SPI EXAM REVIEW QUESTIONS &
VALID ANSWERS RATED 100%
CORRECT
ultrasound imaging type in which pulses are reflected and used to produce a display CORRECT
ANSWER - pulsed wave
brightness of the dots on image CORRECT ANSWER - amplitude
round-trip travel time per cm in soft tissue CORRECT ANSWER - 13 microseconds
A line produced on a display that represents ultrasonic echoes returning from the body. A
sonographic image is composed of many such lines. CORRECT ANSWER - scan line
Type of image presented in a rectangular format.
- Each pulse travels in same direction
- Different starting point for each pulse
- Yields series of parallel scan lines CORRECT ANSWER - linear
Type of image presented in a pie-slice or wedge shaped format.
- Each pulse originates from the same starting point
- Subsequent pulses go out in different directions from previous ones CORRECT ANSWER -
sector
Frequency change tracking caused by motion of reflectors towards or away from the transducer
- Used extensively in vascular & cardiac ultrasound CORRECT ANSWER - Doppler Shift
,The presentation of two-dimensional, real-time Doppler-shift information superimposed on a
real-time, gray-scale, anatomic, cross-sectional image. Flow directions toward and away from
the transducer (i.e., positive & negative Doppler shifts) are presented as different colors on the
display. CORRECT ANSWER - Color Doppler
Unit of power or intensity ratio; also a unit of amplitude ratio CORRECT ANSWER - decibel
doubled intensity in dB CORRECT ANSWER - 3 dB
mathematical numerical system in which the number of 10s that are multiplied together in
order to equal the number
Log₁₀ of 100 = 10 × 10 = 100 or 10²
Log₁₀ of 100 = 2 CORRECT ANSWER - logarithm
What transports energy, not matter? CORRECT ANSWER - wave
Type of sound wave that requires a medium to travel in and, therefore, cannot propagate in a
vacuum. CORRECT ANSWER - mechanical
Regions of high density and pressure in a compressional wave. CORRECT ANSWER -
compression
Region of low density and pressure in a compressional wave. CORRECT ANSWER - rarefaction
What are the 3 acoustic variables? List them alphabetically. CORRECT ANSWER - density,
distance, pressure
,Concentration of force
- Units: pascals (Pa), lbs/in², atmospheres CORRECT ANSWER - Pressure
Concentration of mass
- Units: kilo/cm³ CORRECT ANSWER - Density
cycles per second CORRECT ANSWER - frequency
unit of frequency, one cycle per second CORRECT ANSWER - hertz
20 → 20,000 Hz (20 kHz) CORRECT ANSWER - audible sound
2 to 15 MHz CORRECT ANSWER - What is the useful diagnostic frequency range for ultrasound
in humans?
time per cycle
- Equation: If T = period in microseconds (µs) and ƒ = frequency in megahertz (MHz), then
T (µs) = 1/ƒ (Mhz)
- Reciprocal of frequency equation CORRECT ANSWER - period
As frequency increases, period _________. CORRECT ANSWER - decreases
length of space over which a cycle occurs
- Abbreviated: λ (lambda) CORRECT ANSWER - wavelength
, 0.1 → 0.8 mm CORRECT ANSWER - What is the typical ultrasound wavelength range?
speed with which a wave moves through a medium
Units: mm/μs, m/s
Abbreviation: c CORRECT ANSWER - propagation speed
What two properties of a medium affect its propagation speed? CORRECT ANSWER - density,
stiffness
1.54 mm/μs OR 1540 m/s CORRECT ANSWER - speed of sound in soft tissue
Order the following by propagation speed from slowest to fastest:
bone, fat, air, muscle, liver CORRECT ANSWER - air, fat, liver, muscle, bone
the resistance that sound encounters in traveling through a medium CORRECT ANSWER -
impedance
unit of impedance CORRECT ANSWER - Rayl
equation that illustrates relationship between round-trip pulse travel time, propagation speed,
and distance to the reflector CORRECT ANSWER - range equation
(PW) the number of pulses that occur in 1 sec; sometimes called pulse repetition rate CORRECT
ANSWER - pulse repetition frequency
When distance (depth) increases, PRF ---------. CORRECT ANSWER - decreases
VALID ANSWERS RATED 100%
CORRECT
ultrasound imaging type in which pulses are reflected and used to produce a display CORRECT
ANSWER - pulsed wave
brightness of the dots on image CORRECT ANSWER - amplitude
round-trip travel time per cm in soft tissue CORRECT ANSWER - 13 microseconds
A line produced on a display that represents ultrasonic echoes returning from the body. A
sonographic image is composed of many such lines. CORRECT ANSWER - scan line
Type of image presented in a rectangular format.
