Estimation of the mean spacing of trabecular bones using autoregression cepstrum

The autoregression (AR) cepstrum is put forward to estimate the mean spacing of trabecular bones in cancellous bone based on ultrasonic backscatter signal. The ultrasonic backscatter signals from bovine tibiae and human calcaneus cancellous bone in vitro were investigated by performing autoregression (AR) cepstrum, and the mean spacing of trabecular bones in cancellous bone was estimated. The results show that the mean spacing of trabecular bones and the apparent density of cancellous bone have a close relationship. The mean spacing of trabecular bones increases with the reduction of the apparent density. The AR cepstrum can be used to estimate accurately the mean spacing of trabecular bones in cancellous bone.