to conventional color Doppler, which of the following is TRUE?

Power Doppler uses a lower PRF
Power Doppler displays directional flow information
Power Doppler is more sensitive to low-velocity flow (Correct answer)
Power Doppler has less flash artifact

Correct answer: Power Doppler is more sensitive to low-velocity flow

Power Doppler maps the amplitude (power) of the Doppler signal, making it more sensitive to slow flow but sacrificing directional information.

Question 13: Acoustic shadowing posterior to a gallstone occurs because the stone:

Bends the beam away from its original path
Reflects and absorbs most of the incident ultrasound, leaving reduced energy beyond it (Correct answer)
Creates reverberation that fills the posterior region with echoes
Speeds up the ultrasound beam causing registration errors

Correct answer: Reflects and absorbs most of the incident ultrasound, leaving reduced energy beyond it

Gallstones strongly reflect and absorb ultrasound, resulting in little energy passing through to generate echoes posterior to the stone.

Question 14: The ALARA principle in diagnostic ultrasound instructs operators to:

Keep acoustic output as low as reasonably achievable while obtaining diagnostic information (Correct answer)
Avoid Doppler modes in all obstetric exams
Always use maximum power for best image quality
Limit scanning time to no more than 5 minutes per session

Correct answer: Keep acoustic output as low as reasonably achievable while obtaining diagnostic information

ALARA (As Low As Reasonably Achievable) requires using the minimum acoustic output necessary to obtain clinically useful images.

Question 15: The pulsatility index (PI) is calculated as:

(PSV − EDV) / mean velocity (Correct answer)
(PSV + EDV) / PSV
EDV / PSV
PSV / EDV

Correct answer: (PSV − EDV) / mean velocity

The Pulsatility Index = (Peak Systolic Velocity − End Diastolic Velocity) / Mean Velocity, providing a measure of downstream resistance.

Question 16: The duty factor of a pulsed ultrasound system is defined as:

Peak intensity divided by average intensity
Frequency divided by propagation speed
Pulse duration divided by pulse repetition period (Correct answer)
Number of pulses per second

Correct answer: Pulse duration divided by pulse repetition period

Duty factor = pulse duration (on-time) / pulse repetition period (on+off time), indicating the fraction of time the transducer is actively transmitting.

Question 17: Which of the following operator adjustments would lead to a degradation of lateral resolution?

Activating tissue harmonic imaging
Increasing the imaging depth (Correct answer)
Decreasing the overall gain
Increasing the number of focal zones

Correct answer: Increasing the imaging depth

Lateral resolution is the ability to distinguish two structures that are side-by-side, perpendicular to the beam's axis. It is determined by the beam width. As the ultrasound beam travels deeper into the body, it naturally diverges or widens, especially in the far field beyond the focal zone. This increased beam width at greater depths degrades lateral resolution.

Question 18: In the Doppler equation, doubling the transmitted frequency while keeping all other variables constant will have what effect on the detected Doppler shift?

The Doppler shift will quadruple
The Doppler shift will be halved
The Doppler shift will double (Correct answer)
The Doppler shift will remain unchanged

Correct answer: The Doppler shift will double

Since Δf = 2f₀v cosθ / c, the Doppler shift is directly proportional to the transmitted frequency f₀; doubling f₀ doubles Δf when velocity, angle, and speed of sound remain constant.

Question 19: Laminar flow in a vessel is characterized by:

Uniform velocity across the entire vessel lumen
Retrograde flow near the vessel walls
Concentric layers of blood moving at different velocities with fastest flow centrally (Correct answer)
Random, chaotic movement of blood cells in all directions

Correct answer: Concentric layers of blood moving at different velocities with fastest flow centrally

In laminar flow, blood moves in concentric layers (parabolic profile) with the fastest velocity at the center and slowest near the walls due to friction.

Question 20: Which transducer type uses a rotating or wobbling mechanical element to sweep the beam?

Linear array
Annular array
Phased array
Mechanical transducer (Correct answer)

Correct answer: Mechanical transducer

Mechanical transducers use a physically moving element to sweep the ultrasound beam across the imaging plane.

Question 21: A sonographer observes that the intensity of the ultrasound beam has decreased by 3 dB. This corresponds to what change in intensity?

A twofold decrease (Correct answer)
A threefold decrease
A twofold increase
A tenfold decrease

Correct answer: A twofold decrease

The decibel (dB) scale is logarithmic. A change of -3 dB represents a halving, or a twofold decrease, in intensity. Conversely, a +3 dB change represents a doubling of intensity. A -10 dB change corresponds to a tenfold decrease. [12, 16]

Question 22: At normal incidence, what determines the fraction of sound intensity reflected at an interface?

The difference in acoustic impedance between the two media (Correct answer)
The frequency of the transducer
The beam diameter at the interface
The depth of the interface

Correct answer: The difference in acoustic impedance between the two media

The reflection coefficient at normal incidence depends solely on the acoustic impedances of the two media.

Question 23: Acoustic shadowing posterior to a gallstone is caused by:

Constructive interference of side lobes behind the stone
Refraction of the beam around the calcification
Total reflection and high attenuation by the stone preventing sound transmission (Correct answer)
Increased transmission through the stone's interface

Correct answer: Total reflection and high attenuation by the stone preventing sound transmission

Calcifications strongly reflect and absorb sound, so little energy passes through to deeper tissues, producing a dark shadow posteriorly.

Question 24: The Doppler equation shows that detected frequency shift is zero when the angle between the beam and flow direction is:

60 degrees
45 degrees
90 degrees (perpendicular) (Correct answer)
0 degrees (parallel)

Correct answer: 90 degrees (perpendicular)

At 90 degrees, the cosine of the angle equals zero, making the Doppler frequency shift zero regardless of actual velocity; Doppler is therefore unusable at this angle.

