Chapter 4 and 5 quiz Flashcards
Rank these intensities from largest to smallest:
SPTS, SPPA, SPTA, SATP, SAPA, SATA
SPTA is important regarding __________
Tissue heating
Does an ultrasound beam have the same intensity at different locations?
No
Deeper images creates ___________ listening, _________ PRP, _______ PRF, and ___________ duty factor.
What is the minimum value for duty factor?
0%
PRP and PRF are _______ related.
Inversely
An ultrasound machine is imaging to a depth of 2 cm. Would the PRF be describes as high or low?
High
How can a sonographer change the PRP?
Depth control
Spatial pulse length is determined by ___________
Sound source and medium
What characteristics create a long pulse duration?
Many cycles in a period or wavelength
Which of these four values for PRF would have the longest PRP? 2 kHz 4000 Hz 6 Hz 1 kHz
6 Hz
A sound beam travels a total of 10 cm in 2 seconds. What is the speed of the sound?
5 cm/sec
What is the wavelength of a wave with an unknown frequency traveling in soft tissue?
0.51 mm
By changing the imaging depth, which of the following does the operator also change ….
PRF, duty factor, and PRP
Ultrasound is defined as a sound with a frequency of _________
Greater than 0.02 MHz
Which of the following cannot be considered a unit of frequency?
Cycles
What are the units of pulse duration?
Units of time (sec, years, etc)
What determines the pulse duration?
The soundsource
Two pulses are created by different transducers. The pulses have different durations. Which pulse is likely to create the best image?
The shorter duration pulse
Using a specific transducer, what happens to the spatial pulse length at the sonographer increases the maximum imaging depth?
Which of the following is a correct description of PRP?
The sum of the pulse’s “on” time and listening “off” time
In diagnostic imaging, what determines the Spatial pulse length?
What are the units of PRF?
In diagnostic imaging, what establishes the PRF?
The source of the sound
What is the value of the duty cycle for continuous wave ultrasound? 100 1% 1000% none of the above
None of the above
The PRF is the _____
what is the importance of describing sound beam intensities in a variety of ways with regard to space and time?
It’s important when studying bioeffects
Which intensity is most closely correlated to tissue heating?
SPTA
