Ch.4 pulse duration

Why are the five additional parameters needed for?

to completely describe pulsed sound

In diagnostic ultrasound, blank, cannot create anatomic images?

continuous wave

What do imaging systems produce?

short bursts, or pulses, of acoustic energy to create the image

What is a pulsed wave?

a collection of cycles that travel together

What must a pulse have?

A beginning and an end

How does the entire pulse move, despite being made up of individual cycles?

as one unit

What are the two components of pulsed ultrasound?

transmit; talking time and receive; listening time

What is pulse duration?

the actual time from the start of a pulse to the end of that pulse/ a single transmit or talking time

What are the units for pulse duration?

reported in time/ units such as microseconds

What are the typical values for pulse duration?

0.3-2.0 microseconds

What is pulse duration determined by?

the sound source only

Is pulse duration adjustable?

no

What is pulse duration equal to?

the number of cycles in each pulse, multiplied by the period of each cycle

What is pulse duration directly proportional to?

number of cycles in the pulse, and period

What is pulse duration inversely proportional to?

frequency

What two characteristics represent pulses with long duration?

many cycles in the pulse, or individual cycles with long periods

What two characterisitics represent a pulse with short duration?

few cycles in the pulse, or individual cycle with short periods

What type of pulse duration is more desirablefor diagnostic imaging?

short duration pulses because images have higher accuracy