Change: There were only format changes (bold, italics, etc.) in this version. See this version for details. (Word count: 2049)

Change: The greater R, the greater the degree of reflection. i.e. R for a soft tissue interface such as liver and kidney is 0.01, i.e. only 1% of the sound is reflected. Muscle/bone interface 40% is reflected and for a soft tissue/air interface 99% is reflected.This is the   View changes from previous version. (Word count: 2145)

Change: each other to form a wavefront wich then determinates the direction of wave travel. The intensity at any point within the beam is determined by the sum of the contributions from all the pointsources. Interferences occurs between the waves from the pointsources, leading to variation in intesityintensity within   View changes from previous version. (Word count: 2082)

Change: Sound speed (c) is equal to one over the square root of the density times compressibility. OR c= square root compressibility / square root density.   View changes from previous version. (Word count: 2094)

Change: depth, and frequency decreases linearly with depth. Diffuse Scatter Diffuse scatter occurs when an objects size relative to the wave length becomes smaller. Imagine placing a thin stick upright in   View changes from previous version. (Word count: 855)

Change: ImpedenceImpedance is a property of a tissue defined as a product of density of the tissue and velocity of sound in that tissue. Denoted as Z = d ( kg/m3) X c ( m/s2) Reflection co-efficient ( R) is ratio of intensity of reflected wave to incident wave.   View changes from previous version. (Word count: 982)

Change: When a sound wave travels through two mediums of the same density and acoustic impedance the energy of the sound wave travels through the second   View changes from previous version. (Word count: 989)

Change: VariousInteractions interactions of ultrasound with soft tissues When ultrasound wave passes through tissues,1) There is reduction in amplitude and intensity of ultrasound wave.This is called attenuation .2) There is change in direction and velocity of the ultrasound wave and this is called refractionDefination:- Attenuation   View changes from previous version. (Word count: 629)

Change: Created by AndyC Jul 9 2008, 8:08 AM EDT for: no reason given