Pulse Wave

Continuous wave doppler

ultrasound mode using two crystals

one transmits continuously and the other receives continuously

Which wave form has no image capability

continuous wave

What wave form has no range resolution

continuous wave

Pulsed wave doppler

ultrasound mode using short bursts of sound

what wave form provides range resolution

pulsed wave

Echo return time determines

distance of structures

shorter pulses equals

better resolution

range resolution

ability to distinguish between two structures at different depths

range resolution is dependent on

SPL

Shorter SPL equals

better resolution

round trip effect

returning echoes from two reflectors are separated by twice the distance between the reflectors

round trip effect improves resolution by a factor of

2

pulse duration

time the transmit pulse lasts

pulse duration units

microseconds (us)

Pulse repetition period

time from beginning of one pulse to the beginning of the next pulse

Pulse repetition period is determined by

imaging depth

pulse repetition frequency

number of pulses per second

PRF is the reciprocal of

PRP

PRF units

Hz

Duty factor

percentage of time the system is on (transmitting and listening)

DF formula

PD/PRP

Higher DF equals

greater risk of bioeffects

SPL formula

#cycles X wavelength

Shorter SPL equals

better axial resolution

Resoltuion

general term for the systems ability to distinguish structures

Smaller values equal

better resolution

Axial resolution

along the sound beam axis

Temporal resolution

resolution in time, how well movement is displayed

Higher frame rates equals

better temporal resolution