SAPA Love Story
Flower Power
Attenuating Circumstances
Keep a positive Amplitude
Scatter Brain
100
Spatial Pulse Pulse Average
What is SAPA?
100
It is the rate at which energy is transferred from one part of a system to another and its units include watts and milliwatts.
What is power?
100
Who knows?
If two sound waves travel through a medium, which travels faster - a bass horn wave or a flute wave?
100
This will happen if the path length remains the same but the frequency increases.
What is an increase in attenuation?
100
This happens to transmitted sound when a 2.5MHz transducer is switched to a 5Mhz transducer.
What is a wavelength that is half as long?
200
It relates to distance or space.
What is Spatial?
200
It is the rate at which energy passes through a unit area and its units include W/cm2 and mW/cm2.
What is intensity?
200
Heat energy
What does sound change into when it's absorbed?
200
Another name for it is orthogonal incidence.
What is another name for normal incidence?
200
4080m/s
What is the acoustic velocity of ultrasound in bone?
300
It yields the lowest value (intensity) for a given beam.
What is SATA.
300
It is proportional to amplitude squared.
What is intensity.
300
More absorption takes place when using a transducer with a ______________ frequency.
What is higher ?
300
It is approximately .50 x frequency.
What is the attenuation coefficient of ultrasound in soft tissue?
300
It is the product of density of the medium multiplied by the propagation speed of sound.
What is impedance?
400
It is the greatest intensity found across the beam.
What is SPTP?
400
It is the maximum variation that occurs in an acoustic variable.
What is amplitude?
400
The brightness of the dot is proportional to this echo signal in B Mode imaging.
What is the echo signal amplititude?
400
It is an attenuation drop of 6 decibels.
What is an intensity reduction of one quarter? (1/4)
400
It is the fraction of time that pulsed ultrasound is on and it has no units.
What is the duty factor?
500
It is the average for all values (intensities) found in a pulse.
What is Pulse Average (PA)?
500
It is the percentage of ultrasound energy that is bounced back at the boundary between two media.
What is the Intensity Reflection Coefficient (IRC)?
500
With perpendicular incidence, in order for sound to be reflected, this must happen.
What are different acoustic impedances?
500
It is the dominant component of attenuation.
What is absorption?
500
It is the redirection of sound in many directions by rough surfaces, heterogeneous media, or particle suspensions.
What is Scattering?
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