Ultrasound Flashcards
Between what hertz is ultrasound?
20kHz to 20 MHz
What is the equation for frequency?
f= 1/T
Downside of higher frequency in ultrasound? Upside?
cannot penetrate as deeply but better resolution
What does C5-1 mean on the probe?
5 megahertz to 1 megahertz
average speed of sound inside of soft tissue?
1540 m/s
What is acoustic impedance?
reflection of a sound wave whenever the beam encounters an interface formed by two tissues having different acoustic impedance
better acoustic impedance = better what?
degree of reflection
specular vs diffuse reflection
specular- smooth, diffuse- scattering
Attenuation
decrease in sound amplitude with increasing distance traveled
Does higher or lower frequencies attenuate faster?
higher
Whiter things have a greater or lesser strength of reflection?
greater
What is the ALARA principle?
As Low As Reasonably Acheivable
For refraction of a sound wave to occur, which of the following must occur?
The incident sound wave is non-perpendicular to the interface and
The speed of sound must be different on the two sides of the interface
What is a transducer?
Something that converts one form of energy to another.
What is an example of continue echo?
Doppler and fetal heart tones
Footprint
what touches the body of the patient