WorksheetsUUP ch4
Total questions: 43
Worksheet time: 26mins
what are the 5 parameters to describe pulsed sound?
-period
-frequency
-amplitude
-power
-intensity
-pulse repetition frequency
-pulse duration
-pulse repetition period
-duty factor
-spatial pulse length
all of the above
what is pulsed sound?
a pulse of ultrasound is a collection of cycles that travel together.
a pulse of ultrasound is one singular cycle
a repetitive cycle
what are the two components of a pulse?
talking,
transmit,
"on" (time)
receive,
listening,
"off"(time)
loud,
long,
"off"(time)
what is pluse duration? and what are its units?
its the length of a cycle
units of time
microseconds
(μs)
actual time from the start of a pulse to the end of that pulse
units of length
centimeters
(cm)
what is pulsed duration determined by? is it adjustable?
determined by sound source ONLY
determined by medium
ONLY
it can be adjusted by the sonographer
Can't be adjusted
(each transducer has its own fixed duration)
what are the characteristics of a long duration
many cycles in the pulse
individual cycles with long periods
few cycles in the pulse
individual cycles with short periods
what are the characteristics of a short duration pulse?
few cycles in the pulse
individual cycles with long periods
many cycles in the pulse
individual cycles with long periods
how is pulse duration related to the number of cycles in the pulse ?
directly related
when one goes up the other goes up
inversely related when one goes down the other goes up
not related
they dont connect at all
how is pulse duration related to period
directly related
when one goes up the other goes up
inversely related when one goes up the other goes down
not related
how is pulse duration related to frequency
directly related
when one goes up the other goes up
inversely related when one goes down the other goes up
not related
what is spatial pulse length? and what are its units?
the DISTANCE that a pulse occupies in space from the start to the end
the TIME that a pulse takes from start to finish
units of time
microseconds
units of distance
millimeters
(mm)
what is spatial pulse length determined by ? is it adjustable ?
the sound source AND the medium
just the medium
it is adjustable by a knob on the machine
it is not adjustable
spatial pulse length = #cycles x wavelength
what's the relationship between spatial pulse length and the number of cycles
directly proportional
when one goes up the other one as well
inversely proportional
when one goes up the other one goes down
not related
spatial pulse length = #cycles x wavelength
what is the relationship between spatial pulse length and wavelength ?
directly proportional
when one goes up the other goes up
inversely proportional when one goes up the other goes down
not related
how is spatial pulse length related to frequency?
directly related
when one goes up the other goes up
inversely related when one goes down the other goes up
not related
which type of pulse lengths is more desirable long or short?
shorter lengths are desirable because it creates more accurate images
longer lengths are desirable because it creates bigger images
what is pulse repetition period and what are its units
PRP is the time it takes from the start of one pulse to the start of the next one
PRP is the length of the pulse from the start of one pulse to the start of the next one
reported in units of time
microseconds
reported in units of distance such as mm
what is PRP determined by and is it adjustable?
sound source ONLY
BOTH sound source and medium
no it is not adjustable
yes it can be adjusted by altering the depth of the image
How is Pulse repetition period related to imagine depth ?
dirrectly related
inversely related
not related
what are the two components of PRP?
on time
Transmit time
off time
receiving time
late time
transmit time
does a deep image have a longer PRP or a shorter PRP
longer PRP
shorter pop
does a shallow image have a shorter pulse repitition period or a longer PRP
short PRP
long PRP
what is pulse repitition frequency and what are its units?
the number of pulses that an ultrasound system transmits into the body each second
the length of the a cycle from the start to the start of the next one
its measured in units of time
microseconds
its measured in Hertz aka (per second)
what is PRF determined by? and is it adjustable
determined by the sound source only
determined by the medium only
it is not adjustable
it is adjustable by adjusting the depth in the image
how is pulse repitition frequency related to depth of an image?
directly related when one goes up the other goes up
inversely related when one goes down the other goes up
not related
an ultrasound machine is imagine to a depth of 2cm, would the pulse repetition frequency be described as high or low?
it would be high because they're inversely related
it would be low because theyre directly related
if the monographer adjusts the machine to 20cm depth, what would happen to the PRF ?
the pro would be high because theyre directly related
the PRF would be low because theyre inversely related
what is the relationship of PRP and PRF
theyre directly related
theyre inversely related
theyre not related
PRF and PRP are reciprocals therefore select all that are correct
PRP= 1/PRF
PRF= 1/PRP
PRF=PRP
1=PRP x PRF
which of these four values for PRF would have the longest PRP
2kHZ
4000Hz
6Hz
1kHz
of the four pulse repitition periods which would have the highest frequency
8s
80ms
5ms
400ks
True or false is PRF and PRP determined by imaging depth
true
false
what is duty factor and what are its units
the time it takes for a pulse to form
the percentage or fraction of time that the system transmits a pulse
its measured in Hz
it has no units
what is duty factor determined by ? is it adjustable?
determined by the sound source
determined by the medium
no its not adjustable
yes it is by changing the depth of view
how is duty factor and depth of view related?
directly proportional
inversely proportional
not related
Dutch factor(%) = (pulse duration/ PRP) x 100
this is the equation remember it !!!!!
remember it
forget it
switch it up
what is the maximum and minimum values for duty factor
1%-100%
0%-100%
1%-99%
1%-110%
if a machine has a duty factor of .2 it indicates it was transmitting .2% of the time, what percent of time was it receiving?
98%
99.8%
92%
98.8%
for an image to actually be produced a duty factor less than
100%
1%
98%
10%
if all other factors are unchanged what happens to duty factor when PRF increases
increases
decreases
remains the same
if all other factors remain unchanged what happens to duty factor when imagine depth increases
increases
decreases
remains the same
what is the duty factor if the pulse duration is 1μs and the pulse repitition frequency is 1ms
100%
.1
.01
.001
the speed of a 5MHz continuous wave is 1.8km/sec. the wave is then pulsed with a duty factor of .5 calculate the new propagation speed
36km/sec
1.8km/sec
18km/sec
.18km/sec
