ARDMS SPI EXAM FINAL WITH 150 QUESTIONS AND
CORRECT ANSWERS 2025/2026
This image was obtained with a linear array transducer. The trapezoidal field of view increases
the field of view. How is the trapezoidal shape created?
See image for question #244
A. Electronic beam steering
B. Side lobes
C. Grating lobes
D. Mechanically steering the elements
E. Mirror CORRECT ANSWERS: A. Electronic beam steering
<A trapezoidal image can be obtained with a linear array transducer by electronically steering the
beam>
What advantage is related to the use of a tightly curved array transducer?
A. Axial resolution is improved
B. Lateral resolution is improved
,C. Field of view is improved
D. Temporal resolution is improved
E. Elevational resolution is improved CORRECT ANSWERS: C. Field of view is improved
When you increase the scan line density in the B-mode image, you improve:
A. Temporal resolution
B. Contrast resolution
C. Slice thickness
D. Axial resolution
E. Lateral resolution CORRECT ANSWERS: E. Lateral resolution
<Lateral resolution decreases when the distance between vectors (lines of sight) is greater than
the beam width>
The image on the left demonstrates poor lateral resolution compared to the image on the right.
How were the system controls adjusted to optimize the image on the right?
See image for question #207
A. Increased dynamic range
B. Decreased transducer frequency
C. Changed gray map
D. Increased line density
E. Reduced frame averaging CORRECT ANSWERS: D. Increased line density
<The image on the left shows lateral smearing of the echoes. This is the result of poor lateral
resolution. With the increase in line density, lateral resolution is improved in the image on the
right>
Spatial pulse length is equal to:
A. The wavelength times the number of cycles in the pulse
B. The wavelength minus the number of cycles in the pulse
C. The wavelength times the axial resolution
D. The wavelength times the beam width
E. The wavelength divided by 2 CORRECT ANSWERS: A. The wavelength times the number
of cycles in the pulse
<It is more common for engineers to specify the pulse duration. Then spatial pulse length is
equal to the pulse duration times the speed of sound>
,With a standard one-dimensional linear array transducer, what type of resolution is affected most
by electronic focusing and dynamic aperture?
A. Lateral resolution
B. Contrast resolution
C. Temporal resolution
D. Axial resolution
E. Elevational resolution CORRECT ANSWERS: A. Lateral resolution
<Lateral resolution is improved at depth by increasing transducer width or aperture size in an
array. Essentially, the larger the aperture (the active portion of the array), the smaller the beam
width at the local point>
The transducer you are using is an array assembly. What is an advantage of this type of
transducer?
A. Transducer arrays produce pure, single-frequency beams
B. Transducer arrays enable mechanical steering
C. Transducer arrays produce very long pulses for improved axial resolution
D. Transducer arrays have greater dynamic range, resulting in more displayed shades of gray
E. Transducer arrays enable electronic focusing and steering CORRECT ANSWERS: E.
Transducer arrays enable electronic focusing and steering
<Transducer arrays use multiple elements rather than a single element to form the beam. With
delayed transmit firing times to the elements, both focusing and beam steering can be
accomplished electronically. This allows a sector shape to be present without the necessity of
moving parts (as in a mechanically steered transducer). Also, multiple points of focus can be
achieved electronically, whereas with single element transducers focus the beam mechanically
by curving the element, applying a lens or using a curved mirror>
Dynamic apodization is a method employed to:
A. Focus the beam at multiple depths on transmit
B. Focus the beam at multiple depths on receive
C. Reduce side lobes
D. Reduce beam width in the z-axis
E. Steer the beam CORRECT ANSWERS: C. Reduce side lobes
, <Side lobes are part of the beam pattern from any transducer. They are transmitted into the tissue
at various angles with respect to the main beam and can result in significant artifacts in the
ultrasound image. Use of broad-bandwidth pulses reduces their strength. With array transducers,
maximizing the excitation voltage for elements near the center of the beam and reducing it
towards the periphery can reduce side lobes. This variation in excitation strength to the array
elements is termed apodization>
Which statement is NOT true regarding lateral resolution?
A. It is equal to beam width
B. It is improved by focusing
C. It is defined as the minimum separation required to resolve two structures perpendicular to the
beam axis
D. It is also known as azimuthal resolution
E. It remains constant throughout scanning depth CORRECT ANSWERS: E. It remains
constant throughout scanning depth
<Lateral resolution varies with depth. It is best at the focal point and degrades on either side>
Which of the following minimizes the degree to which beam width varies with depth?
A. Apodization
B. Dynamic aperture
C. Coprocessing
D. Rectification
E. Frame averaging (persistence) CORRECT ANSWERS: B. Dynamic aperture
<By varying the active aperture with depth, the beam width variation is reduced>
What type of transducer has the same measurement for elevational and lateral resolution?
A. Convex linear array
B. Phased linear array
C. Annular array
D. Sequential linear array
E. Mechanical sector CORRECT ANSWERS: C. Annular array
<An annular array transducer produces a beam that is symmetric about the beam axis. Therefore,
its lateral resolution is equal to its elevational (slice-thickness) resolution>
CORRECT ANSWERS 2025/2026
This image was obtained with a linear array transducer. The trapezoidal field of view increases
the field of view. How is the trapezoidal shape created?
