Fig. 1. Experimental setup for ultrasonic measurements.超声测量实验装置图

Fig. 2. Backscatter signal of cancellous bone sample (ROI, region of interest).松质骨样本的超声背散射信号(ROI, 感兴趣区域)

Fig. 3. Relationship between the measured frequency-dependent attenuation and the standard frequency-dependent attenuation: (a) the spectral shift method; (b) the spectral difference method; (c) the spectral log difference method; (d) the hybrid method.频散衰减系数测量值与透射法频散衰减标准值的关系　(a)谱移法; (b)谱差法; (c)谱对数差法; (d)混合法

Fig. 4. Frequency-dependent attenuation compensated signal from cancellous bone.频散衰减补偿后的松质骨超声背散射信号

Table 1. Frequency-dependent attenuation coefficient measurement results.