Describing Pulsed Waves

Question 1

What is pulse duration (PD)?

Answer 1

The actual time from the start of a pulse to the end of that pulse; single on-time/transmit

Important parameter for understanding wave behavior in ultrasound.

Question 2

What is pulse repetition period (PRP)?

Answer 2

The time from the start of one pulse to the start of the next pulse

Critical for determining imaging depth.

Question 3

What is pulse repetition frequency (PRF)?

Answer 3

The number of pulses that an ultrasound system transmits into the body each second

Higher PRF yields better image quality.

Question 4

What is spatial pulse length (SPL)?

Answer 4

The distance that a pulse occupies in space from the start to the end of a pulse

Influences the axial resolution of the ultrasound image.

Question 5

What is duty factor (DF)?

Answer 5

The percentage or fraction of time that the system transmits a pulse

Higher duty factor can improve image quality.

Question 6

What is the formula for calculating pulse duration (PD)?

Answer 6

= # cycles / frequency; # cycles x period

Essential for determining the time characteristics of a pulse.

Question 7

What is the formula for pulse repetition period (PRP)?

Answer 7

= PD + off-time; = 1 / PRF

Helps in understanding the timing of pulse transmissions.

Question 8

What is the formula for pulse repetition frequency (PRF)?

Answer 8

= 1 / PRP

Indicates how frequently pulses are emitted.

Question 9

What is the formula for spatial pulse length (SPL)?

Answer 9

= # cycles x wavelength

Important for assessing the spatial characteristics of ultrasound waves.

Question 10

What is the formula for duty factor (DF)?

Answer 10

= (PD / PRP) x 100; = (PD x PRF) (100)

Affects the efficiency of pulse transmission.

Question 11

What is the typical value of pulse duration (PD)?

Answer 11

0.5-3.0 us

Indicates the range of pulse durations commonly used in ultrasound.

Question 12

What is the typical value of pulse repetition period (PRP)?

Answer 12

0.1-1.0 ms

Relates to the time intervals between pulse emissions.

Question 13

What is the typical value of pulse repetition frequency (PRF)?

Answer 13

1-10 kHz

Reflects the frequency of pulse transmissions in ultrasound systems.

Question 14

What is the typical value of spatial pulse length (SPL)?

Answer 14

0.1-1.0 mm

Important for determining the axial resolution in imaging.

Question 15

What is the typical value of duty factor (DF)?

Answer 15

0.2-0.5%

Indicates the efficiency of the ultrasound system in pulse transmission.

Question 16

True or False: Higher duty factor results in more listening time in ultrasound imaging.

Answer 16

False

Higher duty factor means less listening time.

Question 17

Fill in the blank: A longer PRP results in _______.

Answer 17

Lower PRF

This relationship is crucial for understanding pulse timing.

Question 18

Fill in the blank: The time from the start of one pulse to the start of the next pulse is known as _______.

Answer 18

Pulse Repetition Period (PRP)

Essential for timing in ultrasound imaging.

Question 19

Fill in the blank: The distance that a pulse occupies in space is referred to as _______.

Answer 19

Spatial Pulse Length (SPL)

Important for image resolution in ultrasound.