See image for question #244
A. Electronic beam steering
B. Side lobes
C. Grating lobes
D. Mechanically steering the elements
E. Mirror CORRECT ANSWERS: A. Electronic beam steering
<A trapezoidal image can be obtained with a linear array transducer by electronically steering the
beam>
What advantage is related to the use of a tightly curved array transducer?
A. Axial resolution is improved
B. Lateral resolution is improved
,C. Field of view is improved
D. Temporal resolution is improved
E. Elevational resolution is improved CORRECT ANSWERS: C. Field of view is improved
When you increase the scan line density in the B-mode image, you improve:
A. Temporal resolution
B. Contrast resolution
C. Slice thickness
D. Axial resolution
E. Lateral resolution CORRECT ANSWERS: E. Lateral resolution
<Lateral resolution decreases when the distance between vectors (lines of sight) is greater than
the beam width>
The image on the left demonstrates poor lateral resolution compared to the image on the right.
How were the system controls adjusted to optimize the image on the right?
See image for question #207
A. Increased dynamic range
B. Decreased transducer frequency
C. Changed gray map
D. Increased line density
E. Reduced frame averaging CORRECT ANSWERS: D. Increased line density
<The image on the left shows lateral smearing of the echoes. This is the result of poor lateral
resolution. With the increase in line density, lateral resolution is improved in the image on the
right>
Spatial pulse length is equal to:
A. The wavelength times the number of cycles in the pulse
B. The wavelength minus the number of cycles in the pulse
C. The wavelength times the axial resolution
D. The wavelength times the beam width
E. The wavelength divided by 2 CORRECT ANSWERS: A. The wavelength times the number
of cycles in the pulse
<It is more common for engineers to specify the pulse duration. Then spatial pulse length is
equal to the pulse duration times the speed of sound>
,With a standard one-dimensional linear array transducer, what type of resolution is affected most
by electronic focusing and dynamic aperture?
A. Lateral resolution
B. Contrast resolution
C. Temporal resolution
D. Axial resolution
E. Elevational resolution CORRECT ANSWERS: A. Lateral resolution
<Lateral resolution is improved at depth by increasing transducer width or aperture size in an
array. Essentially, the larger the aperture (the active portion of the array), the smaller the beam
width at the local point>
The transducer you are using is an array assembly. What is an advantage of this type of
transducer?
A. Transducer arrays produce pure, single-frequency beams
B. Transducer arrays enable mechanical steering
C. Transducer arrays produce very long pulses for improved axial resolution
D. Transducer arrays have greater dynamic range, resulting in more displayed shades of gray
E. Transducer arrays enable electronic focusing and steering CORRECT ANSWERS: E.
Transducer arrays enable electronic focusing and steering
<Transducer arrays use multiple elements rather than a single element to form the beam. With
delayed transmit firing times to the elements, both focusing and beam steering can be
accomplished electronically. This allows a sector shape to be present without the necessity of
moving parts (as in a mechanically steered transducer). Also, multiple points of focus can be
achieved electronically, whereas with single element transducers focus the beam mechanically
by curving the element, applying a lens or using a curved mirror>
Dynamic apodization is a method employed to:
A. Focus the beam at multiple depths on transmit
B. Focus the beam at multiple depths on receive
C. Reduce side lobes
D. Reduce beam width in the z-axis
E. Steer the beam CORRECT ANSWERS: C. Reduce side lobes
, <Side lobes are part of the beam pattern from any transducer. They are transmitted into the tissue
at various angles with respect to the main beam and can result in significant artifacts in the
ultrasound image. Use of broad-bandwidth pulses reduces their strength. With array transducers,
maximizing the excitation voltage for elements near the center of the beam and reducing it
towards the periphery can reduce side lobes. This variation in excitation strength to the array
elements is termed apodization>
Which statement is NOT true regarding lateral resolution?
A. It is equal to beam width
B. It is improved by focusing
C. It is defined as the minimum separation required to resolve two structures perpendicular to the
beam axis
D. It is also known as azimuthal resolution
E. It remains constant throughout scanning depth CORRECT ANSWERS: E. It remains
constant throughout scanning depth
<Lateral resolution varies with depth. It is best at the focal point and degrades on either side>
Which of the following minimizes the degree to which beam width varies with depth?
A. Apodization
B. Dynamic aperture
C. Coprocessing
D. Rectification
E. Frame averaging (persistence) CORRECT ANSWERS: B. Dynamic aperture
<By varying the active aperture with depth, the beam width variation is reduced>
What type of transducer has the same measurement for elevational and lateral resolution?
A. Convex linear array
B. Phased linear array
C. Annular array
D. Sequential linear array
E. Mechanical sector CORRECT ANSWERS: C. Annular array
<An annular array transducer produces a beam that is symmetric about the beam axis. Therefore,
its lateral resolution is equal to its elevational (slice-thickness) resolution>
