A NOVEL METHOD TO MEASURE ACOUSTIC SPEED OF BONE TISSUE

Acoustic speed is an important parameter that can be used to character ize bone tissue for evaluation of osteoporosis, Traditional approaches for measuring acoustic speed require knowledge of either the specimen thickness, which is sometimes difficult to obtain from biological tis sues, or the reference fluid velocity that, moreover, is an unknown pa rameter for internal tissue in irt vivo measurement, In this paper, a new method is proposed to measure acoustic speed from dual reflected u ltrasound signals, This technique utilizes two transducers placed on t he same side of the test object; one for transmitter and receiver, and the other one for receiver only, The acoustic speed of the test objec t is based on the information of time-of-flight from the signals recei ved by both transducers and the separation distance between the transd ucer pair, The technique developed here not only eliminates the requir ement of knowledge of specimen thickness, but also shows a feasibility for clinical applications, The results of different porcine and bovin e bone samples measured in vitro by this technique are in good agreeme nt with those measured by other published methods, In vivo measurement results of 10 healthy young volunteers' tibias are also reported. (C) 1997 World Federation for Ultrasound in Medicine & Biology.