SPI EXAM REVIEW 2026/2027
ACTUAL QUESTIONS WITH VERIFIED
ANSWERS.
What are some reasons for color aliasing? - correct answer--
high velocities
- color scale setting too low
Variance - correct answer-square of standard deviation; one of
the outputs of the autocorrelation process; a measure of
spectral broadening (i.e., spread around the mean)
Variance map - correct answer-- another color added (usually
green)
- with increase in variance, brightness of green increases
- color green signifies disturbed/turbulent flow
- used in cardiac imaging (echocardiography)
Color components - correct answer-Hue - color that eye
perceives
,Saturation - amount to which the original color is diluted with
white
Luminance - the brightness of hue and saturation of the color
Autocorrelation - correct answer-a rapid technique, used in
most color Doppler instruments for obtaining mean Doppler-
shift frequency
- similar to FFT, but faster
Time domain processing - correct answer-newer method of
Doppler shift analysis
- faster than FFT/Autocorrelation
- can pinpoint specific echo out of many
Doppler-power display (Doppler Power) - correct answer-color
Doppler display in which colors are assigned according to the
strength (amplitude, power, intensity, energy) of the Doppler-
shifted echoes
- no velocities at all
- relates to RBC concentration
,Power Doppler advantages / disadvantages - correct answer-
Advantages:
- not angle dependent
- not subject to aliasing
- greater sensitivity to flow (low velocities)
Disadvantages:
- not direction sensitive
- cannot detect velocity
- cannot detect flow characteristics
- takes more time
- flash artifact possible
Doppler spectrum - correct answer-The range of frequencies
present in Doppler shifted echoes
Duplex instrument - correct answer-An ultrasound instrument
that combines gray-scale sonography with pulsed Doppler, and
possibly continuous-wave Doppler
Continuous-wave - correct answer-A wave in which cycles
repeat indefinitely; not pulsed
Abbreviation: CW
, Baseline shift - correct answer-Movement of the zero Doppler-
shift frequency or zero flow speed line up or down on a spectral
display
Doppler angle - correct answer-The angle between the sound
beam and flow direction.
Should be between 45° and 60° for optimum accuracy of
velocities
Artifact - correct answer-anything appearing on the display that
does not represent real echo information
Reasons for artifacts - correct answer-1) physical laws of
ultrasound are broken
2) misinterpretation of image information
3) ultrasound machine's failure to perform
4) failure to operate equipment properly
5) physical nature of sound
ACTUAL QUESTIONS WITH VERIFIED
ANSWERS.
What are some reasons for color aliasing? - correct answer--
high velocities
- color scale setting too low
Variance - correct answer-square of standard deviation; one of
the outputs of the autocorrelation process; a measure of
spectral broadening (i.e., spread around the mean)
Variance map - correct answer-- another color added (usually
green)
- with increase in variance, brightness of green increases
- color green signifies disturbed/turbulent flow
- used in cardiac imaging (echocardiography)
Color components - correct answer-Hue - color that eye
perceives
,Saturation - amount to which the original color is diluted with
white
Luminance - the brightness of hue and saturation of the color
Autocorrelation - correct answer-a rapid technique, used in
most color Doppler instruments for obtaining mean Doppler-
shift frequency
- similar to FFT, but faster
Time domain processing - correct answer-newer method of
Doppler shift analysis
- faster than FFT/Autocorrelation
- can pinpoint specific echo out of many
Doppler-power display (Doppler Power) - correct answer-color
Doppler display in which colors are assigned according to the
strength (amplitude, power, intensity, energy) of the Doppler-
shifted echoes
- no velocities at all
- relates to RBC concentration
,Power Doppler advantages / disadvantages - correct answer-
Advantages:
- not angle dependent
- not subject to aliasing
- greater sensitivity to flow (low velocities)
Disadvantages:
- not direction sensitive
- cannot detect velocity
- cannot detect flow characteristics
- takes more time
- flash artifact possible
Doppler spectrum - correct answer-The range of frequencies
present in Doppler shifted echoes
Duplex instrument - correct answer-An ultrasound instrument
that combines gray-scale sonography with pulsed Doppler, and
possibly continuous-wave Doppler
Continuous-wave - correct answer-A wave in which cycles
repeat indefinitely; not pulsed
Abbreviation: CW
, Baseline shift - correct answer-Movement of the zero Doppler-
shift frequency or zero flow speed line up or down on a spectral
display
Doppler angle - correct answer-The angle between the sound
beam and flow direction.
Should be between 45° and 60° for optimum accuracy of
velocities
Artifact - correct answer-anything appearing on the display that
does not represent real echo information
Reasons for artifacts - correct answer-1) physical laws of
ultrasound are broken
2) misinterpretation of image information
3) ultrasound machine's failure to perform
4) failure to operate equipment properly
5) physical nature of sound