- Each pulse travels in same direction
- Different starting point for each pulse
- Yields series of parallel scan lines CORRECT ANSWER - linear
Type of image presented in a pie-slice or wedge shaped format.
- Each pulse originates from the same starting point
- Subsequent pulses go out in different directions from previous ones CORRECT ANSWER -
sector
Frequency change tracking caused by motion of reflectors towards or away from the transducer
- Used extensively in vascular & cardiac ultrasound CORRECT ANSWER - Doppler Shift
,The presentation of two-dimensional, real-time Doppler-shift information superimposed on a
real-time, gray-scale, anatomic, cross-sectional image. Flow directions toward and away from
the transducer (i.e., positive & negative Doppler shifts) are presented as different colors on the
display. CORRECT ANSWER - Color Doppler
Unit of power or intensity ratio; also a unit of amplitude ratio CORRECT ANSWER - decibel
doubled intensity in dB CORRECT ANSWER - 3 dB
mathematical numerical system in which the number of 10s that are multiplied together in
order to equal the number
Log₁₀ of 100 = 10 × 10 = 100 or 10²
Log₁₀ of 100 = 2 CORRECT ANSWER - logarithm
What transports energy, not matter? CORRECT ANSWER - wave
Type of sound wave that requires a medium to travel in and, therefore, cannot propagate in a
vacuum. CORRECT ANSWER - mechanical
Regions of high density and pressure in a compressional wave. CORRECT ANSWER -
compression
Region of low density and pressure in a compressional wave. CORRECT ANSWER - rarefaction
What are the 3 acoustic variables? List them alphabetically. CORRECT ANSWER - density,
distance, pressure
,Concentration of force
- Units: pascals (Pa), lbs/in², atmospheres CORRECT ANSWER - Pressure
Concentration of mass
- Units: kilo/cm³ CORRECT ANSWER - Density
cycles per second CORRECT ANSWER - frequency
unit of frequency, one cycle per second CORRECT ANSWER - hertz
20 → 20,000 Hz (20 kHz) CORRECT ANSWER - audible sound
2 to 15 MHz CORRECT ANSWER - What is the useful diagnostic frequency range for ultrasound
in humans?
time per cycle
- Equation: If T = period in microseconds (µs) and ƒ = frequency in megahertz (MHz), then
T (µs) = 1/ƒ (Mhz)
- Reciprocal of frequency equation CORRECT ANSWER - period
As frequency increases, period _________. CORRECT ANSWER - decreases
length of space over which a cycle occurs
- Abbreviated: λ (lambda) CORRECT ANSWER - wavelength
, 0.1 → 0.8 mm CORRECT ANSWER - What is the typical ultrasound wavelength range?
speed with which a wave moves through a medium
Units: mm/μs, m/s
Abbreviation: c CORRECT ANSWER - propagation speed
What two properties of a medium affect its propagation speed? CORRECT ANSWER - density,
stiffness
1.54 mm/μs OR 1540 m/s CORRECT ANSWER - speed of sound in soft tissue
Order the following by propagation speed from slowest to fastest:
bone, fat, air, muscle, liver CORRECT ANSWER - air, fat, liver, muscle, bone
the resistance that sound encounters in traveling through a medium CORRECT ANSWER -
impedance
unit of impedance CORRECT ANSWER - Rayl
equation that illustrates relationship between round-trip pulse travel time, propagation speed,
and distance to the reflector CORRECT ANSWER - range equation
(PW) the number of pulses that occur in 1 sec; sometimes called pulse repetition rate CORRECT
ANSWER - pulse repetition frequency
When distance (depth) increases, PRF ---------. CORRECT ANSWER - decreases