Question 25: Increasing transducer frequency to improve resolution is limited primarily by:

Lower pulse repetition frequency
Greater acoustic attenuation reducing penetration depth (Correct answer)
Increased slice thickness
Increased lateral resolution

Correct answer: Greater acoustic attenuation reducing penetration depth

Higher frequencies are attenuated more rapidly in tissue, limiting the usable imaging depth.

Question 26: The primary function of the scan converter in an ultrasound system is to:

Format the echo data from the spoke format into a video format for display. (Correct answer)
Convert electrical signals into acoustic pulses.
Amplify the weak returning echo signals.
Calculate the Doppler shift from moving red blood cells.

Correct answer: Format the echo data from the spoke format into a video format for display.

The scan converter, or image processor, is a digital memory component that receives echo data from the receiver. Its main job is to reformat this data, which is acquired in a spoke or line-by-line format (like polar coordinates for a sector transducer), into a standard raster scan or video format (Cartesian coordinates) that can be displayed on a monitor.

Question 27: Apodization in ultrasound beamforming refers to:

Adjusting time gain compensation at each depth
Increasing transmit power to all elements equally
Varying element excitation amplitude across the aperture to reduce side lobes (Correct answer)
Setting the pulse repetition frequency

Correct answer: Varying element excitation amplitude across the aperture to reduce side lobes

Apodization applies a weighting window (e.g., Hanning) to element amplitudes to suppress side lobes at a slight cost to main-lobe width.

Question 28: Using electrical steering technology, spatial compounding can:

Enhance shadowing artifact
Decrease speckle artifact (Correct answer)
Improve temporal resolution
Increase frame rate

Correct answer: Decrease speckle artifact

Spatial compounding acquires multiple scan lines from different angles using electrical steering and then averages them to create a single composite image. By viewing structures from various perspectives, random noise and speckle artifacts, which are angle-dependent, are significantly reduced. This leads to a smoother image with improved contrast resolution and better visualization of tissue textures.

Question 29: Elevated end-diastolic velocity (EDV) in an arterial waveform typically indicates:

Proximal arterial occlusion
Arterial vasospasm
Low downstream vascular resistance (high diastolic demand) (Correct answer)
High downstream vascular resistance

Correct answer: Low downstream vascular resistance (high diastolic demand)

High EDV indicates continued forward flow throughout diastole, reflecting low downstream resistance from vasodilation, as seen in low-resistance organs like the kidney or brain.

Question 30: In a linear array transducer, electronic focusing in the elevation plane is achieved by:

Changing the PRF
Time-delay steering of individual elements
Variable aperture selection
A fixed acoustic lens (Correct answer)

Correct answer: A fixed acoustic lens

Elevation-plane focusing in a linear array is fixed and accomplished by a curved acoustic lens bonded to the transducer face.

Question 31: In pulsed-wave Doppler, increasing the depth of the sample gate will require the system to:

Increase PRF to maintain sensitivity
Decrease PRF to allow sufficient time for echoes to return from the greater depth (Correct answer)
Decrease wall filter settings
Increase transmit frequency

Correct answer: Decrease PRF to allow sufficient time for echoes to return from the greater depth

Greater sample gate depth requires a longer round-trip travel time for the pulse echo, so PRF must be decreased to avoid range ambiguity.

Question 32: During a renal ultrasound, a sonographer places the color Doppler box over a suspected kidney stone. A rapidly changing, mosaic pattern of color appears immediately posterior to the hyperechoic structure, despite the absence of true blood flow. This specific finding is known as:

Reverberation artifact
Crosstalk artifact
Power Doppler bloom
Twinkle artifact (Correct answer)

Correct answer: Twinkle artifact

The twinkle artifact is a color Doppler phenomenon seen as a rapidly changing mixture of red and blue pixels posterior to a strongly reflecting, rough-surfaced object like a kidney stone. [17, 21] It is thought to be caused by intrinsic machine noise or random phase shifts from the rough surface creating a 'noisy' Doppler signal. [20] It is a useful sign that increases confidence in identifying calcifications. [21]

Question 33: Which of the following best defines the acoustic property 'stiffness' of a medium in the context of sound propagation?

The attenuation coefficient of the medium
The medium's resistance to being compressed (Correct answer)
The wavelength of sound within the medium
The medium's density per unit volume

Correct answer: The medium's resistance to being compressed

Stiffness (bulk modulus) is the medium's resistance to compression; stiffer media transmit sound faster because they restore disturbed particles more quickly.

Question 34: How does increasing ultrasound frequency affect attenuation in soft tissue?

Attenuation decreases
Attenuation is unaffected
Attenuation increases (Correct answer)
Attenuation first decreases then increases

Correct answer: Attenuation increases

Attenuation increases with frequency because higher-frequency sound waves are more readily absorbed and scattered by tissue.

Question 35: A post-stenotic waveform showing low PSV, slow systolic acceleration time, and absence of the early diastolic reversal component is described as:

Normal biphasic
Hyperemic monophasic
Tardus-parvus (Correct answer)
High-resistance triphasic

Correct answer: Tardus-parvus

Tardus-parvus (Latin: slow-small) describes the dampened, delayed, monophasic waveform seen distal to a hemodynamically significant stenosis or occlusion.

Question 36: Which of the following phantom measurements is most useful for evaluating the effectiveness of harmonic imaging compared to fundamental imaging?

Caliper distance measurement
Doppler velocity accuracy
Contrast-detail analysis comparing anechoic cyst visibility (Correct answer)
Depth of penetration test

Correct answer: Contrast-detail analysis comparing anechoic cyst visibility

Comparing anechoic cyst detectability between fundamental and harmonic modes reveals harmonic imaging's improvement in contrast resolution by reducing reverberation and clutter.

Question 37: Which of the following describes the piezoelectric effect as it is utilized in an ultrasound transducer during sound wave reception?

