Ultrasound Physics-Test 1
Terms
undefined, object
copy deck
- In diagnostic US, info is often displayed in ____
- graphical form
- The ____axis, or ___axis runs side to side
- horizontal
- The ____axis, or ___runs up and down
- vertical
- Cholesterol and longevity
- inversely related
- smoking and likelikhood of Cardiovascular disease
- directly
- hours spent exercising and weight
- inversely related
- what is the unit of area?
- cm2 or ft2
- units of volume?
- cm3 or ft3
- Increase by a factor means ___
- multiply
- decrease by a factor means ____
- divide
- A number in scientific notation form with a positive exponent has a value of ____
- greater than 1
- a number in scientific notation form with a negative exponent has a value ____
- less than 1
- a number in scientfic notation form with exponent of zero has a value ____
- between 1 and 10
- How many milliliters are in 8 liters?
- 8000 liters
- How many cm are in 3 meterss
- 300
- How many kilometers are in 3000 meters
- 3
- How many milliliters are contained in a jar filled with 5 liters of fluid?
- 5000
- HOw many liters are contained in 80ml of fluid?
- .080
- How much bigger is a thousand than ten?
- 100
- How much bigger is a billion than million
- 1000
- How much smaller is a 100 than a thousand?
- 1/10
- In diagnostic US, sound pulses travel through biologic tissue or _____
- media
- All waves carry ___from one location to another.
- energy
- Sound is a ____wave in which particle move through a medium. The molecules in the meduim vibrate back and forth from a fixed position.
- mechanical
- Sound CANNOT travel through a ____; it must travel through a _____
- vaccumm; medium
- When sound travels through a medium, molescules are alternately ___ and ____
- compressed and rarefied
- Sound travels in a ____line
- straight
- Sound waves are _____waves
- longitudnal
- The effects of the medium upon the sound wave
- acoustic propagation properties
- The acoustic variables ___,_____,____are used to distinguish between sound waves and other types of waves
- pressure, distance, density
- If one of the acoustic variables has a rhytmic oscillation, then the wave is a sound wave.If something other than pressure, distance, density oscillates in a wave, then what?
- it is not a sound wave
- sound waves are also called
- acoustic waves
- concentration of force in an area
- pressure
- concentration of mass in a volume
- density
- measure of particle motion
- distance
- units of pressure
- pascals (Pa)
- units for density
- kg/cm3
- units for distance
- cm,mm
- ____acoustic parameters are used to accurately _____
- describe the characteristics of the soundwave
- What are the 7 acoustic parameters:
- period, frequency, amplitude, power, intensity, wavelength, power, propagation speed
- In a _____wave, particles move in a direction that is perpendicular to the direction that the wave propagates
- transverse
- In a ______wave, particles move in the same direction that the wave propagates.
- Longitudnal
- A pair of waves are considered in phase when _____
- when their peaks (maximum values) occur at the same time at the same location. SYCHRONIZED
- When two waves are at Out of Phase, what is occuring?
- their peaks occur at different times and so do their troughs: OUT OF STEP
- Multiple beams may arrive at an identical location at exactly the same time.The waves lose their individual characteristics at that moment and combine to form a single wave. This combo is called:
- called INTERFERENCE
- The interference of a pair of In-phase waves results in the formation of a single wave of greater amplitude than either of its components:
- Constructive Interference
- THe interference of a pair out of phase waves results in the formation of a single wave of lesser amplitude than either of its components. This combo is called
- destructive interference
- At some moment in time, the waves are in phase and the interference is constructive, while at other moments the waves are out of phase and it is destructive. Therefore when frequencies of the waves differ, what happens?
- both constructive and destructive interference occur
- ______describe features of a sound wave
- parameters
- The ___of a sound wave is the US system and transducer
- source
- The time it takes a wave to vibrate a single cycle or the time from the start of a scycle to the start of a next cycle
- period
- Units of period
- reported in time!
- Typical values of period
- .1 to 0.5 microseconds
- period is determined by____
- the sound source only
- the number of particular events that occurs in a specif duration of time
- frequency
- In Diagnostic US, the frequency of a wave is describe as ______
- the number of cycles that occurs in one second
- Unit of frequency
- reported in units of per second, 1/second, hertz, or Hz.
- Typical Values in frequency
- 2 MHz to 10 MHz
- Period is determined by the ___
- sound source
- Frequency of a sound wave is determined by ____
- sound source
- How did ultrasound get its name?
- Sound is classified based on the ability of humans to hear it
- less than 20 Hz
- infrasound
- between 20 Hz and 20 kHz
- audible sound
- greater than 20 kHz
- ultrasound
- Why is frequency important?
- affects penetration and image quality
- Period and frequency are _____related to each other
- inversely related
- Which of the following waves is infrasonic?
-
A. 4 MHz
B. 400kHz