A method is discussed for measuring isentropic and isothermal components of B/A. Measurements of these parameters of excised human tissues indicate fatty tissues to be highly nonlinear to sound propagation. The isentropic and isothermal components of B/A of aqueous solutions of alcohol go through a minimum at 10% volume fraction as the concentration of alcohol is increased. Sound speed shows a maximum at 20% concentration. These changes in acoustic parameter with alcohol concentration are qualitatively explained in terms of the variations in the free and the bound states of water due to the addition of alcohols. The possibility of imaging weighted nonlinear parameter of excised breast by measuring the difference frequency generated by transmitting two frequencies of ultrasound is also discussed.
ASJC Scopus subject areas