Attenuation Flashcards
What is the term used for “a decrease in sound energy as the wave propagates”?
Attenuation
As depth increases, what happens to attenuation?
Increases as it travels further into the body
What are the units of attenuation?
decibels (dB)
What is the dominating factor that attributes to attenuation?
ABSORPTION (conversion of sound to heat)
How can attenuation be compensated for?
Use TGC’s
What does attenuation encompass?
- Absorption (dominant factor)
- Scattering
- Reflection
Does using a high frequency probe attribute to more or less attenuation?
HIGHER
Would you use a high or low frequency probe to scan deeper structures?
Lower frequency as it can attenuate further into the body
What causes increased absorption of the ultrasound beam?
- Higher transmitting frequency
- Denser mediums
- Distance of sound travel
Do fluids have low or high absorption?
Very low
In more dense mediums, what artifact may you run into due to increased absorption?
Acoustic shadowing
Complete absorption leads to what artifact?
Acoustic shadowing
As attenuation increases, what happens to the attenuation coefficient?
Increases
What can compensate for the affect of attenuation in an image?
TGC’s - enhances the signal
Which of the following mediums would have the smallest dB of attenuation?
A) Amniotic Fluid
B) Blood
C) Bone
D) Soft tissue
A) Amniotic Fluid
