Phys and Instrumentation Exam 1

the parameters of pulsed sound are…

pulse duration, spatial pulse length, pulse repetition frequency, pulse repetition period, duty factor

components of pulse ultrasound…

on and off time

pulse duration is the… unit…

length of pulse in time, microseconds

pulse duration equations (2)

cycles x period, cycles / frequency

pulse duration relationship to spatial period length, frequency

direct, inverse

pulse repetition period is the… unit…

time from start of one pulse to start of next, microseconds

an increased PRP means … listening time, … depth

increased, increased

spatial pulse length is the… unit…

length of pulse in distance, micrometers

spatial pulse length equation

cycles x wavelength

spatial pulse length relationship with wavelength

direct

pulse repetition frequency is the… units…

pulses per second, hz

PRP relationship to depth

direct

PRF relationship to depth

inverse

prp and prf relationship, equation

reciprocals, prf x prp = 1

duty factor is the…

percent of prp that is the transmitting time

pulse parameters controlled by sonographer; how?

duty factor, prp, prf; depth

duty factor relationship to depth

inverse

duty factor equation

pd / prp

shallow imaging …listening, …df, …prf, …prp (less or more than deep)

less, more, more, less

deep imaging …listening, …df, …prf, …prp (less or more than shallow)

more, less, less, more

sound is a … and … wave

longitudinal, mechanical

acoustic variables … a sound wave, include…

determine, pressure, density, distance

pressure’s unit

pascals

density’s unit (example)

kg/cm³

distance’s unit (example)

m

acoustic parameters … a sound wave, include…

describe, period, frequency, amplitude, power, intensity, wavelength, speed

period is the…, unit

length of a cycle in time, microsec

frequency is the…, unit

number of cycles per second, hz

period / frequency equation

period x frequency =1

period and frequency relationship

reciprocal

amplitude is the…, units include of the units of the…

difference between the maximum and average, acoustic variables

peak to peak amplitude formula

amplitude x 2

power is the, unit

rate of energy transfer, watts

amplitude and power equation

power prop. amp²

intensity is the…, unit

concentration of beam, watts/cm²

intensity formula

power/beam area

adjustable acoustic parameters; what is adjusted

intensity, power, amplitude; power

speed is…, unit

distance traveled in one second, hz/m

wavelength is the…, unit

distance of one cycle, micrometer

wavelength and frequency relationship

inverse

wavelength is determined by the…, speed by the…, all others by…

source and medium, medium, source

speed of sound in soft tissue (meters)

1540

wavelength equation

1.54 x frequency

in-phase waves are…, out-of-phase waves are…

constructive, destructive

ultrasounds are over … hz

20000

frequency affects… and … of ultrasounds

penetration, image quality

wavelength and speed relationship

unrelated

speed formula

frequency x wavelength

stiffness and speed relationship

direct

density and speed relationship

inverse

speed is a … based on the …

constant, medium

power, intensity, and amplitude relationship

direct

typical imaging frequency (… - …)

2-15 MHz

periods relationship to wavelength

proportional

stiffness of a medium aka

bulk modulus