中文摘要：

采用超声背散射信号的质心偏移量来评价松质骨。并对牛胫骨和人体跟骨中背散射信号的质心偏移量与松质骨表观密度的关系．以及人体跟骨松质骨中背散射信号频谱质心位置与年龄的关系进行了分析讨论。分析结果表明。随松质骨表观密度的增大，背散射信号频谱的质心向低频方向移动；随年龄的增大，质心位置越接近于发射超声的中心频率。根据超声背散射信号质心偏移量的大小，可用于评价松质骨健康状况。

英文摘要：

The spectral centroid shift （SCS） of ultrasonic backscattering signals is introduced to assess cancellous bones. Relationships between the SCS of backscatter signals from bovine tibiae and human calcaneus cancellous bone in vitro and the apparent density of cancellous bone, the spectral centroid positions （SCP） of backscattered signal in human calcaneus cancellous bone in vivo and ages were measured and discussed, respectively. The results show that the spectral centroid of the backscatterer signals is dowushifted to lower frequency with increase of the apparent density of cancellous bone. The SCP of backscattering signals approach the emissive center frequency with increase of ages. According to the size of SCS of ultrasonic backscattered signals, the status of cancellous bone may be assessed.