ARDMS SPI STUDY GUIDE
QUESTIONS & ANSWERS PASSED
ALREADY GRADED A+
In soft tissue, if the frequency of a wave is increased the Propagation Speed (PS) will... -
CORRECT ANSWER Remain the Same because stiffness and density affect Propagation Speed.
What is the audible range? - CORRECT ANSWER 20-20,000Hz
>20,000Hz=Ultrasound
Frequency is measured in - CORRECT ANSWER Hertz (Hz)
is
Cycles per Second
Not affected by sonographer
Increase Frequency; Decrease Depth
A period is the length of time it takes for - CORRECT ANSWER one complete wavelength to pass
a fixed point
PRP is determined by - CORRECT ANSWER Transmit time and receive time.
Period is measured in - CORRECT ANSWER Time (μs)
,When the sonographer changes the imaging depth what parameters are changed? - CORRECT
ANSWER PRP, PRF, Duty Factor
What is duty factor? - CORRECT ANSWER The percentage or fraction of time that the system is
transmitting a pulse (Time Sound is ON or ON-Time).
Propagation Speed in SOFT TISSUE - CORRECT ANSWER 1.54 mm/μs
(1540 m/sec)
Unit of measurement for Pulse Duration, Duty Factor, PRP, and Period - CORRECT ANSWER
Time, (μs)
Pulse duration is determined by - CORRECT ANSWER Sound Source Only
Pulse Duration is controlled by - CORRECT ANSWER the ultrasound system and transducer
Pulse Duration Formula - CORRECT ANSWER pulse duration (μs) = # cycles in
pulse/frequency(MHz)
PD= Number of cycles in Pulse/ Frequency(Hz)
Spatial Pulse Length (SPL) (measurement) - CORRECT ANSWER The distance that a pulse
occupies in space from the start to the end of a pulse.
(mm)
Typical values for spatial pulse length in soft tissue. - CORRECT ANSWER 0.1 to 1.0 mm
, Spatial pulse length is determined by - CORRECT ANSWER sound source and medium
Spatial Pulse Length is directly proportional to - CORRECT ANSWER the Number of Cycles in the
Pulse
and
the Wavelength
(Directly Proportional means that increased SPL will increase both the number of cycles in the
pulse and the wavelength if increased).
Spatial pulse length is inversely proportional to - CORRECT ANSWER Frequency (MHz)
(Inversely Proportional means that increased SPL will lower frequency. This is because axial
resolution is better with lower frequency)
Pulse Duration (PD) - CORRECT ANSWER The actual time from the start of a pulse to the end of
that pulse; a single transmit, talking, or "on" time.
Time the pulse is on typically measured in (ms).
Pulse Length - CORRECT ANSWER The distance of the pulse start to end or the
duration or length of a single pulse
Pulse Length is typically measured in (mm).
the ability of an object to resist compression and relates to the hardness of a medium? -
CORRECT ANSWER Stiffness.
Think:
↑ Stiffness ↑ Speed
QUESTIONS & ANSWERS PASSED
ALREADY GRADED A+
In soft tissue, if the frequency of a wave is increased the Propagation Speed (PS) will... -
CORRECT ANSWER Remain the Same because stiffness and density affect Propagation Speed.
What is the audible range? - CORRECT ANSWER 20-20,000Hz
>20,000Hz=Ultrasound
Frequency is measured in - CORRECT ANSWER Hertz (Hz)
is
Cycles per Second
Not affected by sonographer
Increase Frequency; Decrease Depth
A period is the length of time it takes for - CORRECT ANSWER one complete wavelength to pass
a fixed point
PRP is determined by - CORRECT ANSWER Transmit time and receive time.
Period is measured in - CORRECT ANSWER Time (μs)
,When the sonographer changes the imaging depth what parameters are changed? - CORRECT
ANSWER PRP, PRF, Duty Factor
What is duty factor? - CORRECT ANSWER The percentage or fraction of time that the system is
transmitting a pulse (Time Sound is ON or ON-Time).
Propagation Speed in SOFT TISSUE - CORRECT ANSWER 1.54 mm/μs
(1540 m/sec)
Unit of measurement for Pulse Duration, Duty Factor, PRP, and Period - CORRECT ANSWER
Time, (μs)
Pulse duration is determined by - CORRECT ANSWER Sound Source Only
Pulse Duration is controlled by - CORRECT ANSWER the ultrasound system and transducer
Pulse Duration Formula - CORRECT ANSWER pulse duration (μs) = # cycles in
pulse/frequency(MHz)
PD= Number of cycles in Pulse/ Frequency(Hz)
Spatial Pulse Length (SPL) (measurement) - CORRECT ANSWER The distance that a pulse
occupies in space from the start to the end of a pulse.
(mm)
Typical values for spatial pulse length in soft tissue. - CORRECT ANSWER 0.1 to 1.0 mm
, Spatial pulse length is determined by - CORRECT ANSWER sound source and medium
Spatial Pulse Length is directly proportional to - CORRECT ANSWER the Number of Cycles in the
Pulse
and
the Wavelength
(Directly Proportional means that increased SPL will increase both the number of cycles in the
pulse and the wavelength if increased).
Spatial pulse length is inversely proportional to - CORRECT ANSWER Frequency (MHz)
(Inversely Proportional means that increased SPL will lower frequency. This is because axial
resolution is better with lower frequency)
Pulse Duration (PD) - CORRECT ANSWER The actual time from the start of a pulse to the end of
that pulse; a single transmit, talking, or "on" time.
Time the pulse is on typically measured in (ms).
Pulse Length - CORRECT ANSWER The distance of the pulse start to end or the
duration or length of a single pulse
Pulse Length is typically measured in (mm).
the ability of an object to resist compression and relates to the hardness of a medium? -
CORRECT ANSWER Stiffness.
Think:
↑ Stiffness ↑ Speed
