Pulsed Wave Chap 4 Flashcards
(21 cards)
What is the Pulse Echo technique?
Ultrasound technique that collects information via pulsing
What are the two components of a single unit pulse in ultrasound?
Transmit and receive
How is an image formed using the Pulse Echo technique?
1) A sound wave is transmitted into the body
2) It reflects off of a structure
3) Returns to the transducer
4) Information is processed for display
What is pulse duration?
Time it takes for one pulse, measured in microseconds
What determines pulse duration?
The source
What is the formula for calculating pulse duration?
PD = #cycles x period
What is spatial pulse length?
Length of one pulse, measured in millimeters
What determines spatial pulse length?
The source and medium
What is the formula for calculating spatial pulse length?
SPL = wavelength x #cycles
What is pulse repetition period (PRP)?
Time from the start of a pulse to the start of the next pulse, measured in milliseconds
What determines pulse repetition period?
The source
What is the formula for calculating pulse repetition period?
PRP = sec/pulse = 1/PRF
What is pulse repetition frequency (PRF)?
Number of pulses per second, measured in megahertz
What determines pulse repetition frequency?
The source
What is the formula for calculating pulse repetition frequency?
PRF = 1/PRP
True or False: A longer pulse repetition period means a shorter pulse repetition frequency.
True
True or False: A longer pulse repetition frequency means a longer pulse repetition period.
False
What is the duty factor?
Time of the entirety of the pulse, no units
What is the formula for calculating duty factor?
DF = PD/PRP
What is the duty factor for a continuous wave?
100%
What is the duty factor for a pulse wave?
Always less than 100%