Conversion of acoustic energy into light.
Conversion of a pressure wave into an electrical signal. (Correct answer)
Conversion of an electrical signal into a mechanical vibration.
Conversion of electrical energy into heat.

Correct answer: Conversion of a pressure wave into an electrical signal.

The piezoelectric effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress. During reception, the returning sound echoes (which are pressure waves) cause the piezoelectric crystals to vibrate, and this mechanical deformation is converted back into an electrical signal for processing by the ultrasound system.

Question 38: A heavily damped transducer will produce:

Longer pulses and better axial resolution
Higher amplitude and better penetration
Shorter pulses and better axial resolution (Correct answer)
Narrower beams and better lateral resolution

Correct answer: Shorter pulses and better axial resolution

Heavy damping reduces ringing, shortening the pulse and thus improving axial resolution.

Question 39: The far field (Fraunhofer zone) of an unfocused transducer is characterized by:

Constant beam width
Beam convergence and improving lateral resolution
Improved axial resolution
Beam divergence and degrading lateral resolution (Correct answer)

Correct answer: Beam divergence and degrading lateral resolution

In the far field the beam diverges, widening the beam and worsening lateral resolution.

Question 40: The mechanical index (MI) is used to estimate the risk of:

Thermal damage to tissue
Grating lobe formation
Non-thermal (cavitation) bioeffects (Correct answer)
Image aliasing

Correct answer: Non-thermal (cavitation) bioeffects

The Mechanical Index estimates the likelihood of cavitation and other non-thermal mechanical bioeffects from ultrasound exposure.

Question 41: In a spectral Doppler waveform, spectral broadening refers to:

Increased pulsatility of the waveform
Aliasing wrapping the waveform below baseline
Widening of the frequency band representing a range of flow velocities within the sample volume (Correct answer)
An increase in peak systolic velocity

Correct answer: Widening of the frequency band representing a range of flow velocities within the sample volume

Spectral broadening occurs when multiple velocities are present in the sample volume, widening the spectral window and filling in the clear area beneath the waveform envelope.

Question 42: During weekly QA, a sonographer notices the lateral resolution has worsened compared to baseline. What is the most likely cause?

The speed-of-sound calibration changed
Phantom temperature dropped below 20°C
The TGC was adjusted incorrectly
One or more transducer elements have failed (Correct answer)

Correct answer: One or more transducer elements have failed

Failed or weak transducer elements degrade the aperture and focusing ability of the array, directly worsening lateral resolution.

Question 43: Non-specular (diffuse) reflectors differ from specular reflectors in that they:

Only reflect when struck perpendicularly
Scatter sound in many directions regardless of beam angle (Correct answer)
Produce echoes proportional to acoustic impedance alone
Require higher frequency to produce echoes

Correct answer: Scatter sound in many directions regardless of beam angle

Non-specular (diffuse) reflectors have irregular or small surfaces that scatter sound in all directions, making them angle-independent.

Question 44: A quality assurance program requires testing the system's ability to place echoes in their correct positions on the display, ensuring that a pin target appears in the same location whether imaged from the top or side of the phantom. Which parameter does this test evaluate?

Dynamic range
Axial resolution
Uniformity
Registration accuracy (Correct answer)

Correct answer: Registration accuracy

Registration accuracy is the ability of the system to display echoes in their proper anatomical positions on the screen. This test ensures that the system's internal coordinate system is correctly calibrated, so structures are mapped accurately in A-mode, B-mode, and M-mode.

Question 45: What does the wall filter (high-pass filter) in Doppler mode eliminate?

Side lobe signals from adjacent structures
High-frequency signals from fast blood flow
Mirror image artifacts
Low-frequency signals from slow-moving vessel walls (Correct answer)

Correct answer: Low-frequency signals from slow-moving vessel walls

The wall filter removes low-frequency, high-amplitude signals generated by slow-moving vessel walls and surrounding tissue.

Question 46: A QA test reveals that the on-screen distance measurement reads 5.2 cm for a structure the phantom certifies as 5.0 cm. What does this indicate?

Excessive focal zone depth
Caliper or distance accuracy error exceeding acceptable tolerance (Correct answer)
Artifact from multipath reflection
Normal variation within expected system noise

Correct answer: Caliper or distance accuracy error exceeding acceptable tolerance

A 4% error in distance measurement suggests a calibration issue with the system's speed-of-sound assumption or caliper circuitry.

Question 47: Tissue harmonic imaging improves lateral resolution compared to fundamental imaging because harmonic signals:

Are generated at higher amplitude near the transducer face
Travel at higher speed in tissue
Are strongest near the beam axis where pressure is highest, reducing side lobes (Correct answer)
Use a wider aperture

Correct answer: Are strongest near the beam axis where pressure is highest, reducing side lobes

Harmonic energy is concentrated near the beam axis, reducing clutter from side lobes and grating lobes.

Question 48: In a QA protocol for Doppler systems, a string phantom or flow phantom is used. What specific parameter does a string phantom test?

Volume flow rate accuracy
Pulse repetition frequency calibration
Velocity accuracy and angle dependence of Doppler measurements (Correct answer)
Color flow sensitivity at depth

Correct answer: Velocity accuracy and angle dependence of Doppler measurements

A string phantom moves a target at a known velocity, allowing the sonographer to verify that the system accurately reports Doppler-derived velocity at various beam-to-target angles.

Question 49: A color Doppler image of the carotid artery shows color signal extending beyond the vessel wall into surrounding soft tissue. This is called:

Mirror image artifact
Twinkling artifact
Color bleed (blooming) (Correct answer)
Color aliasing

Correct answer: Color bleed (blooming)

Color bleed or blooming occurs when gain is set too high, causing color to spill beyond true vessel margins.

