Correlations between signal spectrum of ultrasonic backscatter and cancellous bone microstructure

Ultrasonic backscatter offers the advantage of directly analyzing some common fracture sites other than the calcaneus. Spectral centroid shift (SCS), an indicator of ultrasonic attenuation in the bone, is a potential parameter obtained from ultrasonic backscattered signals to represent the bone status. In this paper, twenty-six bovine tibia bones in vitro were scanned by a 10 MHz transducer and the ultrasonic backscattered signals were processed to obtain SCS at corresponding scan spots. Correlations were studied between mean/standard deviation (SD) of SCS values within a ROI of bones and bone structural parameters obtained from a ¿-CT. Results demonstrated that SCS has mediate and significant correlations with all the parameters obtained from ¿-CT (Tb.Th, r = -0.699, p < 0.01; Tb.Sp, r = 0.477, p < 0.05; BV/TV, r= -0.675, p < 0.01; BS/BV, r = 0.663, p < 0.01; BD, r = 0.663, p < 0.01). The SD of SCS was also significantly (p < 0.01) correlation with bone structural parameters. The high relationships between the ultrasonic parameter SCS and bone structural parameters hold promise for later implementing SCS to assess bone quality.