physics ultrasound

TRUE OR FALSE acoustic parameters are used to describe the characteristics of sound waves.

True

TRUE OR FALSE interference occurs due to in-phase and out-of-phase sound waves

True

how is the age of a loaf of bread related to its freshness?

inversely

how many hertz is 5Mhz?

5,000,000

what is the reciprocal os 1/6

6

all of the following are true about sound waves expect

a. they are transverse

b. they are acoustic

c. they are pressure waves

d. they move energy

a. they are transverse

what units are used to report the pressure of a sound beam

pascals

the study of the effects of sound waves on biological tussle is know as

biologic effects

sounds is a _ and _ wave

mechanical, longitudinal

list these metric terms in increasing order;

mega, micro,mili, hecto, deca, deci

micro, milli, deci, deca, hecto, mega

hair color is what to shoe size

unrelated

clothing size is that to ones weight

directly related

santa is what to Christmas

related

grades are what to partying time

inversely related

2 and ½ are what

reciprocals

10⁹ what prefix

giga

10 ⁶ what prefix

mega

10³ what prefix

kilo

10² what prefix

hecto

10¹ what prefix

deca

10 ^-1 what prefix

deci

10^-2 what prefix

centi

10^-3 what prefix

mili

10 ^-6 what prefix

micro

10^-9 what prefix

nano

how many millimeters are in 8 liters?

8000 liters

how many centimeters are in 3 meters

300 centimeters

what is the reciprocal of 1/8

8

how many hertz is 3Mhz

3,000,000

how many millimeters are contained in a jar filled with 5 liters of fluid

5000 millimeters

how much bigger is a thousand than ten

100 times

how much bigger is a billion than a million

1,000 times

what do waves transfer from one location to another

energy

which of the following best describes sound waves.

a. a series of compression and rarefactions

b. waves that are heard by man

c. movement of molecules and energy from ones location to another.

d. waves that are used to make images of anatomy

a. a series of compressions and rarefactions

which of the following terms does not belong with the others?

a. compression

b. region of high density

c. region of high pressure

d. wide molecular spacing

d wide molecular spacing

variations in all of the following identify specific waves as acoustic waves except.

a. pressure

b. parameters

c. density

d. acoustic variables

b. parameters

what is not true about sound waves

they are not transverse

what is not true about acoustic parameters

pressure is not an acoustic paremeters

what best describes sound waves

longitudinal, pressure wave

two waves are traveling in a medium and arrive at a location at the same time. what event takes place.

interference

which type of wave will exhibit both constuctive and destructive interference

waves of different frequency

what unites are used to port the pressure of a sound be a,

Pascal

What is the definition of acoustic properties

the effects of the medium upon the sound wave

what is the definition of biologic effects

the effects of the sound wave upon the biological tissue through which it passes

what are the acoustic variables

pressure, density, and distance

what is the unit for pressure

pascals

what is the unit for density

kg/cm³

what is the unit for distance

cm, ft, mile

what are the 7 acoustic parameters

period, frequency, amplitude, power, intensity, wavelength, and propagation speed

what is the source of a soundwave

ultrasound system and transducer

what is the tissue called

the medium

defined the period

time of a start of one cycle to the start of the next

what are the units of a period

microseconds

what is period determined by

only by the sound source

can the sonographer change the period

No

describe a frequency

the number of specific events during specific time

what are the units for frequency

1/sec=1hertz

what are the typically views in clinical imagine of frequency

ranges from 2MHz to 15MHz or 2mil to 15mil

what is frequency determined by

sound source only

can the sonographer change the frequency

No

how are frequency and period related?

inversely related and they are reciprocals

how many hz is infrasound

less than 20Hz

how many hz is audible sound

between 20 hz and 20kHz

how many hz is ultrasound

greater than 20kHz

what wave has the longest period

a. 2Mhz

b. 4,000 Hz

c. 6Hz

d. 1kHz

c 6Hz

of the four waves whos period has the highest frequency?

a. 8 s

b. 80 milliseconds

c. 8Ms

d. 800 ks

b. 80 milliseconds

what are the three big parameters of a sound wave

amplitude, power, and intensity

describe amplitude of a wave

the bigness of the wave; difference between the max or min of the wave

what are the units of amplitude?

any units of the acoustic variables can be used

what typical values do we see in clinical imaging for amplitude

1mil pascals (1MPa) to 3mil pascals (3MPa)

what is the amplitude determined by

originally by the sound source only, then it decreases and depends on the sound wave and medium

can the sonographer adjust the amplitude of the wave

Yes

What is Peak-To-Peak Amplitude

difference between the max and min values so its twice the amplitude

define power

bigness of the wave; rate of energy transer

what is the units for power

watts

what are the typical values in a clinical imaging for power

0.004 to 0.09 watts (4 to 90 milliwatts)

how is power determined

orgianally by the sound source then decreases and depends on the medium and wave

is the amplitude adjustable by the sonographer

Yes

How are amplitude and power related

when power increase so does amplitude: when power decreases so does amplitude

what is power proptional to

power is proportional to amplitude ²

define intensity

bigness of a wave: energy in a sound be a,

what are the units of intensity

watts/squarecentimeters or W/cm²

typical values of intensity in a clinical imaging looks like what

0.01 to 300 W/cm²

what is intensity determined by

sound source originally then can change depending on the sound wave and medium

is the insteniy adjustable by the sonographer

yes

what is the formula for intensity

intensity =power /area. W/cm²= w/cm²

what is the relationship between intesnsity and power

intensity is proportional to power

what is the relationship between intensity and amplitude

intensity is proportional to the waves amplitude²

define wavelength

distance or length of one complete cycle

what are the units of wavelength

mm, meters

typical values you see in clinical imaging are

0.1 to 0.8mm

how is wavelength determined

by the source and medium

can the sonographer adjust the wavelength

No

what is different between wavelength and period

wavelength is a length and period is a time

what is the relationship between wavelength and frequency

inversely related

what is the wavelength of 1Mhz sound in the soft tissue

1MHz and a wavelength of 1.54mm

why is wave length important to us

short wavelength are by higher frequency sounds. means higher quality images with greater details

define propagation speed

the rate which a sound wave travels through a medium

what is the units of propagation speed

meters per second mm/s

typical values in the body for propagation speed is

500 to 4000 m/s