Question 50: Critical angle refraction in ultrasound occurs when:

The frequency exceeds 10 MHz
Attenuation equals the impedance mismatch
The refracted beam travels parallel to the interface (90° refraction) (Correct answer)
The incident beam strikes perpendicular to the interface

Correct answer: The refracted beam travels parallel to the interface (90° refraction)

At the critical angle, refraction bends the transmitted beam to 90°, meaning it travels along the interface and no energy enters medium 2.

Question 51: The pulse repetition frequency (PRF) setting directly affects which Doppler parameter?

Beam steering angle
Wall filter cutoff
Spectral baseline position only
Maximum detectable velocity (Nyquist limit) (Correct answer)

Correct answer: Maximum detectable velocity (Nyquist limit)

The Nyquist limit is equal to PRF/2, so increasing PRF raises the maximum velocity that can be displayed without aliasing.

Question 52: According to the U.S. Food and Drug Administration (FDA) guidelines, which principle should sonographers always follow to minimize patient exposure to ultrasound energy?

The Principle of Maximum Intensity
The Doppler Shift Principle
The As Low As Reasonably Achievable (ALARA) Principle (Correct answer)
The Inverse Square Law Principle

Correct answer: The As Low As Reasonably Achievable (ALARA) Principle

The FDA, along with other regulatory and professional bodies like the AIUM, advocates for the prudent use of diagnostic ultrasound by following the As Low As Reasonably Achievable (ALARA) principle. This means using the lowest output power and shortest scan time that will yield diagnostic-quality images, thereby minimizing the patient's exposure to potential bioeffects.

Question 53: In the context of obstetric ultrasound, TIS (Soft Tissue Thermal Index) is preferred over TIB (Bone Thermal Index) during which trimester?

First trimester, before ossification is significant (Correct answer)
Second trimester, after limb bones are fully ossified
TIS and TIB are interchangeable throughout pregnancy
Third trimester only

Correct answer: First trimester, before ossification is significant

TIS is used in the first trimester when fetal ossification is minimal; TIB becomes more relevant later when bone absorbs more ultrasound energy and heats significantly.

Question 54: Which operator action would most effectively reduce thermal bioeffect risk without eliminating diagnostic utility?

Switching from 2D grayscale to pulsed Doppler to shorten total scan time
Turning off harmonic imaging to increase fundamental signal strength
Increasing frequency to improve resolution at the cost of penetration
Reducing output power and using gain controls to compensate image brightness (Correct answer)

Correct answer: Reducing output power and using gain controls to compensate image brightness

Reducing output power lowers acoustic energy deposition, while compensating with receive gain maintains image quality without additional thermal risk.

Question 55: Which of the following interfaces reflects nearly 100% of incident sound energy?

Soft tissue–air interface (Correct answer)
Blood–muscle interface
Muscle–liver interface
Soft tissue–fat interface

Correct answer: Soft tissue–air interface

The acoustic impedance mismatch between soft tissue and air is extreme, causing nearly total reflection and no transmission.

Question 56: When multiple focal zones are used, what is the trade-off?

Reduced resolution at all depths
Improved resolution at multiple depths but reduced frame rate (Correct answer)
Improved resolution throughout but increased depth
Increased frame rate

Correct answer: Improved resolution at multiple depths but reduced frame rate

Each additional focal zone requires an extra transmit pulse, increasing scan time and lowering frame rate in exchange for better lateral resolution at those depths.

Question 57: A sonographer performs a sensitivity test as part of a quality assurance protocol. This test is designed to assess the system's ability to:

detect and display weak echoes from deep structures. (Correct answer)
accurately measure the size of an anechoic structure.
distinguish between two closely spaced objects perpendicular to the beam.
maintain uniform brightness of echoes from similar structures at the same depth.

Correct answer: detect and display weak echoes from deep structures.

Sensitivity, also known as maximum depth of penetration, evaluates the ability of the ultrasound system to detect and display the weakest-amplitude echoes from reflectors located deep within a phantom. It is a measure of the system's overall performance in penetrating tissue and receiving faint signals.

Question 58: Side lobes in ultrasound transducers are most problematic because they:

Improve lateral resolution at depth
Create artifact echoes that appear to originate from the main beam (Correct answer)
Increase axial resolution
Reduce the dynamic range of the system

Correct answer: Create artifact echoes that appear to originate from the main beam

Side lobes radiate energy off-axis; reflectors in their path produce echoes that the system incorrectly places along the main beam axis, creating artifacts.

Question 59: A phased array transducer steers and focuses the beam primarily by adjusting:

Time delays applied to individual element firings (Correct answer)
The size of the active aperture only
The frequency of each element independently
The physical curvature of the array

Correct answer: Time delays applied to individual element firings

Phased arrays use programmable electronic time delays across all elements to steer and dynamically focus the beam in real time.

Question 60: Which of the following changes would increase the maximum velocity that can be measured without aliasing using PW Doppler?

Increasing the transmit frequency
Increasing the Doppler angle to 60°
Decreasing the sample gate depth (which allows a higher PRF) (Correct answer)
Increasing the wall filter cutoff

Correct answer: Decreasing the sample gate depth (which allows a higher PRF)

Shallower gate depth allows a higher PRF (less round-trip time needed), which raises the Nyquist limit and allows higher velocities to be measured without aliasing.

Question 61: Which of the following properties of a medium has the most significant influence on the propagation speed of an acoustic wave?

Temperature
Viscosity
Density
Stiffness (Correct answer)

Correct answer: Stiffness

Propagation speed is primarily determined by the stiffness (or bulk modulus) and density of the medium. Of these two, stiffness has the greater influence. Sound travels faster in stiffer materials. While density does affect speed (higher density generally leads to slower speed), its effect is less pronounced than that of stiffness. For example, bone is much denser than soft tissue, but it is also significantly stiffer, resulting in a much higher propagation speed. [11, 13]

Question 62: In harmonic imaging, the image is formed from the _____ harmonic frequency.

