Detection of bone density with ultrasound

The broadband ultrasound attenuation (BUA) and the speed of sound (SOS) are usually measured to evaluate the bone density. However, as previous studies showed that the BUA is sensitive to repositioning and soft tissue, the reproducibility of measurement will be difficult to achieve. In our system, we used Net Delay Time (NDT) value, pressure detection and several signal-processing techniques to obtain the reproducibility. Through in-vivo examinations, the root-mean square coefficient of variation (CVRMS%) did not significantly change for SOS(about 0.4),BUA (about 2.2).Comparing with the results of other research, we found that the reproducibility of our system was better.