Save
Busy. Please wait.
Log in with Clever
or
show password
Forgot Password?
Don't have an account?  Sign up 
Sign up using Clever
or
Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account. Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
focusNode
Didn't know it?
click below
 
Knew it?
click below
Don't Know
Remaining cards (0)
Know
0:00
edit
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Pulsed Waves

Chapter 4 in Edelman

QuestionAnswer
The 5 parameters that describe pulsed waves Pulse duration (PD), pulse repetition period (PRP), pulse repetition frequency (PRF), duty factor (DF) and spatial pulse length (SPL)
In diagnostic US, continuous wave sound cannot create anatomic images. True or false? True
A pulse of ultrasound is a collection of cycles that travel together. True or false? True
A pulse consists of individual cycles, but propagates as a single unit. True or false? True
Pulsed US has what two components? Transmit or talking time and receive time or listening time
The actual time from the start of a pulse to the end of that pulse. Pulse duration. Actual transmit time.
Characteristics of pulse duration Pulse duration is determined by the sound source only and is not adjustable by the sonographer
Typical values of pulse duration 0.3-2.0 microseconds in diagnostic US
Finding pulse duration pulse duration = # cycles x period OR pulse duration = # cycles/frequency
Pulse duration proportionality PD is directly proportional to # of cycles in the pulse and the period and inversely proportional to frequency
Typical # of cycles in a pulse 2-4 cycles
Which type of pulse is more desirable in diagnostic imaging? Shorter duration pulses and pulses of shorter length because they create images of greater accuracy.
The distance that a pulse occupies in space Spatial pulse length (SPL)
Typical values of spatial pulse length 0.1-1.0 mm in soft tissue
Characteristics of spatial pulse length Spatial pulse length is determined by both the source and the medium just like wavelength. It cannot be adjusted by the sonographer.
Finding spatial pulse length spatial pulse length = # of cycles x wavelength
Spatial pulse length proportionality SPR is directly proportional to the # of cycles in the pulse and wavelength and inversely proportional to frequency
The time from the start of one pulse to the start of the next pulse Pulse repetition period (PRP)
Typical value of pulse repetition period 100 microseconds - 1 millisecond (about 100-1000 times longer than pulse duration)
Characteristics of pulse repetition period PRP is determined by the sound source only and the imaging depth, not the medium. The sonographer can change the PRP and adjust the depth of view which alters the prp
PRP is unrelated to period. It is related only to depth of view. True or false? True
Pulse repetition period and imaging depth are directly related. True or false? True
Only the listening time is affected by change of depth, not the pulse duration. True or false? True
The number of pulses that an US system transmits into the body each second Pulse repetition frequency (PRF)
Typical value of pulse repetition frequency 1000-10,000 Hz
Characteristics of pulse repetition frequency PRF is determined only by the sound source and the max imaging depth of the system. The sonographer can change PRF by adjusting the depth of view
PRF is unrelated to frequency. it is related only to depth of view. True or false? True
Pulse repetition frequency proportionality PRF and depth of view are inversely proportional. PRF & PRP are also inversely related.
PRF and PRP have a reciprocal relationship. True or false? True
The percentage or fraction of time that the system transmits a pulse Duty factor
Typical dimensions of duty factor 0.002-0.005 or 0.2%-0.5% in clinical imaging
US systems spend a very small percentage of time transmitting and a very large percentage of time receiving. True or false? True
The duty factor for continuous wave sound is 100%. True or false? True
Characteristics of duty factor DF is determined by the sound source only. The sonographer can change the duty factor by changing the depth of view.
Duty factor proportionality DF is inversely proportional to imaging depth
Finding duty factor Duty factor = (pulse duration/PRP) x 100
Created by: gillybruursema
Popular Sonography sets

 

 



Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
Retries:
restart all cards