Second (2f₀) (Correct answer)
Third (3f₀)
Sub-harmonic (f₀/2)
Fundamental (transmitted)

Correct answer: Second (2f₀)

Tissue harmonic imaging uses the second harmonic (twice the transmitted frequency) generated by nonlinear propagation.

Question 63: Which control is adjusted to change the size of the color Doppler sample box?

PRF
Ensemble length
Color box size/region of interest (Correct answer)
Color gain

Correct answer: Color box size/region of interest

The color box size or region of interest control determines the area over which color Doppler information is displayed, directly affecting frame rate.

Question 64: Which of the following best describes the role of the physics QA physicist or qualified medical physicist in an ultrasound department?

Writing billing codes for ultrasound examinations
Overseeing and validating the QA program, interpreting results, and recommending corrective actions (Correct answer)
Calibrating DICOM network connections between scanners
Performing all clinical scans requiring QA phantom images

Correct answer: Overseeing and validating the QA program, interpreting results, and recommending corrective actions

The medical physicist oversees the QA program, interprets performance data, identifies equipment deficiencies, and recommends or validates corrective actions before systems return to clinical use.

Question 65: What is the primary purpose of the fast Fourier transform (FFT) in spectral Doppler ultrasound?

To convert the raw Doppler audio signal into a frequency spectrum displayed over time (Correct answer)
To increase the pulse repetition frequency
To correct for angle errors automatically
To generate color-flow images

Correct answer: To convert the raw Doppler audio signal into a frequency spectrum displayed over time

The FFT mathematically decomposes the complex Doppler signal into its individual frequency components, which are then displayed as a spectrum of velocities over time on the spectral waveform.

Question 66: Which tissue type has the highest acoustic propagation speed?

Soft tissue
Fat
Bone (Correct answer)
Air

Correct answer: Bone

Bone has the highest stiffness among listed tissues, giving it the greatest propagation speed (~3500 m/s).

Question 67: Which approach can improve both axial resolution and penetration simultaneously in modern ultrasound?

Reducing the number of active elements
Using a single high-frequency narrow-band pulse
Increasing pulse repetition frequency
Broadband multi-frequency transducers combined with coded excitation (Correct answer)

Correct answer: Broadband multi-frequency transducers combined with coded excitation

Broadband transducers with coded excitation allow penetration at lower frequencies while compressing the pulse for good axial resolution.

Question 68: Which of the following correctly describes the relationship between color Doppler frame rate and color box size?

Wider color box increases frame rate because fewer pulses are needed
Deeper color box increases frame rate by lowering PRF
Narrower color box increases frame rate by reducing the number of scan lines required (Correct answer)
Color box size has no effect on frame rate

Correct answer: Narrower color box increases frame rate by reducing the number of scan lines required

A narrower color box requires fewer scan lines per frame, allowing the system to complete each frame more quickly and increasing frame rate.

Question 69: In a standard spectral Doppler display, the vertical (y-axis) represents:

Depth of the sample volume gate
Relative signal power or amplitude
Doppler frequency shift (displayed as velocity after angle correction) (Correct answer)
Time elapsed during the cardiac cycle

Correct answer: Doppler frequency shift (displayed as velocity after angle correction)

The y-axis in spectral Doppler displays the Doppler frequency shift, which is converted to velocity using angle correction, while the x-axis represents time.

Question 70: The resistivity index (RI) is calculated as:

(PSV − EDV) / PSV (Correct answer)
(PSV − EDV) / EDV
(PSV + EDV) / 2
PSV / EDV

Correct answer: (PSV − EDV) / PSV

The Resistivity Index = (Peak Systolic Velocity − End Diastolic Velocity) / Peak Systolic Velocity, reflecting downstream vascular resistance.

Question 71: Which artifact results from acoustic enhancement behind a fluid-filled cyst?

Acoustic shadowing
Side-lobe artifact
Mirror image artifact
Posterior acoustic enhancement (Correct answer)

Correct answer: Posterior acoustic enhancement

Fluid attenuates sound less than surrounding tissue, so structures behind a cyst appear brighter — posterior acoustic enhancement.

Question 72: In M-mode echocardiography, what does the vertical axis represent?

Velocity
Frequency shift
Depth (distance from transducer) (Correct answer)
Time

Correct answer: Depth (distance from transducer)

In M-mode, the vertical axis shows depth from the transducer while the horizontal axis represents time.

Question 73: The systolic-to-diastolic (S/D) ratio used in obstetric Doppler is calculated as:

EDV / PSV
PSV / EDV (Correct answer)
(PSV - EDV) / PSV
(PSV - EDV) / TAMV

Correct answer: PSV / EDV

The S/D ratio = PSV / EDV and is commonly used in umbilical artery Doppler to assess placental resistance; it cannot be calculated when EDV is absent.

Question 74: Which index displayed on modern ultrasound systems specifically relates to the risk of acoustic cavitation?

Dynamic Range Index
Thermal Index (TI)
Pulsatility Index
Mechanical Index (MI) (Correct answer)

Correct answer: Mechanical Index (MI)

The Mechanical Index (MI) quantifies the likelihood of cavitation by comparing peak negative pressure to the square root of frequency.

Question 75: What is the primary purpose of adjusting the focal zone position on an ultrasound system?

To increase overall image brightness
To minimize shadowing artifact
To reduce frame rate
To maximize lateral resolution at a specific depth (Correct answer)

Correct answer: To maximize lateral resolution at a specific depth

The focal zone is positioned at the depth of interest to minimize beam width and maximize lateral resolution at that location.

Question 76: When a tissue-mimicking phantom is scanned with a transducer at a frequency significantly higher than the phantom's design frequency, how does this typically affect the penetration depth result?

