Measurement of the Human Calcaneus In Vivo Using Ultrasonic Backscatter Spectral Centroid Shift

Objectives-The aim of this study was to determine the relationship between the backscattered spectral centroid shift and the bone mineral density (BMD) in vivo and investigate the feasibility of using the backscattered spectral centroid shift to characterize the cancellous bone status. Methods-Ultrasonic backscatter measurements were performed in vivo on 1216 participants at the right calcaneus using an ultrasonic backscattered bone diagnostic system, and the backscattered spectral centroid shift was calculated at central frequencies of 3.5 and 5.0 MHz. The BMD values were measured at the sites of the lumbar spine and left hip by dual energy x-ray absorptiometry. Results-The study population included 592 male and 624 female participants aged 20 to 89 years. The correlations between the backscattered spectral centroid shift in the calcaneus and the spine and hip BMD were found to be statistically significant in both the male and female groups (P<.0001). Linear regression showed that the spectral centroid shift at 3.5 MHz had negative correlations with the spine BMD (R=-0.65 for male participants; R=-0.67 for female participants) and hip BMD (R=-0.64 for male participants; R=-0.64 for female participants). The spectral centroid shift at 5.0 MHz was also found to be closely related to the spine BMD (R=-0.68 for male participants; R=-0.68 for female participants) and hip BMD (R=-0.66 for male participants; R=-0.64 for female participants). Conclusions-The moderate correlations observed between the spectral centroid shift and the spine and hip BMD demonstrate that the ultrasonic backscattered spectral centroid shift may be a useful measurement for assessment of the cancellous bone status.