Next Flashcards
1Hz is equal to..
1 cycle/second
1kHz is equivalent to..
1000 cycle/second
1MHz is equivalent to
1,000,000 cycle/second
It Travels parallel to the line of propagation producing longitudinal waves.
Ultrasound
It Travels in a straight line.
Ultrasound
It is a concentration of force within an area
Pressure (Pascals/Pa)
Units of Pressure
Pascals or Pa
It is a concentration of mass within a volume
Density (kg/cm3)
Measure of particle motion
Distance (cm, feet, miles)
Unit of Density
kg/cm3
Units of Distance
cm, feet, miles
A particles move back and forth in the same as wave
Longitudinal Waves
A particle moves in a perpendicular direction (right angles or 90 degrees) to the direction of the waves
Transverse Waves
The particles closest together
Compression
The particles farthest together
Rarefaction
____________ is dependent on the type of tissue the sound wave is traveling through.
Attenuation
As the ultrasound beam travels through the body it loses energy.
Attenuation
What are the different interactions of soundwaves?
Absorption
Reflection
Scattering
Refraction
Divergence / Diffraction
Also known as Backscatter
Reflection
The higher the frequency of the soundwave, the greater the amount of absorption that will occur.
Absorption
The energy is transferred from the soundwave into the medium through which it is travelling.
Absorption
The main factor causing attenuation of the ultrasound beam.
Absorption
THE ENERGY IS REFLECTED BACK FROM AN INTERFACE I.S KNOWN AS ECHO
Reflection
ThePOSTERIORSHADOWINGcaused by BOWEL GAS often leads to ______________________of certain organs
Non Visualization
This normally happens to BONES
and STONES
Shadow
The wavelength shortens if the velocity is decreased, and vice versa.
Refraction
Refers to the change in the direction of an ultrasound beam when moving between two tissues that have different speeds of sound (acoustic velocities)
Refraction
It can cause artifacts.
Refraction
REDIRECTIONOFACOUSTIC ENERGY IN NUMEROUS DIRECTION
Scattering
WEAK SIGNALS =
White ultrasound image impression
The ultrasound waves diverges (spreads out) as it moves away from the source
Diffraction
It is determined by the relationship between the width of the source (aperture) and the wavelength of the wave.
DIFFRACTION
Echogenicity:
White
hyperechoic
Echogenicity:
Light Gray
Isoechoic
Echogenicity:
Dark Gray
Hypoechoic
Echogenicity:
Black or Dark
Anechoic