Penetration depth doubles due to improved axial resolution
Penetration depth is unchanged because the phantom speed of sound is fixed
Penetration depth decreases because higher-frequency sound attenuates faster (Correct answer)
Penetration depth increases because resolution improves

Correct answer: Penetration depth decreases because higher-frequency sound attenuates faster

Acoustic attenuation increases with frequency, so scanning at a higher frequency than the phantom's design frequency results in greater signal loss per centimeter and shallower penetration.

Question 77: A transducer with a low Q-factor is characterized by:

A wide bandwidth and a short spatial pulse length. (Correct answer)
A narrow bandwidth and a long spatial pulse length.
A narrow bandwidth and a short spatial pulse length.
A wide bandwidth and a long spatial pulse length.

Correct answer: A wide bandwidth and a short spatial pulse length.

The Quality factor (Q-factor) is the ratio of the center frequency to the bandwidth. A low Q-factor indicates a wide (or broad) bandwidth. Transducers with a wide bandwidth are heavily damped, which results in a short spatial pulse length (SPL). This combination is ideal for diagnostic imaging because a short SPL provides good axial resolution.

Question 78: The Pulsatility Index (PI) is calculated as:

(PSV + EDV) / 2
(PSV - EDV) / TAMV (Correct answer)
(PSV - EDV) / PSV
PSV / EDV

Correct answer: (PSV - EDV) / TAMV

PI = (PSV - EDV) / TAMV (time-averaged mean velocity); unlike RI, PI can exceed 1.0 and can be calculated even when end-diastolic flow is zero or reversed.

Question 79: The continuity equation in hemodynamics states that flow rate is conserved, meaning:

Pressure is constant throughout the circulation
Viscosity determines velocity distribution
Resistance is equal in all vessel segments
Cross-sectional area × velocity is constant at any point along a vessel (Correct answer)

Correct answer: Cross-sectional area × velocity is constant at any point along a vessel

The continuity equation (Q = A × V) states that volumetric flow rate equals cross-sectional area times velocity and is conserved, so a smaller area requires higher velocity.

Question 80: Which of the following is a recognized method to correct for aliasing in color Doppler without switching to power Doppler?

Lowering the color scale (velocity range) further
Decreasing the transmit frequency
Increasing the color gain
Increasing the color scale (velocity range / PRF) or shifting the baseline (Correct answer)

Correct answer: Increasing the color scale (velocity range / PRF) or shifting the baseline

Increasing the color scale raises the Nyquist limit for color Doppler, and shifting the color baseline allows more dynamic range in one direction to accommodate higher velocities without aliasing.

Question 81: Harmonic imaging reduces which type of artifact compared to fundamental imaging?

Comet tail artifact
Enhancement
Near-field clutter and side lobe artifacts (Correct answer)
Shadowing

Correct answer: Near-field clutter and side lobe artifacts

Tissue harmonic imaging uses the second harmonic frequency generated within tissue, which reduces near-field clutter and side lobe artifacts.

Question 82: The depth of field (depth of focus) of an ultrasound beam refers to:

The maximum imaging depth at a given frequency
The range of depths over which lateral resolution remains acceptable (Correct answer)
The distance between the near field and the transducer face
The slice thickness in the elevation plane

Correct answer: The range of depths over which lateral resolution remains acceptable

Depth of field describes the axial extent around the focal point where lateral resolution stays within an acceptable limit.

Question 83: Which of the following is a primary advantage of Continuous-Wave (CW) Doppler over Pulsed-Wave (PW) Doppler?

It provides superior range resolution.
It uses a single crystal for both transmission and reception.
It offers better axial resolution in the image.
It is not limited by aliasing at high velocities. (Correct answer)

Correct answer: It is not limited by aliasing at high velocities.

Continuous-Wave (CW) Doppler continuously transmits and receives ultrasound, so it does not have a sampling rate (PRF) that limits velocity measurement. This allows it to accurately measure very high velocities without the aliasing artifact that affects Pulsed-Wave (PW) Doppler.

Question 84: Which imaging mode provides the highest temporal resolution for evaluating rapidly moving structures like heart valves?

M-mode (Correct answer)
Color Doppler
B-mode with high frame rate
3D volumetric imaging

Correct answer: M-mode

M-mode records a single scan line repeatedly at very high sampling rates (up to 1000 times/sec), giving superior temporal resolution.

Question 85: Acoustic impedance (Z) is calculated as:

Pressure / particle velocity squared
Density × propagation speed (Correct answer)
Frequency × wavelength
Attenuation coefficient / frequency

Correct answer: Density × propagation speed

Acoustic impedance Z = ρ × c, where ρ is the tissue density and c is the propagation speed.

Question 86: The Doppler angle cursor should be aligned parallel to which structure during angle correction?

The direction of blood flow (Correct answer)
The vessel wall perpendicular to flow
The beam axis
The transducer face

Correct answer: The direction of blood flow

The angle correction cursor must be aligned parallel to the direction of blood flow so that the cosine of the angle can accurately correct the measured velocity.

Question 87: Which of the following best explains why CW Doppler is NOT affected by aliasing?

CW Doppler uses phase-quadrature detection
CW Doppler uses a lower transmit frequency
CW Doppler applies a higher wall filter
CW Doppler continuously transmits and receives without a PRF limitation, so there is no Nyquist limit constraint (Correct answer)

Correct answer: CW Doppler continuously transmits and receives without a PRF limitation, so there is no Nyquist limit constraint

Because CW Doppler continuously transmits on one element and receives on another with no pulsed repetition interval, there is no PRF and therefore no Nyquist limit to cause aliasing.

Question 88: The PZT crystal in a linear phased array transducer is divided into 280 distinct active elements. This transducer has how many channels?

