Characterization of Cancellous Bone Microstructure by Using Ultrasonic Apparent Backscatter Imaging

In this paper, a high resolution transducer was used to conduct ultrasonic backscatter parametric images based on the measurements of uncompensated backscatter coefficient (BC) and apparent integrated backscatter (AIB), which can provide information related to cancellous bone microstructure. BC&AIB images from 26 bovine cancellous bone samples in vitro were constructed to analyze their abilities of characterizing cancellous bone status. For each of 26 bone samples, mean value and standard deviation (SD) of BC&AIB values within a region of interest (ROI) were calculated and then compared with bone microstructural parameters obtained from mu-CT 3D reconstruction. Results demonstrated that BC and AIB have mediate, but significant correlations with trabecular spacing (Tb.Sp). It was also found that spatial variation of BC or AIB values was significantly related with bone microstructural parameters.