What is a wave? CORRECT ANSWERS: A cyclical Transfer of energy
What kind of wave is a sound wave? CORRECT ANSWERS: A mechanical longitudinal wave
What are the types of interference? CORRECT ANSWERS: Constructive, Destructive and Partial
What is the Classification of Ultrasound? CORRECT ANSWERS: 20 mhz-200Hz
What is the classification of Diagnostic Ultrasound? CORRECT ANSWERS: 12mhz-2mhz
What is the propagation speed in soft tissue? CORRECT ANSWERS: 1,540 mhz
1.54 m/msec 154,000 cm/sec
A Longitudinal wave propagates by a series of ________ and ______ back and forth in the same direction as the wave propagates. CORRECT ANSWERS: Compression and Rarefaction
What are the acoustic variables of wave propagation? CORRECT ANSWERS: Pressure, Density, Temperature and particle motion
Equation for the frequency of the wave? CORRECT ANSWERS: f=1/p
Frequency and period are are determined by what? CORRECT ANSWERS: The source
What is the propagation velocity equation? CORRECT ANSWERS: If the Density increases what happens to the Bulk modulus and propagation velocity? CORRECT ANSWERS: The Bulk Modulus increases and the Propagation increases
If the density of the medium decreases what happens to the Bulk modulus and propagation velocity? CORRECT ANSWERS: The bulk modulus decreases and the propagation decreases
Stiffness is the same as what? CORRECT ANSWERS: Bulk Modulus
Stiffness and compressibility are __________ related CORRECT ANSWERS: Inversely
What is the equation for the wavelength? CORRECT ANSWERS: wavelength= c/f
What is the amplitude? CORRECT ANSWERS: Maximum variation of a variable from its mean
What are the equations for the amplitude? CORRECT ANSWERS: Max-Min
Mean-Min
Max-min/2 Power is proportional to the amplitude _______. CORRECT ANSWERS: Amplitude Squared
What is the definition of intensity? CORRECT ANSWERS: I=Power/Area
The top Diagnostic frequencies are limited by what? CORRECT ANSWERS: Penetration
Low frequencies a limited by what? CORRECT ANSWERS: Resolution
3 dB factor of CORRECT ANSWERS: 2
10dB factor of CORRECT ANSWERS: 10
What is attenuation? CORRECT ANSWERS: The conversion of sound into heat
What are the factors of attenuation? CORRECT ANSWERS: Absorption, Reflection and Refraction
What are the key factors of Absorption? CORRECT ANSWERS: It is the dominant form of attenuation and it increases exponentially w/ increasing frequency.
What are the two types of reflection? CORRECT ANSWERS: Acoustic and geometric
what are the kinds of geometric reflectors? CORRECT ANSWERS: - Specular reflectors
-Scatterers -Rayleigh scattering
What causes refraction? CORRECT ANSWERS: -Different propagation speeds -Obliques angle of incidence
What causes lateral Displacement? CORRECT ANSWERS: refraction, the machine is not aware
that refraction occurs.
What does total internal reflection caused by? CORRECT ANSWERS: Critical angle
What is the attenuation rate in soft tissue? CORRECT ANSWERS: 0.5
What is the Attenuation coefficient of soft tissue? CORRECT ANSWERS: 1/2fo
What is the Equation for conservation of energy? CORRECT ANSWERS: Reflection % + Transmission % = 100%
Describe anechoic CORRECT ANSWERS: No echogencity (Dark)
Describe Hypoechoic CORRECT ANSWERS: Low echogenicity (Dark)