Quantitative ultrasound measurement of bone density based on dynamic time window: suitable for the measurement of speed of sound in radius.
OBJECTIVE
Our objective was to evaluate the dynamic time window method (DTWM) for the measurement of speed of sound (SOS) at the 1/3 distal radius in 10 human subjects in vivo. DTWM, which is based on our proprietary probe, is a new method for obtaining the accurate time of flight (TOF) of the first arriving signal (FAS).


METHODS
This study compared DTWM with three conventional methods, i.e., threshold value method, first of maxima, and zero-crossing method, for the measurement of TOF of FAS.


RESULTS
The highest correlation between SOS and bone mineral density (BMD) was found in the 10 human subjects using DTWM (R DTWM = 0.81, p < 0.005) rather than the three conventional methods (R = 0.37-0.41, p > 0.05). The individual short-term coefficient of variation (CV, from 0.07 to 0.27) and Root-Mean-Square (RMS) of the average CV (CVRMS, 0.18) were used to evaluate the reproducibility of our method (DTWM).


CONCLUSIONS
Despite the small population, the results suggest that DTWM improves the accuracy of recognition of SOS in vivo, and might be applied to optimize the clinical assessment of long cortical bone osteoporosis and fracture risk profile.
Institute and Intelligent of Machines, Chinese Academy of Science, Hefei, 230026, Anhui, People's Republic of China.|Department of Automation, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
Yang
Y
Xu
Institute and Intelligent of Machines, Chinese Academy of Science, Hefei, 230026, Anhui, People's Republic of China.
Yubing
Y
Xu
Institute and Intelligent of Machines, Chinese Academy of Science, Hefei, 230026, Anhui, People's Republic of China. edanyang@mail.ustc.edu.cn.
Yanyan
Y
Chen
Institute and Intelligent of Machines, Chinese Academy of Science, Hefei, 230026, Anhui, People's Republic of China.
Zenghui
Z
Ding
Institute and Intelligent of Machines, Chinese Academy of Science, Hefei, 230026, Anhui, People's Republic of China.
Zuchang
Z
Ma
Institute and Intelligent of Machines, Chinese Academy of Science, Hefei, 230026, Anhui, People's Republic of China.
Yining
Y
Sun
D000328:Adult; D000465:Algorithms; D015519:Bone Density; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D013016:Sound; D013997:Time Factors; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*
Dynamic time window method (DTWM); Quantitative ultrasound (QUS); Radius; Speed of sound (SOS); Time of flight (TOF)