1
140
560
280 (Correct answer)

Correct answer: 280

In a phased array transducer, each distinct active PZT element is typically connected to its own independent electronic circuit, known as a channel. These channels allow for individual control of each element's excitation, enabling electronic steering and focusing of the ultrasound beam. Therefore, if a transducer has 280 active elements, it has 280 channels.

Question 89: A sonographer is using a transducer with a heavy backing material. Which of the following is a primary consequence of this design feature?

Improved axial resolution (Correct answer)
Increased spatial pulse length
Narrower bandwidth
Increased sensitivity

Correct answer: Improved axial resolution

The backing (or damping) material absorbs the backward-directed ultrasound energy and dampens the crystal's ringing. This shortens the spatial pulse length (SPL), which is crucial for improving axial resolution, the ability to distinguish two structures that are close to each other along the beam's path. A shorter SPL results in better axial resolution. Heavy damping leads to a wider bandwidth and decreased sensitivity.

Question 90: An ultrasound wave travels through two different media. If the propagation speed in the second medium is lower than in the first, what happens to the wavelength of the sound wave?

It decreases. (Correct answer)
It remains the same.
It becomes zero.
It increases.

Correct answer: It decreases.

The relationship between propagation speed (c), frequency (f), and wavelength (λ) is given by the formula c = f x λ. The frequency of the sound wave is determined by the transducer and does not change as it passes through different media. Therefore, if the propagation speed (c) decreases, the wavelength (λ) must also decrease to maintain the equality. [2, 22]

Question 91: A 'tardus parvus' waveform observed distal to a stenosis is characterized by:

Decreased PSV with prolonged systolic acceleration time (Correct answer)
Increased RI with elevated diastolic velocities
Normal PSV with absent diastolic flow
Increased PSV with normal systolic acceleration time

Correct answer: Decreased PSV with prolonged systolic acceleration time

Tardus parvus (Latin: slow-small) describes the dampened, delayed post-stenotic waveform with reduced peak systolic velocity and a slow, rounded systolic upstroke.

Question 92: Which transducer design characteristic MOST directly determines axial resolution?

Spatial pulse length (Correct answer)
Number of elements in the array
Element diameter
Focal depth

Correct answer: Spatial pulse length

Axial resolution equals half the spatial pulse length; shorter pulses (fewer cycles, higher frequency, greater damping) yield better axial resolution.

Question 93: While evaluating blood flow, a sonographer notices low-frequency, high-amplitude color signals originating from the vessel walls that obscure the true flow within the lumen. Which control should be adjusted to mitigate this specific artifact?

Color Gain
Doppler Angle
PRF/Scale
Wall Filter (Correct answer)

Correct answer: Wall Filter

The artifact described is clutter, or ghosting, which is caused by strong, low-frequency Doppler shifts from moving anatomy like vessel walls. [15] The Wall Filter is a high-pass filter specifically designed to eliminate these low-frequency signals, allowing the weaker, higher-frequency signals from blood flow to be displayed more clearly. [16]

Question 94: Which of the following would be MOST likely to increase the Thermal Index (TI) during a diagnostic ultrasound examination?

Switching from B-mode to Color Doppler (Correct answer)
Increasing the receiver gain
Decreasing the imaging depth
Using a lower frequency transducer

Correct answer: Switching from B-mode to Color Doppler

Switching to modes like Color Doppler or Pulsed-Wave Doppler generally increases the acoustic output and energy deposited in the tissue, leading to a higher Thermal Index (TI). Receiver gain only amplifies the returning echoes and does not change the transmitted power. Decreasing imaging depth or using a lower frequency transducer does not inherently increase the TI as significantly as changing to a higher-energy mode like Doppler.

Question 95: The process of reducing high-amplitude speckle noise while preserving edge detail in ultrasound images is best described as:

Harmonic imaging
Adaptive image processing (speckle reduction imaging) (Correct answer)
Time-gain compensation
Coded excitation

Correct answer: Adaptive image processing (speckle reduction imaging)

Adaptive speckle reduction algorithms analyze local image statistics to smooth homogeneous regions while retaining boundaries.

Question 96: A sonographer is using an annular array transducer to do an examination. In the near field of the image that is being presented, there is a horizontal band of dropout. Which PZT crystal ring damage does this most likely relate to?

Outermost ring
Middle ring
Innermost ring (Correct answer)
The resulting image would have a vertical band of dropout with an annular array transducer

Correct answer: Innermost ring

Annular array transducers use concentric ring-shaped PZT elements for focusing. Damage to an innermost ring specifically affects the central portion of the ultrasound beam, which corresponds to the near field of the image. This typically manifests as a horizontal band of dropout in the near field, as the central part of the image information is compromised.

Question 97: Frame rate in real-time ultrasound imaging is primarily limited by:

The speed of sound and imaging depth (Correct answer)
The patient's body habitus
The analog-to-digital conversion speed
The transducer element impedance

Correct answer: The speed of sound and imaging depth

Because sound must travel to the maximum depth and return before the next pulse is fired, greater depth forces a lower pulse repetition frequency and thus a lower frame rate.

Question 98: When a sound beam travels from muscle into fat, which phenomenon occurs because fat has a lower propagation speed?

Scattering
Refraction (Correct answer)
Specular reflection
Absorption

Correct answer: Refraction

Refraction occurs when sound crosses an interface at an oblique angle between media with different propagation speeds, causing the beam to bend.

Question 99: Which factor does NOT increase the risk of thermally induced bioeffects during an ultrasound exam?

Prolonged dwell time over a single region
Scanning over a region with elevated patient temperature (fever)
Increasing output power
Using harmonic imaging instead of fundamental frequency (Correct answer)

Correct answer: Using harmonic imaging instead of fundamental frequency

Harmonic imaging uses lower overall acoustic power and is generally considered safer thermally; in contrast, higher power, longer dwell time, and pre-existing fever all increase thermal risk.

