2024 ARDMS SPI STUDY GUIDE QUESTIONS AND ANSWERS LATEST UPDATE | ALREADY PASSED 100%

2024 ARDMS SPI STUDY GUIDE QUESTIONS AND
ANSWERS LATEST UPDATE | ALREADY PASSED
100%
In soft tissue, if the frequency of a wave is
increased the Propagation Speed (PS) will... -
✔✔✔✔Remain the Same because stiffness and
density affect Propagation Speed.
What is the audible range? - ✔✔✔✔20-20,000Hz
>20,000Hz=Ultrasound
Frequency is measured in - ✔✔✔✔Hertz (Hz)
is
Cycles per Second
Not affected by sonographer
Increase Frequency; Decrease Depth
A period is the length of time it takes for -
✔✔✔✔one complete wavelength to pass a fixed
point
PRP is determined by - ✔✔✔✔Transmit time and
receive time.
Period is measured in - ✔✔✔✔Time (μs)
When the sonographer changes the imaging depth
what parameters are changed? - ✔✔✔✔PRP, PRF,
Duty Factor
What is duty factor? - ✔✔✔✔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 - ✔✔✔✔1.54
mm/μs
(1540 m/sec)
Unit of measurement for Pulse Duration, Duty
Factor, PRP, and Period - ✔✔✔✔Time, (μs)
Pulse duration is determined by - ✔✔✔✔Sound
Source Only
Pulse Duration is controlled by - ✔✔✔✔the
ultrasound system and transducer
Pulse Duration Formula - ✔✔✔✔pulse duration
(μs) = # cycles in pulse/frequency(MHz)
PD= Number of cycles in Pulse/ Frequency(Hz)
Spatial Pulse Length (SPL) (measurement) -
✔✔✔✔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.
- ✔✔✔✔0.1 to 1.0 mm
Spatial pulse length is determined by -
✔✔✔✔sound source and medium
Spatial Pulse Length is directly proportional to -
✔✔✔✔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 -
✔✔✔✔Frequency (MHz)
(Inversely Proportional means that increased SPL
will lower frequency. This is because axial
resolution is better with lower frequency)
Pulse Duration (PD) - ✔✔✔✔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 - ✔✔✔✔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? -
✔✔✔✔Stiffness.
Think:
↑ Stiffness ↑ Speed
↓ Density ↑ Speed
An increase in pulse repetition frequency would
lead to: - ✔✔✔✔Increasing pulse repetition
frequency, increases duty factor.
↑ PRF ↑ Duty Facto