Question 100: Compared to the AIUM 100mm test object, which is filled with a non-attenuating fluid, what is a primary advantage of using a tissue-equivalent (TE) phantom for routine quality assurance?

It is better for measuring the speed of sound.
It allows for the evaluation of grayscale and contrast resolution. (Correct answer)
It is less expensive to manufacture.
It is the only phantom that can measure axial resolution.

Correct answer: It allows for the evaluation of grayscale and contrast resolution.

Tissue-equivalent (TE) phantoms are made of materials that mimic the acoustic properties of soft tissue, including speed of sound, attenuation, and scattering. This allows for the subjective assessment of grayscale display, contrast resolution, and overall tissue texture, which cannot be evaluated with the anechoic, non-attenuating AIUM 100mm test object.

Question 101: A pulsed sound wave is best described by the following acoustic parameter:

Duty factor (Correct answer)
Period
Propagation speed
Frequency

Correct answer: Duty factor

The duty factor is the fraction of time that the pulsed ultrasound system is actively transmitting sound. It is a dimensionless number representing the ratio of pulse duration to the pulse repetition period. Since a pulsed wave involves intermittent periods of transmission and listening, the duty factor is a key acoustic parameter that specifically characterizes its intermittent nature.

Question 102: Which statement about dynamic receive focusing is correct?

It transmits multiple focal beams simultaneously
It is the same as transmit focusing
It adjusts the receive focus continuously as echoes return from increasing depths (Correct answer)
It only applies to elevation focusing

Correct answer: It adjusts the receive focus continuously as echoes return from increasing depths

Dynamic receive focusing updates the receive delays in real time so the system is always focused at the depth from which echoes are currently arriving.

Question 103: Which structure absorbs the most ultrasound energy per unit length and therefore poses the greatest risk of localized heating?

Fatty tissue
Blood within cardiac chambers
Cortical bone (Correct answer)
Amniotic fluid

Correct answer: Cortical bone

Cortical bone has a very high attenuation coefficient (absorption >> soft tissue), causing disproportionate energy absorption and localized heating at the bone surface.

Question 104: What is the half-value layer (HVL) in ultrasound attenuation?

The layer of tissue that reflects half the beam
The transducer depth at half-power output
The frequency at which attenuation doubles
The depth at which intensity is reduced by 50% (Correct answer)

Correct answer: The depth at which intensity is reduced by 50%

The half-value layer is the tissue depth at which the beam's intensity is reduced to half its original value.

Question 105: Which of the following best defines 'insonation angle' in Doppler ultrasound?

The angle between the ultrasound beam axis and the direction of blood flow (Correct answer)
The angle of the spectral display baseline
The angle of the sample volume gate relative to the vessel wall
The angle between two transducer crystals in a CW probe

Correct answer: The angle between the ultrasound beam axis and the direction of blood flow

The insonation angle (also called the Doppler angle or angle of incidence) is the angle between the ultrasound beam and the direction of blood flow, which must be known for accurate velocity calculation.

Question 106: Which color Doppler parameter directly controls the number of pulses used to estimate each color pixel?

Wall filter
Color priority
Ensemble length (packet size) (Correct answer)
Color gain

Correct answer: Ensemble length (packet size)

Ensemble length (packet size) is the number of pulses per scan line used for color velocity estimation; more pulses improve sensitivity but reduce frame rate.

Question 107: In digital ultrasound imaging, bit depth refers to:

The maximum imaging depth in centimeters
The lateral width of the scan plane
The number of bits used to encode the gray-scale value of each pixel (Correct answer)
The number of image frames stored per second

Correct answer: The number of bits used to encode the gray-scale value of each pixel

Bit depth determines how many distinct gray levels can be represented; 8-bit depth yields 256 gray levels.

Question 108: The spatial pulse length of a transducer is determined by the number of cycles in a pulse multiplied by the:

Pulse repetition period
Wavelength
Propagation speed divided by frequency
Both B and C (they are equivalent) (Correct answer)

Correct answer: Both B and C (they are equivalent)

Wavelength equals propagation speed divided by frequency, so spatial pulse length = number of cycles × wavelength = number of cycles × (speed/frequency).

Question 109: Which effect describes the heating of tissue caused by the absorption of ultrasound energy?

Piezoelectric effect
Cavitation
Doppler shift
Thermal bioeffect (Correct answer)

Correct answer: Thermal bioeffect

Thermal bioeffects occur when absorbed ultrasound energy is converted to heat within tissue.

Question 110: Increasing the dynamic range setting on the ultrasound unit will:

Increase the transmit power to deeper structures
Narrow the range of displayed gray levels
Display more gray shades, producing a softer-appearing image (Correct answer)
Produce a higher contrast image with fewer gray shades

Correct answer: Display more gray shades, producing a softer-appearing image

A wider displayed dynamic range maps more levels of echo amplitude into the gray scale, resulting in more subtle gray-scale gradations and a lower-contrast appearance.

Question 111: At the near field (Fresnel zone) boundary, the beam diameter is approximately:

Twice the transducer diameter
Equal to the transducer radius
Equal to the wavelength
Half the transducer diameter (Correct answer)

Correct answer: Half the transducer diameter

At the last axial maximum (near-field/far-field boundary), the beam width is approximately half the transducer diameter.

ARDMS SPI (Sonography Principles & Instrumentation) Exam

The ARDMS SPI (Sonography Principles & Instrumentation) Exam exam validates essential knowledge and skills required for certification or licensure in this field.

110

Questions

120 min

Time Limit

70%

To Pass

Checking for saved progress...

Exam Rules

You can skip questions and return to them later
Flag questions for review before submitting
No feedback shown until you submit the entire exam
Unanswered questions count as wrong — answer everything
10 pretest questions are mixed in and don't affect your score
Timer auto-submits when time runs out
Your progress is auto-saved every 30 seconds